Testers Hub

SOAPUI Tool

noreply@blogger.com (kareem) — Mon, 18 Dec 2017 04:10:00 -0800

SoapUI tool is developed by Smartbear and is used to test web services.

· Can do Functional, Load & Performance testings

· SoapUI tool automatically generates SOAP message after interpreting WSDL file.

Below are the different properties of asserting in SOAPUI

ASSERTION: Is nothing but check points.

We add assertions for each step of the Test Case by clicking Add Assertion button

XPATH MATCH: Uses XPATH expression to select target nodes & its values. XPATH is an XML query language for selecting nodes from an XML document.

Under XPATH window we have to declare namespace which is done by clicking Declare button, below is the namespace which will be automatically added

declare namespace soap='http://schemas.xmlsoap.org/soap/envelope/';

declare namespace ns1='http://tempuri.org/';

1^st Namespace is schema URL and

2^nd corresponds to actual Web Service URL

Below these namespace, we need to add our XPATH which we are validating.

It has count()

exists()

match(xpath/text(), tr)

content – xpath/text()

XQUERY ASSERTION:

It helps us to validate group of XML response which are repetitive in nature.

By XPATH we can only validate one occurrence of XML element but by using XQUERY we can validate group of XML responses.

CONTAINS: searches for the existence of the specified string. It supports regular expression

NOT CONTAINS:

NOT CONTAINS:Searches for non-existence of the specified string. It also supports regular expression

PROPERTIES:

Are nothing but variable declaration at different levels (Project level, TestSuite level, TestCase level). These properties can be defined under custom properties tab.

Project Level properties can be accessible to all the test suites & test cases which is nothing but global availability.

TestSuite Level properties are available to all the test cases which are defined under that test suite.

TestCase Level properties are available to only that particular test case.

Syntax: {#level#propertyName}

Eg: {#project#fromCurrency}

Sample NameSpace declaration inside assertion

declare namespace soapenv='http://schemas.xmlsoap.org/soap/envelope/';

declare namespace ns1='http://tempuri.org/';

//ns1:AddResponse/ns1:AddResult

Property Transfer are used to transfer properties from testStep and their containing testCase, testSuite & project.

Conditional GoTo is used when we want to move to next step only when condition passes, otherwise fail it.

Groovy Scripting:

Groovy scripting is a dynamic language for Java Virtual Machine

Groovy scripting is also known as loosely coupled language.

We can write groovy script under SoapUI Project à TestSuite à TestCase à Add Test Step à Groovy Script à

To comment we use double slash “//”

To print output to console log.info “your message to print to console”

To declare variable def Name = “Kareem”

Note: here def indicates any data type, Name indicates variable and its value inside “”

We can print variable while printing ur message as follows

Log.info “your name is:” + Name

(Or)

Log.info “your name is$ Name”

Loops in Groovy

If(Name== ”kareem”){

Log.info “he is good boy”

}

Else

{

Log.info “he is bad boy”

}

Assert Command

Assert command will check if the condition is true or not, if true it proceeds further step execution, if false it halts/terminates the execution

Syntax : assert variableName == “khan”

For Loop

We can also use def in place of int

for(def i=0; i<=0;i++){

log.info i

}

While Loop

def j=1

while(j<=5){

log.info j

j++

}

Arrays

def abc = new string[5]

abc[0]=”a”

abc[1]=”b”

abc[2]=”c”

abc[3]=”d”

abc[4]=”e”

for(def a=0; a<5;a++){

log.info abc[a];

}

We can get size of an array as abc.size()

We can also declare & initialize array as follows

def terms = [“first0”, “first1”, “first2”, “first3”, “first4”, “first5”]

Exceptions

Which is nothing but abnormal condition which will occur during normal execution?

Have try/catch block

Try{

// add statements which will produce abnormal condition

}

Catch(Exception e){

// printstackTrace of exception logs

}

Data Structures

ArrayList --Index starts from 0

ArrayList ar = new ArrayList();

ar.add(“a”); //to add values to ArrayList

ar.get(0); // to retrieve values from ArrayList

ar.size()//to get size of ArrayList

HashTable

Is a key-value pair

HashTable ht = new HashTable();

ht.put(“Name”,”kareem”);

ht.put(“age”,”27”);

ht.get(“age”);

HashMap

Is a key-value pair

def names = [“Name” : “kareem”, “age”:”27”];

log.info names[“Name”] // key should be passed as argument for hashMap

List

Index starts from 0

def course = [ 1,2,3,”abcString”, 90, “secondString”]

log.info course[3] // will print abcString as output.

When we launch Groovy Script window, we have context & testRunner variable

Scope of context Variable lies in the test case level only.

Context.setProperty(“VariableToStore”,”valueAssignedToVariable”);//to set/add property

Context.getProperty(“VariableName”);//to get property by passing variableName

We can also get custom property values into Groovy Script by using the expand() method as

By using expand() we can get request/response

Log.info Context.expand(‘${#TestCase#Age}’)

#TestCase#Age à 1^st need to specify level from where you are getting value, 2^nd is attribute from which value is read

This Context variable can be used within the TestCase, but not outside the TestCase.

Either it can be request or response.

Eg:

log.info context.expand('${GetSupplierByCity#response}')

GetSupplierByCity – is response output

Response is what we want to print as ouput.

If you want to get only the tagName value from entire response, then we can get as follows.

To do so, we have to import the xml package and then do the operations

import com.eviware.soapui.support.XmlHolder

def response = context.expand('${Add#response}')

log.info response

def xml = new XmlHolder(response)

def desiredValue = xml.getNodeValue("//AddResult")

log.info desiredValue

To set value for any node then we have method inside XmlHolder as follows

Xml.setNodeValue(“//NodeName”,”valueToSet”);

TestRunner scope is in the entire project.

Either we can set/get the property values throughout the Project (May be under different TestSuites/TestCases). This operation we cannot do using Context variable.

If we have global property defined under TestSuite level we can get that under any test case step by using TestRunner as follows under Groovy Script

PreCondition: Create a global property under test suite level “place:Bangalore”

To access the global property under test case step

testRunner.testCase.testSuite.getPropertyValue(“place”)

Above command displays “Bangalore” as value which is assigned to place property

Have to import package

import com.eviware.soapui.impl.wsdl.testcase.WsdlTestRunContext

def desiredTestStep = testRunner.testCase.testSteps(“DeleteEmployee”).setPropertyValue(“Request”, dxml)

desiredStep.run(testRunner, context) // if you want to run the above step we have to use run() method

1^st arg – is testRunner

2^nd arg- is context

Accessing other property values which are located in different testSuite level

myProject=testRunner.testCase.testSuite.project

myProject.testSuites[“Test Suite 2”].testCases[“Test Case 1”].testSteps[“AddEmployee”]

testRunner.testCase.testSuite.project. testSuites[“Test Suite 2”].testCases[“Test Case 1”].testSteps[“AddEmployee”]

If you have to choose one among the multiple testSuites or testCases then we have to select as above within square brackets.

myProject=testRunner.testCase.testSuite.project

desiredTestStep= myProject.testSuites[“Test Suite 2”].testCases[“Test Case 1”].testSteps[“AddEmployee”]

desiredContext=new WsdlTestRunContext(desiredTestStep)

desiredTestStep.run(testRunner, desiredContext)

Assignment:

Execute the Add employee from other test suite and take the same name from request xml

Pass it into get employee details and run the request.

From the response Get employee details take again the name and pass it into delete employee request and run it

SOAPUI PRO Options:

1. To read data/properties from any external sources (excel or xml) pro version has test step called DataSource & DataSourceLoop

DataSource is linked to DataSourceLoop.

For ex: if you want to add employees which are declared inside any external file into database, then we can make use of single script (business logic) and DataSourceLoop so that one by one employee will be added into db taking values from DataSource.

Here DataSourceLoop is nothing but looping operation of DataSource properties

DataSource can be of any one of the following

i. Grid

ii. Excel (Should save excel in .xls format, not in .xlsx format as it wont support)

iii. JDBC

iv. XML

v. Groovy

vi. File

vii. Directory

1. Grid – first Add properties like Name, Age, Dept, ID, Verification by clicking + icon, then provide values in right pane as in screenshot. Then click on Execute button

File – first add all properties, then provide values in excel sheet and save it with .xls format as SaopUI supports only this format.

Select DataSource as Excel à provide excel source à worksheetName & starting Cell

Then click on Execute button

2. Data Sink

If you want to update external file with response results, then we have to go for DataSink.

To write back value of the response into Output property, we have to create Property Transfer request from request as follows

Now export result to external excel file as follows

Same scenario using notepad files as follows

3. Conditional Go to

Is nothing but a condition or if else loop,

If particular property/element is present, then only execute Target Step, if not terminate the execution

4. Delay

To sleep for so many particular of milli seconds before executing further step.

5. DataGen

If you want to generate/pick random numbers then go for this Data Generator.

Data Gen using “Number” type – you can use this for random number generation

Data Gen using “Template” type – you can use this for concatenation

This is not much useful

6. TestCase Debugging – to debug test cases by having breakpoints as in screenshot

Asterisk here indicates change in the value when compares with previous run.

7. Test Case Coverage – will tell you how much coverage are we covering in out testScripts from WSDL file

To get coverage, we have to Enable Coverage and run

8. Test On Demand – by using this we can run our webService from different global location with condition that no files are kept locally. Result of script which ran in Chicago Illinois environment is as below

Happie Learning...!!!

Introduction to WebServices

noreply@blogger.com (kareem) — Mon, 18 Dec 2017 03:28:00 -0800

What is a WebService?

Definition: Web Service is an application/business logic that is accessible using standard internet protocols via standardized XML messaging system.

· Web services are communicated using XML's bcoz these XML's are language/platform independent.

· Integration of heterogeneous applications is possible using Web Services mechanism.

· Web Service allows you to expose the functionality of your existing code over the network. Once it is exposed to the network, other applications can use the functionality of your code.

· Here XML messaging system indicate – request & response

· Bcoz all communications are via XML’s, web services are not dependent on any platform (Operating System) or programming language.

· There are some specific standards to exchange information b/w web services

SOAP is a XML-based protocol which is responsible for exchanging information b/w web services.

SOAP acronym – Simple Object Access Protocol.

· SOAP request are sent via HTTP & SOAP responses are returned within the content of the HTTP response

· Basic web Services communication platform is XML + HTTP

For Eg: Consider 2 applications A (Employee) & B (Third party to verify blacklisted employees). A built on java, B built on Dot net.

App A forms SOAP request bundling all employee details into it and sends over HTTP to App B.

Upon receiving at App B, it un-bundles into its own understanding language, process the request and bundles the response in SOAP format and send it to App A, Again App A unpacks the SOAP message to obtain the results of the request sent

What is WSDL file?

Full form of WSDL is Web Service Description Language

Definition: WSDL describes how to access a web service and what operations it will perform

What are the arguments to pass to invoke particular operations?

What type of data type arguments should pass for the arguments?

What kind of Transport protocol to invoke web service

Tags inside WSDL File:

wsdl:definitions – defines name of the web service, All other tags which are below are under this tag. WSDL is an XML document with <wsdl:definitions> as root element for all elements

wsdl:types – this defines data types that are used in web service

wsdl:message – this describes how data being exchanged b/w the web services providers & Consumers. Each web service has 2 messages: input & output.

wsdl:portType – can combine one request & one response into single request/response operation. This is most commonly used in SOAP services. A portType can have multiple operations.

This element has i/p & o/p messages, and each message has name of type tag and in-turn this type tag has data type information of arguments.

wsdl:binding – provides specific details on how portType operation actually be transmitted over the wire. This binding can be made available via multiple transports including HTTP GET, HTTP POST or SOAP.

wsdl:service – defines where to send the service call (destination web service)

What is SOAP ?
Full form of SOAP is Simple Object Access Protocol

SOAP is XML-based protocol for exchanging information b/w web services.

It enables client applications to easily connect remote services and invoke remote methods.

SOAP provides data transport for web services and it is a communication protocol

What is SOAP Message?

A SOAP message is an ordinary XML document which has following elements.

Envelope (Mandatory): The SOAP envelope tag indicates the start & end of the message so that the receiver knows the entire message has been received.

Every SOAP message has Envelope as root element.

Envelope element is mandatory for a SOAP message

Header (Optional): Headers are optional attributes of the message used in processing the message. These are intended to add new features & functionality.

Body (Mandatory): This consists of application defined XML data being exchanged in the SOAP message.

Fault (Optional): When an error occurs during processing, the response to a SOAP message is SOAP fault element in the body of the message and the fault is returned to the sender of the SOAP message.

Example SOAP message:

Calculator Add Operation SOAP request

<soap:Envelope xmlns:soap=”http://www.w3.org/2003/05/soap-envelope” xmlns:tem=”http://tempuri.org/”>

<soap:Header/>

<soap:Body>

<tem:Add>

<tem:a>3</tem:a>

<tem:b>4</tem:b>

</tem:Add>

</soap:Body>

</soap:Envelope>

Other SOAP example webservices for your practice.

Example Web Services for practice

http://www.webservicex.com/CurrencyConvertor.asmx?wsdl

http://www.dneonline.com/calculator.asmx?WSDL

http://wsf.cdyne.com/WeatherWS/Weather.asmx?WSDL

http://webservices.amazon.com/AWSECommerceService/AWSECommerceService.wsdl

http://www.webservicex.net/country.asmx?WSDL

How to Generate Reports using JUnit + Ant

noreply@blogger.com (kareem) — Wed, 25 Apr 2012 01:52:00 -0700

Generating reports using Ant. Follow the below steps

1. Create 2-3 test cases
Testcase1.java
Testcase2.java
2. Create a test suite as follows

package testcases;

import org.junit.runner.RunWith;
import org.junit.runners.Suite;
import org.junit.runners.Suite.SuiteClasses;

@RunWith(Suite.class)
@SuiteClasses({
Testcase1.class,
Testcase2.class,
})
public class FooterLinks_Suite {
}

3. Check whether the above test suite is running successfully. If ran successfully then do the following
right click on the project root folder --> Export --> General --> Ant Buildfiles --> select the project --> click on Finish
Below is the image representation for clear understanding.

4. This will create build.xml file

5. right click on build.xml file --> select "2 Ant Build"

Select build, testcases, junitreport checkboxes

6.Click on Run after Editing configuration.

7. Build Successful message as follows

8. After Build is Successfull, then a folder with "junit" will be created under root project.

9. Click on junit folder created, it will show respective html files

10. Double click on index.html file, which will display as below.

How to handle logging in Selenium RC

noreply@blogger.com (kareem) — Tue, 17 Apr 2012 09:21:00 -0700

Main thing while automating your application is Logging and Report Generation.
Below is the process how to implement logging with log4j.jar

Follow the steps
1. Go to apache site http://logging.apache.org/log4j/1.2/download.html and download log4j-1.2.16.jar file
2. Under Eclipse create a java class with name Log4jXmlTest
and paste the following code

import com.thoughtworks.selenium.*;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.openqa.selenium.server.SeleniumServer;
import org.apache.log4j.Logger;
import org.apache.log4j.xml.DOMConfigurator;

public class Log4jXmlTest extends SeleneseTestCase {
SeleniumServer seleniumserver;

private static Logger Log = Logger.getLogger(Log4jXmlTest.class.getName());

@Before
public void setUp() throws Exception {
try{
seleniumserver = new SeleniumServer();
seleniumserver.start();
int i = seleniumserver.getPort();
System.out.println("Selenium Running on Port:"+i);

}
catch(Exception e){
e.printStackTrace();
}

DOMConfigurator.configure("log4j.xml");
Log.info("______________________________________________________________");
Log.info("Initializing Selenium...");
selenium = new DefaultSelenium("localhost", 4444, "*chrome", "http://www.google.co.in/");
selenium.start();
Log.info("Selenium instance started");
}

@Test
public void testAdvancedSearch() throws Exception {
Log.info("Opening Google Website");
selenium.open("http://www.google.com/");
Log.info("Clicking on advanced search link");
selenium.click("link=Advanced search");
selenium.waitForPageToLoad("30000");
Log.info("Entering search terms");
selenium.type("as_q", "selenium,selftechy");
Log.info("Clicking on Advanced Search button");
selenium.click("//input[@value='Advanced Search']");
selenium.waitForPageToLoad("30000");
}

@After
public void tearDown() throws Exception {
Log.info("Stopping Selenium...");
Log.info("______________________________________________________________");
selenium.stop();
}

}

3. Again Create .xml file with name log4j.xml and paste the following

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" debug="false">
<appender name="fileAppender" class="org.apache.log4j.FileAppender">
<param name="Threshold" value="INFO" />
<param name="File" value="logfile.log"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d %-5p [%c{1}] %m %n" />
</layout>
</appender>
<root>
<level value="INFO"/>
<appender-ref ref="fileAppender"/>
</root>
</log4j:configuration>

Note: While doing copy paste, be careful that double quotes will be in some other format. So after pasting the code verify once that it should not throw any error.

4. Place the xml file created above in the project root folder.
To place the xml file in root folder do the following
Go to your main project name in eclipse and right click and select --> Properties
You will see the Location under Resources link from the Properties window
Go to that folder and paste the xml file
4. Run the Log4jXmlTest java file
5. After successful running of java class, xml file create logfile.log file which will have the logs.

It will create logfile.log text file under root directory of the project if you manually go to the specified directory. Here is the log file which if you follow the above steps

2012-04-17 19:54:43,627 INFO [Log4jXmlTest] ______________________________________________________________
2012-04-17 19:54:43,627 INFO [Log4jXmlTest] Initializing Selenium...
2012-04-17 19:54:43,752 INFO [Credential] Checking Resource aliases
2012-04-17 19:54:43,768 INFO [SeleniumDriverResourceHandler] Command request: getNewBrowserSession[*chrome, http://www.google.co.in/, ] on session null
2012-04-17 19:54:43,783 INFO [BrowserSessionFactory] creating new remote session
2012-04-17 19:54:43,971 INFO [BrowserSessionFactory] Allocated session cc6ea8df996c412e8aca55f3d9d56080 for http://www.google.co.in/, launching...
2012-04-17 19:54:44,221 INFO [FirefoxChromeLauncher] Preparing Firefox profile...
2012-04-17 19:54:47,377 INFO [FirefoxChromeLauncher] Launching Firefox...
2012-04-17 19:54:52,299 INFO [SeleniumDriverResourceHandler] Got result: OK,cc6ea8df996c412e8aca55f3d9d56080 on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:54:52,299 INFO [Log4jXmlTest] Selenium instance started
2012-04-17 19:54:52,299 INFO [Log4jXmlTest] Opening Google Website
2012-04-17 19:54:52,299 INFO [SeleniumDriverResourceHandler] Command request: open[http://www.google.com/, ] on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:54:52,299 WARN [SeleniumDriverResourceHandler] you appear to be changing domains from http://www.google.co.in/ to http://www.google.com/
this may lead to a 'Permission denied' from the browser (unless it is running as *iehta or *chrome,
or alternatively the selenium server is running in proxy injection mode)
2012-04-17 19:54:57,298 INFO [SeleniumDriverResourceHandler] Got result: OK on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:54:57,298 INFO [Log4jXmlTest] Clicking on advanced search link
2012-04-17 19:54:57,298 INFO [SeleniumDriverResourceHandler] Command request: click[link=Advanced search, ] on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:54:57,361 INFO [SeleniumDriverResourceHandler] Got result: OK on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:54:57,361 INFO [SeleniumDriverResourceHandler] Command request: waitForPageToLoad[30000, ] on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:54:59,298 INFO [SeleniumDriverResourceHandler] Got result: OK on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:54:59,298 INFO [Log4jXmlTest] Entering search terms
2012-04-17 19:54:59,298 INFO [SeleniumDriverResourceHandler] Command request: type[as_q, selenium,selftechy] on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:54:59,470 INFO [SeleniumDriverResourceHandler] Got result: OK on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:54:59,470 INFO [Log4jXmlTest] Clicking on Advanced Search button
2012-04-17 19:54:59,470 INFO [SeleniumDriverResourceHandler] Command request: click[//input[@value='Advanced Search'], ] on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:54:59,580 INFO [SeleniumDriverResourceHandler] Got result: OK on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:54:59,580 INFO [SeleniumDriverResourceHandler] Command request: waitForPageToLoad[30000, ] on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:55:02,486 INFO [SeleniumDriverResourceHandler] Got result: OK on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:55:02,486 INFO [Log4jXmlTest] Stopping Selenium...
2012-04-17 19:55:02,486 INFO [Log4jXmlTest] ______________________________________________________________
2012-04-17 19:55:02,486 INFO [SeleniumDriverResourceHandler] Command request: testComplete[, ] on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:55:02,486 INFO [FirefoxChromeLauncher] Killing Firefox...
2012-04-17 19:55:02,861 INFO [SeleniumDriverResourceHandler] Got result: OK on session cc6ea8df996c412e8aca55f3d9d56080
2012-04-17 19:55:02,876 INFO [SeleniumServer] Shutting down...
2012-04-17 19:55:02,876 INFO [ThreadedServer] Stopping Acceptor ServerSocket[addr=0.0.0.0/0.0.0.0,port=0,localport=4444]
2012-04-17 19:55:02,986 INFO [SocketListener] Stopped SocketListener on 0.0.0.0:4444
2012-04-17 19:55:03,033 INFO [Container] Stopped HttpContext[/selenium-server/driver,/selenium-server/driver]
2012-04-17 19:55:03,095 INFO [Container] Stopped HttpContext[/selenium-server,/selenium-server]
2012-04-17 19:55:03,142 INFO [Container] Stopped HttpContext[/,/]
2012-04-17 19:55:03,142 INFO [Container] Stopped org.openqa.jetty.jetty.servlet.ServletHandler@1befab0
2012-04-17 19:55:03,204 INFO [Container] Stopped HttpContext[/wd,/wd]
2012-04-17 19:55:03,204 INFO [Container] Stopped org.openqa.jetty.jetty.Server@1f20eeb

How to Upload / Attach any file or document with Selenium RC

noreply@blogger.com (kareem) — Tue, 17 Apr 2012 06:06:00 -0700

Steps that need to follow
1. In order to upload files we need to have AutoIT (freeware BASIC-like scripting language designed for automating the Windows GUI -- keystrokes, mouse actions ).
2. Download AutoIT software from http://www.autoitscript.com/site/autoit/downloads/
3. Install upon clicking the downloaded AutoIT.exe file
4. If you want to upload a file into your application/system, create a document (Ex: lets say uploadFile.doc )
5. Next step is go to any folder in your drive and right click --> New --> AutoIT v3 Script and select script.
6. It will open up AutoIT v3 script file, enter the following code at last and save the file as if you save any document with some name (Ex: lets say attachDocScript.au3 )

WinWaitActive("Choose File")
Send("C:\Program Files\AutoIt3\uploadFile.doc") // specify your own path where attaching document is located.
Send("{ENTER}")

7. Close the AutoIT script file and right click on this, select compile the script -- which generates .exe file of the same. (Ex: attachDocScript.exe )
8. In your selenium program enter the following code after clicking the attach button from your application.

try {
String[] commands = new String[]{};
commands = new String[]{"C:\\Program Files\\AutoIt3\\attachDocScript.exe"}; //location of the autoit executable
Runtime.getRuntime().exec(commands);
}
catch (IOException e) {}

9. Now run your progam. you Can see that you uploaded the document in your application successfully.

write the selenium output result into a document instead of console

noreply@blogger.com (kareem) — Tue, 17 Apr 2012 06:04:00 -0700

If you want to display all the links into a text file or word document then you can do as follows
1. We have getAllLinks() in selenium which will prints all links to the console output.

selenium.getAllLinks();

2. Instantiate FileWriter and BufferedWriter from java.io package.
4. If need to write the output into a text file then store all links into an String array as follows

String alllinks [] = selenium.getAllLinks();

5. Use "for loop" to write the values into file with help of BufferedWriter object.

System.out.println("Get All Links");
String alllinks [] = selenium.getAllLinks();

FileWriter fileWriter2 = new FileWriter("D:\\allLinks.doc");
BufferedWriter bufferedWriter2 = new BufferedWriter(fileWriter2);
bufferedWriter2.write("Get All Links");
for(int c=0; c<alllinks.length; c++){

bufferedWriter2.write(alllinks[c]);
bufferedWriter2.newLine();
System.out.println("\n");
} bufferedWriter2.close();

Java Interview Questions and Answers1

noreply@blogger.com (kareem) — Thu, 3 Nov 2011 04:00:00 -0700

What if the main method is declared as private?

The program compiles properly but at runtime it will give “Main method not public.” message.

What is meant by pass by reference and pass by value in Java?

Pass by reference means, passing the address itself rather than passing the value. Pass by value means passing a copy of the value.

What is Byte Code?

What gives java it’s “write once and run anywhere” nature?

All Java programs are compiled into class files that contain bytecodes. These byte codes can be run in any platform and hence java is said to be platform independent.

Expain the reason for each keyword of public static void main(String args[])?

public- main(..) is the first method called by java environment when a program is executed so it has to accessible from java environment. Hence the access specifier has to be public.

static: Java environment should be able to call this method without creating an instance of the class , so this method must be declared as static.

void: main does not return anything so the return type must be void

The argument String indicates the argument type which is given at the command line and arg is an array for string given during command line.

What are the differences between == and .equals() ?

what is difference between == and equals

Difference between == and equals method

What would you use to compare two String variables – the operator == or the method equals()?

How is it possible for two String objects with identical values not to be equal under the == operator?

The == operator compares two objects to determine if they are the same object in memory i.e. present in the same memory location. It is possible for two String objects to have the same value, but located in different areas of memory.

== compares references while .equals compares contents. The method public boolean equals(Object obj) is provided by the Object class and can be overridden. The default implementation returns true only if the object is compared with itself, which is equivalent to the equality operator == being used to compare aliases to the object. String, BitSet, Date, and File override the equals() method. For two String objects, value equality means that they contain the same character sequence. For the Wrapper classes, value equality means that the primitive values are equal.

public class EqualsTest {

public static void main(String[] args) {

String s1 = "abc";

String s2 = s1;

String s5 = "abc";

String s3 = new String("abc");

String s4 = new String("abc");

System.out.println("== comparison : " + (s1 == s5));

System.out.println("== comparison : " + (s1 == s2));

System.out.println("Using equals method : " + s1.equals(s2));

System.out.println("== comparison : " + s3 == s4);

System.out.println("Using equals method : " + s3.equals(s4));

}

Output
== comparison : true
== comparison : true
Using equals method : true
== comparison : false
Using equals method : true

What if the static modifier is removed from the signature of the main method?

What if I do not provide the String array as the argument to the method?

Program compiles. But at runtime throws an error “NoSuchMethodError”.

Why oracle Type 4 driver is named as oracle thin driver?

Oracle provides a Type 4 JDBC driver, referred to as the Oracle “thin” driver. This driver includes its own implementation of a TCP/IP version of Oracle’s Net8 written entirely in Java, so it is platform independent, can be downloaded to a browser at runtime, and does not require any Oracle software on the client side. This driver requires a TCP/IP listener on the server side, and the client connection string uses the TCP/IP port address, not the TNSNAMES entry for the database name.

What is the difference between final, finally and finalize? What do you understand by the java final keyword?

What is final, finalize() and finally?

What is finalize() method?

What is the difference between final, finally and finalize?

What does it mean that a class or member is final?

o final – declare constant
o finally – handles exception
o finalize – helps in garbage collection

Variables defined in an interface are implicitly final. A final class can’t be extended i.e., final class may not be subclassed. This is done for security reasons with basic classes like String and Integer. It also allows the compiler to make some optimizations, and makes thread safety a little easier to achieve. A final method can’t be overridden when its class is inherited. You can’t change value of a final variable (is a constant). finalize() method is used just before an object is destroyed and garbage collected. finally, a key word used in exception handling and will be executed whether or not an exception is thrown. For example, closing of open connections is done in the finally method.

What is the Java API?

The Java API is a large collection of ready-made software components that provide many useful capabilities, such as graphical user interface (GUI) widgets.

What is the GregorianCalendar class?

The GregorianCalendar provides support for traditional Western calendars.

What is the ResourceBundle class?

The ResourceBundle class is used to store locale-specific resources that can be loaded by a program to tailor the program’s appearance to the particular locale in which it is being run.

Why there are no global variables in Java?

Global variables are globally accessible. Java does not support globally accessible variables due to following reasons:

The global variables breaks the referential transparency
Global variables creates collisions in namespace.

How to convert String to Number in java program?

The valueOf() function of Integer class is is used to convert string to Number. Here is the code example:
String numString = “1000″;
int id=Integer.valueOf(numString).intValue();

What is the difference between a while statement and a do statement?

A while statement (pre test) checks at the beginning of a loop to see whether the next loop iteration should occur. A do while statement (post test) checks at the end of a loop to see whether the next iteration of a loop should occur. The do statement will always execute the loop body at least once.

Describe the principles of OOPS.

There are three main principals of oops which are called Polymorphism, Inheritance and Encapsulation.

Explain the Inheritance principle.

Inheritance is the process by which one object acquires the properties of another object. Inheritance allows well-tested procedures to be reused and enables changes to make once and have effect in all relevant places

What is implicit casting?

Implicit casting is the process of simply assigning one entity to another without any transformation guidance to the compiler. This type of casting is not permitted in all kinds of transformations and may not work for all scenarios.

Example

int i = 1000;

long j = i; //Implicit casting

Is sizeof a keyword in java?

The sizeof operator is not a keyword.

In System.out.println(), what is System, out and println?

System is a predefined final class, out is a PrintStream object and println is a built-in overloaded method in the out object.

What are Encapsulation, Inheritance and Polymorphism

Explain the Polymorphism principle. Explain the different forms of Polymorphism.

Polymorphism in simple terms means one name many forms. Polymorphism enables one entity to be used as a general category for different types of actions. The specific action is determined by the exact nature of the situation.

Polymorphism exists in three distinct forms in Java:
• Method overloading
• Method overriding through inheritance
• Method overriding through the Java interface

What is explicit casting?

Explicit casting in the process in which the complier are specifically informed to about transforming the object.

Example

long i = 700.20;

int j = (int) i; //Explicit casting

What is the Java Virtual Machine (JVM)?

The Java Virtual Machine is software that can be ported onto various hardware-based platforms

What do you understand by downcasting?

The process of Downcasting refers to the casting from a general to a more specific type, i.e. casting down the hierarchy

What are Java Access Specifiers?

What is the difference between public, private, protected and default Access Specifiers?

What are different types of access modifiers?

Access specifiers are keywords that determine the type of access to the member of a class. These keywords are for allowing
privileges to parts of a program such as functions and variables. These are:
• Public : accessible to all classes
• Protected : accessible to the classes within the same package and any subclasses.
• Private : accessible only to the class to which they belong
• Default : accessible to the class to which they belong and to subclasses within the same package

Which class is the superclass of every class?

Object.

Name primitive Java types.

The 8 primitive types are byte, char, short, int, long, float, double, and boolean.

What is the difference between static and non-static variables?

What are class variables?

What is static in java?

What is a static method?

A static variable is associated with the class as a whole rather than with specific instances of a class. Each object will share a common copy of the static variables i.e. there is only one copy per class, no matter how many objects are created from it. Class variables or static variables are declared with the static keyword in a class. These are declared outside a class and stored in static memory. Class variables are mostly used for constants. Static variables are always called by the class name. This variable is created when the program starts and gets destroyed when the programs stops. The scope of the class variable is same an instance variable. Its initial value is same as instance variable and gets a default value when its not initialized corresponding to the data type. Similarly, a static method is a method that belongs to the class rather than any object of the class and doesn’t apply to an object or even require that any objects of the class have been instantiated.
Static methods are implicitly final, because overriding is done based on the type of the object, and static methods are attached to a class, not an object. A static method in a superclass can be shadowed by another static method in a subclass, as long as the original method was not declared final. However, you can’t override a static method with a non-static method. In other words, you can’t change a static method into an instance method in a subclass.

Non-static variables take on unique values with each object instance.

How does Java handle integer overflows and underflows?

It uses those low order bytes of the result that can fit into the size of the type allowed by the operation.

What if I write static public void instead of public static void?

Program compiles and runs properly.

What is the difference between declaring a variable and defining a variable?

In declaration we only mention the type of the variable and its name without initializing it. Defining means declaration + initialization. E.g. String s; is just a declaration while String s = new String (“bob”); Or String s = “bob”; are both definitions.

What type of parameter passing does Java support?

In Java the arguments (primitives and objects) are always passed by value. With objects, the object reference itself is passed by value and so both the original reference and parameter copy both refer to the same object.

Explain the Encapsulation principle.

Encapsulation is a process of binding or wrapping the data and the codes that operates on the data into a single entity. This keeps the data safe from outside interface and misuse. Objects allow procedures to be encapsulated with their data to reduce potential interference. One way to think about encapsulation is as a protective wrapper that prevents code and data from being arbitrarily accessed by other code defined outside the wrapper.

What do you understand by a variable?

Variable is a named memory location that can be easily referred in the program. The variable is used to hold the data and it can be changed during the course of the execution of the program.

What do you understand by casting in java language? What are the types of casting?

The process of converting one data type to another is called Casting. There are two types of casting in Java; these are implicit casting and explicit casting.

What is the first argument of the String array in main method?

The String array is empty. It does not have any element. This is unlike C/C++ where the first element by default is the program name. If we do not provide any arguments on the command line, then the String array of main method will be empty but not null.

How can one prove that the array is not null but empty?

Print array.length. It will print 0. That means it is empty. But if it would have been null then it would have thrown a NullPointerException on attempting to print array.length.

Can an application have multiple classes having main method?

Yes. While starting the application we mention the class name to be run. The JVM will look for the main method only in the class whose name you have mentioned. Hence there is not conflict amongst the multiple classes having main method.

When is static variable loaded? Is it at compile time or runtime? When exactly a static block is loaded in Java?

Static variable are loaded when classloader brings the class to the JVM. It is not necessary that an object has to be created. Static variables will be allocated memory space when they have been loaded. The code in a static block is loaded/executed only once i.e. when the class is first initialized. A class can have any number of static blocks. Static block is not member of a class, they do not have a return statement and they cannot be called directly. Cannot contain this or super. They are primarily used to initialize static fields.

Can I have multiple main methods in the same class?

We can have multiple overloaded main methods but there can be only one main method with the following signature :

public static void main(String[] args) {}

No the program fails to compile. The compiler says that the main method is already defined in the class.

Explain working of Java Virtual Machine (JVM)?

JVM is an abstract computing machine like any other real computing machine which first converts .java file into .class file by using Compiler (.class is nothing but byte code file.) and Interpreter reads byte codes.

How can I swap two variables without using a third variable?

Add two variables and assign the value into First variable. Subtract the Second value with the result Value. and assign to Second variable. Subtract the Result of First Variable With Result of Second Variable and Assign to First Variable. Example:

int a=5,b=10;a=a+b; b=a-b; a=a-b;

An other approach to the same question

You use an XOR swap.

for example:

int a = 5; int b = 10;
a = a ^ b;
b = a ^ b;
a = a ^ b;

What is data encapsulation?

Encapsulation may be used by creating ‘get’ and ‘set’ methods in a class (JAVABEAN) which are used to access the fields of the object. Typically the fields are made private while the get and set methods are public. Encapsulation can be used to validate the data that is to be stored, to do calculations on data that is stored in a field or fields, or for use in introspection (often the case when using javabeans in Struts, for instance). Wrapping of data and function into a single unit is called as data encapsulation. Encapsulation is nothing but wrapping up the data and associated methods into a single unit in such a way that data can be accessed with the help of associated methods. Encapsulation provides data security. It is nothing but data hiding.

What is reflection API? How are they implemented?

Reflection is the process of introspecting the features and state of a class at runtime and dynamically manipulate at run time. This is supported using Reflection API with built-in classes like Class, Method, Fields, Constructors etc. Example: Using Java Reflection API we can get the class name, by using the getName method.

Does JVM maintain a cache by itself? Does the JVM allocate objects in heap? Is this the OS heap or the heap maintained by the JVM? Why

Yes, the JVM maintains a cache by itself. It creates the Objects on the HEAP, but references to those objects are on the STACK.

Can a method be static and synchronized?

A static method can be synchronized. If you do so, the JVM will obtain a lock on the java.lang.
Class instance associated with the object. It is similar to saying:

synchronized(XYZ.class) {

}

What is difference between String and StringTokenizer?

A StringTokenizer is utility class used to break up string.

Example:

StringTokenizer st = new StringTokenizer(“Hello World”);

while (st.hasMoreTokens()) {

System.out.println(st.nextToken());

}

Output:

Hello

World

SQL Interview Question and Answers for Beginners

noreply@blogger.com (kareem) — Mon, 31 Oct 2011 07:47:00 -0700

What the difference between UNION and UNIONALL?

Union will remove the duplicate rows from the result set while Union all does'nt.

What is the difference between TRUNCATE and DELETE commands?

Both will result in deleting all the rows in the table .TRUNCATE call cannot be rolled back as it is a DDL command and all memory space for that table is released back to the server. TRUNCATE is much faster.Whereas DELETE call is an DML command and can be rolled back.

Which system table contains information on constraints on all the tables created ?
yes,
USER_CONSTRAINTS,
system table contains information on constraints on all the tables created

How to find out the database name from SQL*PLUS command prompt?
Select * from global_name;
This will give the datbase name which u r currently connected to.....

What is the difference between SQL and SQL Server ?

SQLServer is an RDBMS just like oracle,DB2 from Microsoft
whereas
Structured Query Language (SQL), pronounced "sequel", is a language that provides an interface to relational database systems. It was developed by IBM in the 1970s for use in System R. SQL is a de facto standard, as well as an ISO and ANSI standard. SQL is used to perform various operations on RDBMS.

What is diffrence between Co-related sub query and nested sub query?

Correlated subquery runs once for each row selected by the outer query. It contains a reference to a value from the row selected by the outer query.

Nested subquery runs only once for the entire nesting (outer) query. It does not contain any reference to the outer query row.

For example,

Correlated Subquery:

select e1.empname, e1.basicsal, e1.deptno from emp e1 where e1.basicsal = (select max(basicsal) from emp e2 where e2.deptno = e1.deptno)

Nested Subquery:

select empname, basicsal, deptno from emp where (deptno, basicsal) in (select deptno, max(basicsal) from emp group by deptno)

WHAT OPERATOR PERFORMS PATTERN MATCHING?
Pattern matching operator is LIKE and it has to used with two attributes

1. % and

2. _ ( underscore )

% means matches zero or more characters and under score means mathing exactly one character

1)What is difference between Oracle and MS Access?
2) What are disadvantages in Oracle and MS Access?
3) What are feratures&advantages in Oracle and MS Access?
Oracle's features for distributed transactions, materialized views and replication are not available with MS Access. These features enable Oracle to efficiently store data for multinational companies across the globe. Also these features increase scalability of applications based on Oracle.

What is database?
A database is a collection of data that is organized so that itscontents can easily be accessed, managed and updated. open this url : http://www.webopedia.com/TERM/d/database.html

What is cluster.cluster index and non cluster index ?
Clustered Index:- A Clustered index is a special type of index that reorders the way records in the table are physically stored. Therefore table may have only one clustered index.Non-Clustered Index:- A Non-Clustered index is a special type of index in which the logical order of the index does not match the physical stored order of the rows in the disk. The leaf nodes of a non-clustered index does not consists of the data pages. instead the leaf node contains index rows.

How can i hide a particular table name of our schema?
you can hide the table name by creating synonyms.

e.g) you can create a synonym y for table x

create synonym y for x;

What is difference between DBMS and RDBMS?
The main difference of DBMS & RDBMS is

RDBMS have Normalization. Normalization means to refining the redundant and maintain the stablization.
the DBMS hasn't normalization concept.

What are the advantages and disadvantages of primary key and foreign key in SQL?

Primary key

Advantages

1) It is a unique key on which all the other candidate keys are functionally dependent

Disadvantage

1) There can be more than one keys on which all the other attributes are dependent on.

Foreign Key

Advantage

1)It allows refrencing another table using the primary key for the other table

JAVA Interview Questions

noreply@blogger.com (kareem) — Mon, 31 Oct 2011 07:37:00 -0700

JAVA Interview Questions

Question: How could Java classes direct program messages to the system console, but error messages, say to a file?

Answer: The class System has a variable out that represents the standard output, and the variable errthat represents the standard error device. By default, they both point at the system console. This how the standard output could be re-directed:

Stream st = new Stream(new FileOutputStream("output.txt")); System.setErr(st); System.setOut(st);

Question: What's the difference between an interface and an abstract class?

Answer: An abstract class may contain code in method bodies, which is not allowed in an interface. With abstract classes, you have to inherit your class from it and Java does not allow multiple inheritance. On the other hand, you can implement multiple interfaces in your class.

Question: Why would you use a synchronized block vs. synchronized method?

Answer: Synchronized blocks place locks for shorter periods than synchronized methods.

Question: Explain the usage of the keyword transient?

Answer: This keyword indicates that the value of this member variable does not have to be serialized with the object. When the class will be de-serialized, this variable will be initialized with a default value of its data type (i.e. zero for integers).

Question: How can you force garbage collection?

Answer: You can't force GC, but could request it by calling System.gc(). JVM does not guarantee that GC will be started immediately.

Question: How do you know if an explicit object casting is needed?

Answer: If you assign a superclass object to a variable of a subclass's data type, you need to do explicit casting. For example:

Object a; Customer b; b = (Customer) a;

When you assign a subclass to a variable having a supeclass type, the casting is performed automatically.

Question: What's the difference between the methods sleep() and wait()

Answer: The code sleep(1000); puts thread aside for exactly one second. The code wait(1000), causes a wait of up to one second. A thread could stop waiting earlier if it receives the notify() or notifyAll() call. The method wait() is defined in the class Object and the method sleep() is defined in the class Thread.

Question: Can you write a Java class that could be used both as an applet as well as an application?

Answer: Yes. Add a main() method to the applet.

Question: What's the difference between constructors and other methods?

Answer: Constructors must have the same name as the class and can not return a value. They are only called once while regular methods could be called many times.

Question: Can you call one constructor from another if a class has multiple constructors

Answer: Yes. Use this() syntax.

Question: Explain the usage of Java packages.

Answer: This is a way to organize files when a project consists of multiple modules. It also helps resolve naming conflicts when different packages have classes with the same names. Packages access level also allows you to protect data from being used by the non-authorized classes.

Question: If a class is located in a package, what do you need to change in the OS environment to be able to use it?

Answer: You need to add a directory or a jar file that contains the package directories to the CLASSPATH environment variable. Let's say a class Employee belongs to a package com.xyz.hr; and is located in the file c:\dev\com\xyz\hr\Employee.java. In this case, you'd need to add c:\dev to the variable CLASSPATH. If this class contains the method main(), you could test it from a command prompt window as follows:

c:\>java com.xyz.hr.Employee

Question: What's the difference between J2SDK 1.5 and J2SDK 5.0?

Answer: There's no difference, Sun Microsystems just re-branded this version.

Question: What would you use to compare two String variables - the operator == or the method equals()?

Answer: I'd use the method equals() to compare the values of the Strings and the == to check if two variables point at the same instance of a String object.

Question: Does it matter in what order catch statements for FileNotFoundException and IOExceptipon are written?

Answer: Yes, it does. The FileNoFoundException is inherited from the IOException. Exception's subclasses have to be caught first.

Question: Can an inner class declared inside of a method access local variables of this method?

Answer: It's possible if these variables are final.

Question: What can go wrong if you replace && with & in the following code: String a=null; if (a!=null && a.length()>10) {...}

Answer: A single ampersand here would lead to a NullPointerException.

Question: What's the main difference between a Vector and an ArrayList

Answer: Java Vector class is internally synchronized and ArrayList is not.

Question: When should the method invokeLater()be used?

Answer: This method is used to ensure that Swing components are updated through the event-dispatching thread.

Question: How can a subclass call a method or a constructor defined in a superclass?

Answer: Use the following syntax: super.myMethod(); To call a constructor of the superclass, just write super(); in the first line of the subclass's constructor.

Question: When you declare a method as abstract method ?

Answer: When i want child class to implement the behavior of the method.

Question: Can I call a abstract method from a non abstract method ?

Answer: Yes, We can call a abstract method from a Non abstract method in a Java abstract class

Question: What is the difference between an Abstract class and Interface in Java ? or can you explain when you use Abstract classes ?

Answer: Abstract classes let you define some behaviors; they force your subclasses to provide others. These abstract classes will provide the basic funcationality of your applicatoin, child class which inherited this class will provide the funtionality of the abstract methods in abstract class. When base class calls this method, Java calls the method defined by the child class.

An Interface can only declare constants and instance methods, but cannot implement default behavior.
Interfaces provide a form of multiple inheritance. A class can extend only one other class.
Interfaces are limited to public methods and constants with no implementation. Abstract classes can have a partial implementation, protected parts, static methods, etc.
A Class may implement several interfaces. But in case of abstract class, a class may extend only one abstract class.
Interfaces are slow as it requires extra indirection to find corresponding method in the actual class. Abstract classes are fast.

Question: What is user-defined exception in java ?

Answer: User-defined expections are the exceptions defined by the application developer which are errors related to specific application. Application Developer can define the user defined exception by inherite the Exception class as shown below. Using this class we can throw new exceptions.

Java Example : public class noFundException extends Exception { } Throw an exception using a throw statement: public class Fund { ... public Object getFunds() throws noFundException { if (Empty())throw new noFundException(); ... } } User-defined exceptions should usually be checked.

SQL For Beginners

noreply@blogger.com (kareem) — Sat, 29 Oct 2011 22:21:00 -0700

A Database is one which has 1 or more tables.
A Table is the actual data with rows and columns. Table has a unique name. SQL is used to interact with database.

SQL -- Structured Query Language, its not case sensitive.
SQL commands comes under the following catagories

1. DML -- Data Manipulation Language
SELECT - extracts data from a database
UPDATE - updates data in a database
DELETE - deletes data from a database
INSERT INTO - inserts new data into a database

2. DDL -- Data Definitaion Language
CREATE TABLE - creates a new table
ALTER TABLE - modifies a table
DROP TABLE - deletes a table
CREATE INDEX - creates an index (search key)
DROP INDEX - deletes an index

3. DCL -- Data Control Language
GRANT - SQL GRANT is a command used to provide access or privileges on the database objects to the users
REVOKE - command removes user access rights or privileges to the database objects.

4. TCL -- Transactional Control Language
COMMIT - it successfully saves the transaction that we did.
ROLLBACK - is used to revert the transactions that we did before.

SQL COMMANDS

SELECT : -- is used to extract the data from db
Syntax : SELECT colName FROM tableName;

DISTINCT: -- is used to select distinct data from column if any duplicate data exists.
Syntax: SELECT DISTINCT colName FROM tableName;

WHERE: -- is used to extract only those records that fulfill a specified criterion.
Syntax: SELECT colName FROM tableName WHERE colName operator Value;
Operator can be =, <> , >, <, >=, <=, BETWEEN, LIKE, IN ORDER BY: -- is used to sort the result-set by a specified column. Syntax: SELECT colName FROM tableName ORDER BY colName ASC or DESC

INSERT INTO: statement is used to insert a new row in a table. Syntax: INSERT INTO table_name VALUES (value1, value2, value3,...) We can Insert data in specified columns as Eg: INSERT INTO Persons (P_Id, LastName, FirstName) VALUES (5, 'Tjessem', 'Jakob') ;

UPDATE: -- is used to update existing records in a table.
Syntax: UPDATE table_name SET column1=value, column2=value2,... WHERE some_column=some_value

DELETE: is used to delete records / rows in a table.
Syntax: DELETE FROM tableName WHERE colName = othercolName;
To delete all records from a table, then give below command
DELETE * FROM table_name

TOP: TOP clause is used to specify the number of records to return.
Syntax: SELECT TOP number|percent column_name(s) FROM table_name
Eg1 : SELECT TOP 2 * FROM tableName; -- returns top 2 records from table.
Eg2: SELECT TOP 50 PERCENT * FROM tableName; -- returns top 50 % records from table.
Eg3: SELECT * FROM Persons WHERE ROWNUM <=5 -- returns top 5 records from table. (IN ORACLE)
Eg4: SELECT * FROM Persons LIMIT 5 -- returns top 5 records from table. ( IN MYSQL)

LIKE: operator is used to search for a specified pattern in a column.
Syntax: SELECT column_name(s) FROM table_name WHERE column_name LIKE pattern;
Eg1: SELECT empName FROM Employee WHERE empName LIKE 'a%' --- selects employee names starting with a .
Eg2: SELECT empName FROM Employee WHERE empName LIKE '%a' --- selects employee names ending with a .
Eg3: SELECT empName FROM Employee WHERE empName LIKE '%ab%' --- selects employee names which has ab in their names .
Eg4: SELECT empName FROM Employee WHERE empName NOT LIKE 'b%' --- selects employee names which doesn't starts with b.

SQL Wildcards: -- can be used when searching for data in a database.
% -- percentage -- matches zero or more characters
_ -- underscore -- matches exactly one character
Eg: SELECT * FROM Persons WHERE FirstName LIKE '_la' --- this will return matching single character at begining.
[charlist] -- matches with list of characters
Eg: SELECT * FROM Persons WHERE LastName LIKE '[bsp]%'--- this will return LastNames starting with b or s or p.

IN Operator: -- allows you to specify multiple values in a WHERE clause.
Syntax: SELECT column_name(s) FROM table_name WHERE column_name IN (value1,value2,...)
Eg: SELECT LastName FROM Persons WHERE LastName IN ('kareem', 'khan') -- this will select LastName from Persons who have last name as karee and khan.

BETWEEN Operator: -- BETWEEN operator is used in a WHERE clause to select a range of data between two values.
Syntax: SELECT column_name(s) FROM table_name WHERE column_name BETWEEN value1 AND value2
Eg1: SELECT * FROM Persons WHERE LastName BETWEEN 'kareem' AND 'khan' ; -- Selects LastName between kareem and khan.
Eg2: SELECT * FROM Persons WHERE LastName NOT BETWEEN 'kareem' AND 'khan' ; -- Selects all LastName except kareem and khan.

Alias: You can give a table or a column another name by using an alias
Syntax: SELECT column_name(s) FROM table_name AS alias_name --- for tables Syntax: SELECT column_name AS alias_name FROM table_name --- for columns

JOINS: -- are used to extract the data from 2 or more number of tables. While extracting data from different tables, each table will have kyes to relate each other. Primary Key is a column with unique value for each row.There are different types of joins

1. JOIN / INNER JOIN -- Return rows when there is at least one match in both tables
2. LEFT JOIN -- Return all rows from the left table, even if there are no matches in the right table
3. RIGHT JOIN -- Return all rows from the right table, even if there are no matches in the left table
4. FULL JOIN -- Return all rows from left and right tables when there is a match in one of the tables

UNION: -- UNION operator is used to combine the result-set of two or more SELECT statements.

Syntax: SELECT column_name(s) FROM table_name1 UNION SELECT column_name(s) FROM table_name2

Eg: SELECT e_EuroName FROM European UNION SELECT e_INDIA FROM INDIAN --- returns only distinct values, it wont return duplicate values.

Column_name should of same data type and columns should be in same order in the tables on which we perform UNION operation.
Syntax: SELECT column_name(s) FROM table_name1 UNION ALL SELECT column_name(s) FROM table_name2

Eg: SELECT e_EuroName FROM European UNION ALL SELECT e_INDIA FROM INDIAN --- returns all values even if there are mutilple values with same value.

CREATE: -- is used to create a table in a database.

Syntax: CREATE TABLE table_name ( column_name1 data_type, column_name2 data_type, column_name3 data_type, .... )

Eg: CREATE TABLE employee ( EName varchar2(20), EmpID int(5), EmpAddr varchar20(30) )

SQL CONSTRAINTS: -- are used to limit the type of data that can go into a table. These constraints will be given while creating table or after creating tables.
NOT NULL
UNIQUE KEY
PRIMARY KEY
FOREIGN KEY
CHECK
DEFAULT -- are constraints

1. NOT NULL :- By default a table column can hold NULL values. So while creating a table specifying NOT NULL will make users wont accept NULL Values anymore
Eg: CREATE TABLE employee ( EName varchar2(20) NOT NULL, EmpID int(5) NOT NULL, EmpAddr varchar20(30) )

2. UNIQUE :- this constraint uniquely identifies each record in a database table.
UNIQUE and PRIMARY KEY constraints both provide a guarantee for uniqueness for a column or set of columns.
A PRIMARY KEY constraint automatically has a UNIQUE constraint defined on it.
Note that you can have many UNIQUE constraints per table, but only one PRIMARY KEY constraint per table.

Eg: CREATE TABLE employee ( EName varchar2(20) NOT NULL, EmpID int(5) NOT NULL UNIQUE, EmpAddr varchar20(30) )

Whenever a table has been created without unique constraint, then through ALTER command we can create UNIQUE constraint as follows:
Eg: ALTER TABLE employee ADD UNIQUE (EmpID)

If you want to drop unique constraint in the table, then
Eg: ALTER TABLE employee DROP CONSTRAINT EmpID

3. PRIMARY KEY :- uniquely identifies each record in a database table.
Primary keys should contain unique values.
A Primary key column cannot contain NULL values. Each table should have a primary key. and each table can have only one primary key.

Eg: CREATE TABLE persons ( P_Id int NOT NULL, L_name varchar(100) NOT NULL, F_name varchar(100), city varchar(100), PRIMARY_KEY(P_Id) );

If want to ALTER the table then
ALTER TABLE persons ADD PRIMARY KEY (P_Id);
If want to DROP the table then
ALTER TABLE persons DROP PRIMARY KEY;

4. FOREIGN KEY :- is one which points to a PRIMAY KEY in another table.

Eg: CREATE TABLE Orders (O_Id int NOT NULL, OrderNo int NOT NULL, P_Id int, PRIMARY KEY (O_Id), FOREIGN KEY (P_Id) REFERENCES Persons(P_Id));

If we want to ALTER the table
ALTER TABLE Orders ADD FOREIGN KEY (P_Id) REFERENCES Persons(P_Id) ;

If we want to DROP the table
ALTER TABLE Orders DROP FOREIGN KEY fk_PerOrders;

5. CHECK :- is used to limit the value range that can be placed in a column.
If CHECK is defined on a single column, then it allows only certain values for this column.
If CHECK is defined on a table, it can limit the values in certain columns based on values in other columns in the row.

Eg: CREATE TABLE Persons ( P_Id int NOT NULL, L_name varchar(30) NOT NULL, F_name varchar(30), City varchar(30), CHECK(P_Id>0) ) ;

the above will accepts the input values in P_Id which should be greater than 0 (Zero).

If we want to ALTER the table
ALTER TABLE Persons ADD CHECK (P_Id>0) ;
If we want to DROP the table
ALTER TABLE Persons DROP CONSTRAINT check_persons;

6. DEFAULT :- is used to insert a default value into a column. The default value will be added to all the records in the table.

Eg: CREATE TABLE Persons
( P_Id int NOT NULL,
L_name varchar(30) NOT NULL,
F_name varchar(30),
city varchar(30) DEFAULT 'Bangalore' );

the above will create table Persons with city column for all persons as Bangalore.

If we want to ALTER the table
ALTER TABLE Persons ADD COLUMN City SET DEFAULT 'Bangalore';
If we want to DROP the table
ALTER TABLE Persons DROP City DEFAULT;

SQL ALTER COMMAND: is used to add/delete/modify the columns in an existing table.

the below command is used to ADD a new column DateOFBirth with Date as datatype.

Eg: ALTER TABLE Persons ADD DateOFBirth date;
the below command is used to MODIFY the datatype of the column

Eg: ALTER TABLE Persons ALTER COLUMN DateOFBirth Year;
the below is used to DROP the column

Eg: ALTER TABLE Persons DROP COLUMN DateOFBIrth;

AUTO INCREMENT : used to increment value in column automatically. By default it will increment from 1.

Eg: CREATE TABLE Persons
( P_Id int NOT NULL AUTO_INCREMENT,
L_name varchar(30) NOT NULL,
F_name varchar(30),
city varchar(30),
PRIMARY KEY(P_Id));

If we want to increment value other than 1 , say increment from 100

ALTER TABLE Persons AUTO_INCREMENT =100;

DATA TYPES IN SQL:- mostly there are 3 main types : text, number and Date/time types.

CHAR(size) -- Holds a fixed length string (can contain letters, numbers, and special characters). The fixed size is specified in parenthesis. Can store up to 255 characters

VARCHAR(size) --Holds a variable length string (can contain letters, numbers, and special characters). The maximum size is specified in parenthesis. Can store up to 255 characters. Note: If you put a greater value than 255 it will be converted to a TEXT type

INT(size) -- -2147483648 to 2147483647 normal. 0 to 4294967295 UNSIGNED*. The maximum number of digits may be specified in parenthesis

DATE() -- A date. Format: YYYY-MM-DD

SQL FUNCTIONS: -- are the functions which returns a single value, calculated from values in a column.

The below are Aggregate functions:
1. AVG() -- returns the average value.
2. COUNT() -- returns number of rows.
3.MAX() -- returns the largest value
4.MIN() -- returns the smallest value
5.SUM() --- returns the sum of all columns
6.FIRST() -- returns the first value
7.LAST() -- returns the last value

The below are Scalar functions:

1. UCASE() -- converts a field to uppercase
2. LCASE() -- converts a field to lowecase
3. LEN() -- returns the length of a text field
4. ROUND() -- round the numeric field to the number of decimals specified.
5. FORMAT() -- formats how a field is to be displayed.

JAVA Questions And Answers

noreply@blogger.com (kareem) — Sat, 29 Oct 2011 09:07:00 -0700

Q) What is difference between Java and C++?

A) (i) Java does not support pointers. Pointers are inherently insecure and troublesome. Since pointers do not exist in Java. (ii) Java does not support operator overloading. (iii) Java does not perform any automatic type conversions that result in a loss of precision (iv) All the code in a Java program is encapsulated within one or more classes. Therefore, Java does not have global variables or global functions. (v) Java does not support multiple inheritance.

Java does not support destructors, but rather, add the finalize() function. (vi) Java does not have the delete operator. (vii) The << and >> are not overloaded for I/O operations

Q) Opps concepts

Polymorphism

Ability to take more than one form, in java we achieve this using Method Overloading (compile time polymorphism), Method overriding (runtime polymorphism)

Inheritance

Is the process by which one object acquires the properties of another object. The advantages of inheritance are reusability of code and accessibility of variables and methods of the super class by subclasses.

Encapsulation

Wrapping of data and function into a single unit called encapsulation. Ex:- all java programs.

(Or)

Nothing but data hiding, like the variables declared under private of a particular class are accessed only in that class and cannot access in any other the class. Or Hiding the information from others is called as Encapsulation. Or Encapsulation is the mechanism that binds together code and data it manipulates and keeps both safe from outside interference and misuse.

Abstraction

Nothing but representing the essential futures without including background details.

Dynamicbinding

Code associated with a given procedural call is not known until the time of the call at runtime. Dynamic binding is nothing but late binding.

Q) class & object?

class à class is a blue print of an object

Object à instance of class.

Q) Object creation?
Object is constructed either on a memory heap or on a stack.

Memory heap
Generally the objects are created using the new keyword. Some heap memory is allocated to this newly created object. This memory remains allocated throughout the life cycle of the object. When the object is no more referred, the memory allocated to the object is eligible to be back on the heap.

Stack
During method calls, objects are created for method arguments and method variables. These objects are created on stack.

Q) System.out.println()

à println() is a methd of java.io.printWriter.

à “out” is an instance variable of java.lang.System class.

Q) Transient & volatile

Transient --> The transient modifier applies to variables only, the object are variable will not persist. Transient variables are not serialized.

Volatile --> value will be changed unexpectedly by the other part of the program, "it tells the compiler a variable may change asynchronously due to threads"

Q) Access Specifiers & Access modifiers?

Access Specifiers à A.S gives access privileges to outside of application (or) others, they are Public, Protected, Private, Defaults.

Access Modifiers à A.M which gives additional meaning to data, methods and classes, final cannot be modified at any point of time.

	Private	Public	Protected	No modifier
Same class	No	Yes	Yes	Yes
Same package Subclass	No	Yes	Yes	Yes
Same package non-subclass	No	Yes	Yes	Yes
Different package subclass	No	Yes	Yes	No
Different package non-subclass	No	Yes	No	No

Q) Default Values

long	-2^63 to 2^63 –1 à 0L	double	0.0d
Int	-2^31 to 2^31 –1 à 0	float	0.0f
Short	-2^15 to 2^15 –1 à 0	Boolean	false
Byte	-2^7 to 2^7 –1 à 0	char	0 to 2^7 –1 à null character (or) ‘\u 0000’

Q) Byte code & JIT compiler & JVM & JRE & JDK

à Byte code is a highly optimized set of instructions. JVM is an interpreter for byte code. Translating a java program into byte code helps makes it much easier to run a program in a wide variety of environment.

à JVM is an interpreter for byte code

à JIT (Just In Time) is a part of JVM, it compiles byte code into executable code in real time, will increase the performance of the interpretations.

à JRE is an implementation of the Java Virtual Machine, which actually executes Java programs.

à JDK is bundle of software that you can use to develop Java based software, Tools provided by JDK is

(i) javac – compiler (ii) java – interpretor (iii) jdb – debugger (iv) javap - Disassembles

(v) appletviewer – Applets (vi) javadoc - documentation generator (vii) javah - 'C' header file generator

Q) Wrapper classes

Primitive data types can be converted into objects by using wrapper classes. These are java.lang.package.

Q) Does Java pass method arguments by value or by reference?

Java passes all arguments by value, not by reference

Q) Arguments & Parameters

While defining method, variable passed in the method are called parameters. While using those methods, values passed to those variables are called arguments.

Q) Public static void main (String [] args)

à We can overLoad the main() method.

à What if the main method is declared as “Private”?

The program compiles properly but at runtime it will give "Main method not public." Message

à What if the static modifier is removed from the signature of the main method?

Program compiles. But at runtime throws an error "NoSuchMethodError".

à We can write “static public void” instead of “public static void” but not “public void static”.

à Protected static void main(), static void main(), private static void main() are also valid.

à If I do not provide the String array as the argument to the method?

Program compiles but throws a runtime error "NoSuchMethodError".

à If no arguments on the command line, String array of Main method will be empty or null?

It is empty. But not null.

à Variables can have the same name as a method or a class

Q) Can an application have multiple classes having main() method?

A) Yes it is possible. While starting the application we mention the class name to be run. The JVM will look for the Main method only in the class whose name you have mentioned. Hence there is not conflict amongst the multiple classes having main method.

Q) Can I have multiple main methods in the same class?

A) No the program fails to compile. The compiler says that the main method is already defined in the class.

Q) Constructor

The automatic initialization is performed through the constructor, constructor has same name has class name. Constructor has no return type not even void. We can pass the parameters to the constructor. this() is used to invoke a constructor of the same class. Super() is used to invoke a super class constructor. Constructor is called immediately after the object is created before the new operator completes.

à Constructor can use the access modifiers public, protected, private or have no access modifier

à Constructor can not use the modifiers abstract, static, final, native, synchronized or strictfp

à Constructor can be overloaded, we cannot override.

à You cannot use this() and Super() in the same constructor.

Class A(

A(){

System.out.println(“hello”);

}}

Class B extends A {

B(){

System.out.println(“friend”);

}}

Class print {

Public static void main (String args []){

B b = new B();

}

o/p:- hello friend

Q) Garbage collection

G.C is also called automatic memory management as JVM automatically removes the unused variables/objects (value is null) from the memory. User program cann't directly free the object from memory, instead it is the job of the garbage collector to automatically free the objects that are no longer referenced by a program. Every class inherits finalize() method from java.lang.Object, the finalize() method is called by garbage collector when it determines no more references to the object exists. In Java, it is good idea to explicitly assign null into a variable when no more in use, calling System.gc() and Runtime.gc(), JVM tries to recycle the unused objects, but there is no guarantee when all the objects will garbage collected. Garbage collection is a low-priority thread.

G.C is a low priority thread in java, G.C cannot be forced explicitly. JVM may do garbage collection if it is running short of memory. The call System.gc() does NOT force the garbage collection but only suggests that the JVM may make an effort to do garbage collection.

Q) How an object becomes eligible for Garbage Collection?

A) An object is eligible for garbage collection when no object refers to it, An object also becomes eligible when its reference is set to null. The objects referred by method variables or local variables are eligible for garbage collection when they go out of scope.

Integer i = new Integer(7);
i = null;

Q) Final, Finally, Finalize

Final: - When we declare a sub class a final the compiler will give error as “cannot subclass final class” Final to prevent inheritance and method overriding. Once to declare a variable as final it cannot occupy memory per instance basis.

à Final class cannot have static methods

à Final class cannot have abstract methods (Because of final class never allows any class to inherit it)

à Final class can have a final method.

Finally: - Finally create a block of code that will be executed after try catch block has completed. Finally block will execute whether or not an exception is thrown. If an exception is thrown, the finally block will execute even if no catch statement match the exception. Any time a method is about to return to the caller from inside try/catch block, via an uncaught exception or an explicit return statement, the finally clause is also execute.

Using System.exit() in try block will not allow finally code to execute

Finalize: - some times an object need to perform some actions when it is going to destroy, if an object holding some non-java resource such as file handle (or) window character font, these resources are freed before the object is going to destroy.

Q) Can we declare abstract method in final class?

A) It indicates an error to declare abstract method in final class. Because of final class never allows any class to inherit it.

Q) Can we declare final method in abstract class?

A) If a method is defined as final then we can’t provide the reimplementation for that final method in it’s derived classes i.e overriding is not possible for that method. We can declare final method in abstract class suppose of it is abstract too, then there is no used to declare like that.

Q) Superclass & Subclass

A super class is a class that is inherited whereas subclass is a class that does the inheriting

Q) How will u implement 1) polymorphism 2) multiple inheritance 3) multilevel inheritance in java?

A) Polymorphism – overloading and overriding

Multiple inheritances – interfaces.

Multilevel inheritance – extending class.

Q) Overloading & Overriding?

Overloading (Compile time polymorphism)

Define two or more methods within the same class (or) subclass that share the same name and their number of parameter, order of parameter & return type are different then the methods are said to be overloaded.

· Overloaded methods do not have any restrictions on what return type of Method (Return type are different) (or) exceptions can be thrown. That is something to worry about with overriding.

· Overloading is used while implementing several methods that implement similar behavior but for different data types.

Overriding (Runtime polymorphism)

When a method in a subclass has the same name, return type & parameters as the method in the super class then the method in the subclass is override the method in the super class.

à The access modifier for the overriding method may not be more restrictive than the access modifier of the superclass method.

· If the superclass method is public, the overriding method must be public.

· If the superclass method is protected, the overriding method may be protected or public.

· If the superclass method is package, the overriding method may be packagage, protected, or public.

· If the superclass methods is private, it is not inherited and overriding is not an issue.

· Methods declared as final cannot be overridden.

à The throws clause of the overriding method may only include exceptions that can be thrown by the superclass method, including its subclasses.

à Only member method can be overriden, not member variable

class Parent{

int i = 0;

void amethod(){

System.out.println("in Parent");

}

class Child extends Parent{

int i = 10;

void amethod(){

System.out.println("in Child");

}

class Test{

public static void main(String[] args){

Parent p = new Child();

Child c = new Child();

System.out.print("i="+p.i+" ");

p.amethod ();

System.out.print("i="+c.i+" ");

c.amethod();

}

o/p: - i=0 in Child i=10 in Child

Q) Final variable

Once to declare a variable as final it cannot occupy memory per instance basis.

Q) Static block

Static block which exactly executed exactly once when the class is first loaded into JVM. Before going to the main method the static block will execute.

Q) Static variable & Static method

Static variables & methods are instantiated only once per class. In other words they are class variables, not instance variables. If you change the value of a static variable in a particular object, the value of that variable changes for all instances of that class.

Static methods can be referenced with the name of the class. It may not access the instance variables of that class, only its static variables. Further it may not invoke instance (non-static) methods of that class unless it provides them with some object.

à When a member is declared a static it can be accessed before any object of its class are created.

à Instance variables declared as static are essentially global variables.

à If you do not specify an initial value to an instance & Static variable a default value will be assigned automatically.

à Methods declared as static have some restrictions they can access only static data, they can only call other static data, they cannot refer this or super.

à Static methods cant be overriden to non-static methods.

à Static methods is called by the static methods only, an ordinary method can call the static methods, but static methods cannot call ordinary methods.

à Static methods are implicitly "final", because overriding is only done based on the type of the objects

à They cannot refer “this” are “super” in any way.

Q) Class variable & Instance variable & Instance methods & class methods

Instance variable à variables defined inside a class are called instance variables with multiple instance of class, each instance has a variable stored in separate memory location.

Class variables à you want a variable to be common to all classes then we crate class variables. To create a class variable put the “static” keyword before the variable name.

Class methods à we create class methods to allow us to call a method without creating instance of the class. To declare a class method use the “static” key word .

Instance methods à we define a method in a class, in order to use that methods we need to first create objects of the class.

Q) Static methods cannot access instance variables why?

Static methods can be invoked before the object is created; Instance variables are created only when the new object is created. Since there is no possibility to the static method to access the instance variables. Instance variables are called called as non-static variables.

Q) String & StringBuffer

String is a fixed length of sequence of characters, String is immutable.

StringBuffer represent growable and writeable character sequence, StringBuffer is mutable which means that its value can be changed. It allocates room for 16-addition character space when no specific length is specified. Java.lang.StringBuffer is also a final class hence it cannot be sub classed. StringBuffer cannot be overridden the equals() method.

Q) Conversions

String to Int Conversion: -

int I = integer.valueOf(“24”).intValue();

int x = integer.parseInt(“433”);

float f = float.valueOf(23.9).floatValue();

Int to String Conversion :-

String arg = String.valueOf(10);

Q) Super()

Super() always calling the constructor of immediate super class, super() must always be the first statements executed inside a subclass constructor.

Q) What are different types of inner classes?

A) Nested top-level classes- If you declare a class within a class and specify the static modifier, the compiler treats the class just like any other top-level class. Any class outside the declaring class accesses the nested class with the declaring class name acting similarly to a package. e.g., outer.inner. Top-level inner classes implicitly have access only to static variables. There can also be inner interfaces. All of these are of the nested top-level variety.

Member classes - Member inner classes are just like other member methods and member variables and access to the member class is restricted, just like methods and variables. This means a public member class acts similarly to a nested top-level class. The primary difference between member classes and nested top-level classes is that member classes have access to the specific instance of the enclosing class.

Local classes - Local classes are like local variables, specific to a block of code. Their visibility is only within the block of their declaration. In order for the class to be useful beyond the declaration block, it would need to implement a more publicly available interface. Because local classes are not members the modifiers public, protected, private and static are not usable.

Anonymous classes - Anonymous inner classes extend local inner classes one level further. As anonymous classes have no name, you cannot provide a constructor.

à Inner class inside method cannot have static members or blocks

Q) Which circumstances you use Abstract Class & Interface?

--> If you need to change your design make it an interface.

--> Abstract class provide some default behaviour, A.C are excellent candidates inside of application framework. A.C allow single inheritance model, which should be very faster.

Q) Abstract Class

Any class that contain one are more abstract methods must also be declared as an abstract, there can be no object of an abstract class, we cannot directly instantiate the abstract classes. A.C can contain concrete methods.

àAny sub class of an Abstract class must either implement all the abstract methods in the super class or be declared itself as Abstract.

à Compile time error occur if an attempt to create an instance of an Abstract class.

à You cannot declare “abstract constructor” and “abstract static method”.

à An “abstract method” also declared private, native, final, synchronized, strictfp, protected.

à Abstract class can have static, final method (but there is no use).

à Abstract class have visibility public, private, protected.

à By default the methods & variables will take the access modifiers is <default>, which is accessibility as package.

à An abstract method declared in a non-abstract class.

à An abstract class can have instance methods that implement a default behavior.

à A class can be declared abstract even if it does not actually have any abstract methods. Declaring such a class abstract indicates that the implementation is somehow incomplete and is meant to serve as a super class for one or more subclasses that will complete the implementation.

à A class with an abstract method. Again note that the class itself is declared abstract, otherwise a compile time error would have occurred.

Abstract class A{

Public abstract callme();

Void callmetoo(){

}

class B extends A(

      void callme(){

}

class AbstractDemo{

public static void main(string args[]){

B b = new B();

b.callme();

b.callmetoo();

}

Q) When we use Abstract class?

A) Let us take the behaviour of animals, animals are capable of doing different things like flying, digging,

Walking. But these are some common operations performed by all animals, but in a different way as well. When an operation is performed in a different way it is a good candidate for an abstract method.

Public Abstarctclass Animal{

Public void eat(food food) {

}

public void sleep(int hours) {

}

public abstract void makeNoise()

}

public Dog extends Animal

{

public void makeNoise() {

System.out.println(“Bark! Bark”);

}

public Cow extends Animal

{

public void makeNoise() {

System.out.println(“moo! moo”);

}

Q) Interface

Interface is similar to class but they lack instance variable, their methods are declared with out any body. Interfaces are designed to support dynamic method resolution at run time. All methods in interface are implicitly

abstract, even if the abstract modifier is omitted. Interface methods have no implementation;

Interfaces are useful for?

a) Declaring methods that one or more classes are expected to implement

b) Capturing similarities between unrelated classes without forcing a class relationship.

c) Determining an object's programming interface without revealing the actual body of the class.

Why Interfaces?

“ one interface multiple methods “ signifies the polymorphism concept.

Interface has visibility public.

Interface can be extended & implemented.

An interface body may contain constant declarations, abstract method declarations, inner classes and inner interfaces.

All methods of an interface are implicitly Abstract, Public, even if the public modifier is omitted.

An interface methods cannot be declared protected, private, strictfp, native or synchronized.

All Variables are implicitly final, public, static fields.

A compile time error occurs if an interface has a simple name the same as any of it's enclosing classes or interfaces.

An Interface can only declare constants and instance methods, but cannot implement default behavior.

top-level interfaces may only be declared public, inner interfaces may be declared private and protected but only if they are defined in a class.

A class can only extend one other class.

A class may implements more than one interface.

Interface can extend more than one interface.

Interface A

{

final static float pi = 3.14f;

}

class B implements A

{

public float compute(float x, float y) {

return(x*y);

}

class test{

public static void main(String args[])

{

A a = new B();

a.compute();

}

Q) Diff Interface & Abstract Class?

à A.C may have some executable methods and methods left unimplemented. Interface contains no implementation code.

à An A.C can have nonabstract methods. All methods of an Interface are abstract.

à An A.C can have instance variables. An Interface cannot.

à An A.C must have subclasses whereas interface can't have subclasses

à An A.C can define constructor. An Interface cannot.

à An A.C can have any visibility: public, private, protected. An Interface visibility must be public (or) none.

à An A.C can have instance methods that implement a default behavior. An Interface can only declare constants and instance methods, but cannot implement default behavior.

Q) What is the difference between Interface and class?

à A class has instance variable and an Interface has no instance variables.

à Objects can be created for classes where as objects cannot be created for interfaces.

à All methods defined inside class are concrete. Methods declared inside interface are without any body.

Q) What is the difference between Abstract class and Class?

à Classes are fully defined. Abstract classes are not fully defined (incomplete class)

à Objects can be created for classes, there can be no objects of an abstract class.

Q) What are some alternatives to inheritance?

A) Delegation is an alternative to inheritance. Delegation means that you include an instance of another class as an instance variable, and forward messages to the instance. It is often safer than inheritance because it forces you to think about each message you forward, because the instance is of a known class, rather than a new class, and because it doesn’t force you to accept all the methods of the super class: you can provide only the methods that really make sense. On the other hand, it makes you write more code, and it is harder to re-use (because it is not a subclass).

Q) Serializable & Externalizable

Serializable --> is an interface that extends serializable interface and sends data into streams in compressed format. It has 2 methods writeExternal(objectOutput out), readExternal(objectInput in).

Externalizable à is an Interface that extends Serializable Interface. And sends data into Streams in Compressed Format. It has two methods, writeExternal(ObjectOuput out) and readExternal(ObjectInput in)

Q) Internalisation & Localization

Internalisation -- Making a programme to flexible to run in any locale called internalisation.

Localization -- Making a programme to flexible to run in a specific locale called Localization.

Q) Serialization

Serialization is the process of writing the state of the object to a byte stream, this is useful when ever you want to save the state of your programme to a persistence storage area.

Q) Synchronization

Synchronization is a process of controlling the access of shared resources by the multiple threads in such a manner that only one thread can access one resource at a time. (Or) When 2 are more threads need to access the shared resources they need to some way ensure that the resources will be used by only one thread at a time. This process which is achieved is called synchronization.

(i) Ex: - Synchronizing a function:
public synchronized void Method1 () {
}

(i) Ex: - Synchronizing a block of code inside a function:
public myFunction (){
synchronized (this) {
}
}

(iii) Ex: - public Synchronized void main(String args[])

But this is not the right approach because it means servlet can handle one request at a time.

(iv) Ex: - public Synchronized void service()

Servlet handle one request at a time in a serialized manner

Q) Different level of locking using Synchronization?

A) Class level, Object level, Method level, Block level

Q) Monitor

A monitor is a mutex, once a thread enter a monitor, all other threads must wait until that thread exist the monitor.

Q) Diff = = and .equals()?

A) == à Compare object references whether they refer to the sane instance are not.

equals () à method compare the characters in the string object.

StringBuffer sb1 = new StringBuffer("Amit");

StringBuffer sb2= new StringBuffer("Amit");

String s1 = "Amit";

String s2 = "Amit";

String s3 = new String("abcd");

String s4 = new String("abcd");

String ss1 = "Amit";

(sb1==sb2); à F	(s1.equals(s2)); à T
(sb1.equals(sb2)); à F	((s1==s2)); à T
(sb1.equals(ss1)); à F	(s3.equals(s4)); à T
	((s3==s4)); à F

String s1 = "abc";

String s2 = new String("abc");

s1 == s2 à F

s1.equals(s2)) à T

Q) Marker Interfaces (or) Tagged Interfaces :-

An Interface with no methods. Is called marker Interfaces, eg. Serializable, SingleThread Model, Cloneable.

Q) URL Encoding & URL Decoding

URL Encoding is the method of replacing all the spaces and other extra characters into their corresponding Hex Characters and URL Decoding is the reverse process converting all Hex Characters back their normal form.

Q) URL & URLConnection

URL is to identify a resource in a network, is only used to read something from the network.

URL url = new URL(protocol name, host name, port, url specifier)

URLConnection can establish communication between two programs in the network.

URL hp = new URL(“www.yahoo.com”);

URLConnection con = hp.openConnection();

Q) Runtime class

Runtime class encapsulate the run-time environment. You cannot instantiate a Runtime object. You can get a reference to the current Runtime object by calling the static method Runtime.getRuntime()

Runtime r = Runtime.getRuntime()

Long mem1;

Mem1 = r.freeMemory();

Mem1 = r.totalMemory();

Q) Execute other programs

You can use java to execute other heavy weight process on your multi tasking operating system, several form of exec() method allow you to name the programme you want to run.

Runtime r = Runtime.getRuntime();

Process p = null;

Try{

p = r.exce(“notepad”);

p.waiFor()

}

Q) System class

System class hold a collection of static methods and variables. The standard input, output, error output of the java runtime are stored in the in, out, err variables.

Q) Native Methods

Native methods are used to call subroutine that is written in a language other than java, this subroutine exist as executable code for the CPU.

Q) Cloneable Interface

Any class that implements the cloneable interface can be cloned, this interface defines no methods. It is used to indicate that a class allow a bit wise copy of an object to be made.

Q) Clone

Generate a duplicate copy of the object on which it is called. Cloning is a dangerous action.

Q) Comparable Interface

Classes that implements comparable contain objects that can be compared in some meaningful manner. This interface having one method compare the invoking object with the object. For sorting comparable interface will be used.

Ex:- int compareTo(Object obj)

Q) Class

Class encapsulate the run-time state of an object or interface. Methods in this class are

static Class forName(String name) throws ClassNotFoundException	getClass()
getClassLoader()	getConstructor()
getField()	getDeclaredFields()
getMethods()	getDeclearedMethods()
getInterface()	getSuperClass()

Q) java.jlang.Reflect (package)

Reflection is the ability of software to analyse it self, to obtain information about the field, constructor, methods & modifier of class. You need this information to build software tools that enables you to work with java beans components.

Q) InstanceOf

      Instanceof means by which your program can obtain run time type
information about an object.

Ex:- A a = new A();

       a.instanceOf A;

Q) Java pass arguments by value are by reference?

A) By value

Q) Java lack pointers how do I implements classic pointer structures like 
linked list?

A) Using object reference.

Q) Bin & Lib in jdk?

Bin contains all tools such as javac, appletviewer and awt tool.

Lib contains API and all packages.

Selenium PageObject

noreply@blogger.com (kareem) — Wed, 5 Oct 2011 21:41:00 -0700

PageObject

• PageObjects is a design pattern where objects representing your pages are exposed to the
test logic as services providing access to the elements and logic of your page
• The pattern is defined along the following:
o The public methods exposes the services the page offers
o The internals of the page should not be exposed
o Don’t make assertions in the PageObject class, it is the test logic’s work
o Methods return other PageObjects
o You don’t need to represent an entire page, just the services you need to test
o One action can have several methods depending on the result of these actions
• PageObjects' methods exposes actions on the page (a login action for instance) and must return another PageObject:

class LoginPage
@error_message
//Once logged-in, the server redirects to the home page so the login methods should return a PageObject representing the homepage
def loginAs(username, password)
# ...
HomePage.new
end

//We test a failed login gives the correct message. Since it is a failed login, we stay on the login page so we return the same object
def loginAsExpectingError(username, password)
# ...
# error_message = something
self
end
def error_message
@error_message
//We can return here the error message displayed on the page in case of failed login
end

public class LoginPage {
private String errorMessage;
//Once logged-in, the server redirects to the home page so the login methods should return a PageObject representing the homepage

public HomePage loginAs(username, password) {
...
return new HomePage();
}
public LoginPage loginAsExpectingError(username, password) {
//We test a failed login gives the correct message. Since it is a failed login, we stay on the login page so we return the same object

...
errorMessage = something;
return self;
}

public void getErrorMessage() {
return errorMessage;
//We can return here the error message displayed on the page in case of failed login
}
}

• The PageObject pattern is a good practice because:
- It facilitates code reuse: think about inheritance and abstract classes
- It facilitates maintenance: code logic and page are separated

PageObject Pattern
We’re going to transform our tests to follow the PageObject pattern
Java
• You will find in the project in the labs/lab6/java folder a Page class as well as a Lab6 containing the test to run
• The Page class is the class from which all your projects will inherit from
• The Lab6 class contains the test and therefore, the methods to implement in your page objects

Selenium RC

noreply@blogger.com (kareem) — Wed, 5 Oct 2011 21:36:00 -0700

Overview of Selenium RC
While Selenium IDE may seem a productive and efficient tool for writing test-cases, it lacks many essential features of a testing tool:
Conditional statements
Loops
Logging
Exception handling
Reporting
Test fixtures and data-driven tests
Test dependencies
Taking screenshots
Selenium RC is the answer to a more powerful test-suite for your applications.
It follows a client/server model allowing client libraries to execute tests on a browser controlled by the server.

Selenium Server
• Selenium server is the program that drives the browser
• It embeds Selenium Core framework and injects it into the browser
• It communicates with the running test client and drives the browser
• Client tests sends commands that the server interpretes in order to drive the browser
• The server sends back results to the client
• Client and server communicates via HTTP GETs and POSTs so you can easily plug into
• Server is configurable at startup via command-line options. use java -jar selenium-server.jar -h to see the list of options
Client libraries
• Client libraries provides the API to program tests and execute them on the server
• Each implementation provides access to all Selenium commands
• Supported API implementation exists in:
- Java (also accessible via Groovy)
- Net
- PHP
- Python
- Perl
- Ruby

Installation of Selenium RC

Prerequisites
• A JVM installed on the system
• A Ruby distribution with the rspec and selenium-client gems installed if
• you’re working
• The Selenium RC archive

Running The RC Server
• Unzip the Selenium RC archive somewhere on your system
• Go into the selenium-rc, then the selenium-server folder
• Open a terminal in this folder and enter the command java -jar selenium-server.jar
• If there’s no error messages, your Selenium RC server should be running now.

Running A Test (Java)
• Create a new Java project in Eclipse or your Java IDE
• Add the selenium-java-client-driver.jar jar to the project’s classpath
• Add a new JUnit test-case to the project. When asked, select Junit 4
• You should now have an empty .java file
• Open the lab2 test-case on Selenium IDE
• On Selenium IDE, open the Options menu then Format… and click Java (Junit)
• Copy/paste the contents in the JUnit file on Eclipse
• Change the package name at your will
• You may have to fix the imports
o Click on the following icon and choose the most appropriate option to correct the file
o You may also press Ctrl + Shift + O to let Eclipse do it automatically
• At this point you shouldn’t have any more errors and you are ready to run the test
• Selenium RC will open a couple of Firefox windows and run the test

Junit
• Junit is the reference unit-testing framework for Java
• The framework allows you to test your applications using specific classes containing the logic performing actions on the tested classes and checking the results
• Eclipse provides support for Junit, so we’ll be using that
• JUnit 3 uses named methods to detect set-up and test methods

Selenium Locators

noreply@blogger.com (kareem) — Wed, 5 Oct 2011 21:26:00 -0700

Locators
Selenium uses what is called locators to find and match the elements of your page that it needs to interact with.Selenium Locators can be classified into two categories:
Structure-based locators: locators that rely on the structure of the page to find elements.

XPath

DOM

CSS

Attributes-based locators: locators that relies on the attributes of the elements to locate them

Identifier

Name

Link

CSS

In General there are 8 locators strategies included in Selenium:
• Identifier
• Id
• Name
• Link
• DOM
• XPath
• CSS
• UI-element

Will look each of the locator in detail:

1. Identifier:
works with the id and name attributes of your html tags. Let’s consider the following example:

<html>
<body>
<form id="login">
<input name="username" type="text"/>
<input name="password" type="password"/>
<input name="submit" type="submit" value="Continue!"/>
</form>
</body>
</html>

Valid locators for this snippet are :
• identifier=login
• identifier=username
• submit

Id

The Id strategy looks for an element in the page having an id attribute corresponding to the specified pattern. <label id="my_id" /> will be matched by a locator like id=my_id or just my_id

Name

Like the Id strategy, but on the name attribute. You can also specify a filter to refine your locator. Currently, there are two filter types :
• Value : matches elements with a name attribute and where the value follows a pattern. The following example illustrates the interest of filters :
<html>
<body>
<div id="pancakes">
<button type="button" name="pancake" value="Blueberry">Blueberry</button>
<button type="button" name="pancake" value="Banana">Banana</button>
<button type="button" name="pancake" value="Strawberry">Strawberry</button>
</div>
</body>
</html>

Scenario:
we just added a strawberry pancake in our application and we want to test that the button that adds it into the cart works. With a locator like name=pancake, Selenium will find 3 elements and return the first one : the test will never fail even if the strawberry button is not here! Use a value filter like name=pancake value=Strawberry and the locator successfully identifies the Strawberry button.
• Index : same as name but works with an index. Using the previous example, the locator name=pancake index=2 will select the Strawberry button.

Link
This strategy is intended to select links only and selects the anchor element containing the specified text: link=The text of the link

DOM
The DOM strategy works by locating elements that matches the javascript expression refering to an element in the DOM of the page.
• dom=document.div['pancakes'].button[0]
• document.div[0].button[2]
• dom=function foo() { return document.getElementById("pancakes"); }; foo();

XPath
While DOM is the recognized standard for navigation through an HTML element tree, XPath is the standard navigation tool for XML; and an HTML document is also an XML document (xHTML). XPath is used everywhere where there is XML. Valid XPath locators can be:
• xpath=//button[@value="Blueberry"]: matches the Blueberry button
• //div[@id="pancakes"]/button[0]: same thing

CSS
The CSS locator strategy uses CSS selectors to find the elements in the page. Selenium supports CSS 1 through 3 selectors

UI-Elements
• UI-element is a rather new locator
• It was at first a Selenium IDE extension
• It is now fully integrated into Selenium

If you are not sure that you didnt got from above, below is reference:

Element Locators

Element Locators tell Selenium which HTML element a command refers to. The format of a locator is:

locatorType=argument

We support the following strategies for locating elements:

identifier=id: Select the element with the specified @id attribute. If no match is found, select the first element whose @name attribute is id. (This is normally the default; see below.)
id=id: Select the element with the specified @id attribute.
name=name: Select the first element with the specified @name attribute.
- username
- name=username
The name may optionally be followed by one or more element-filters, separated from the name by whitespace. If the filterType is not specified, value is assumed.
- name=flavour value=chocolate
dom=javascriptExpression: Find an element by evaluating the specified string. This allows you to traverse the HTML Document Object Model using JavaScript. Note that you must not return a value in this string; simply make it the last expression in the block.
- dom=document.forms['myForm'].myDropdown
- dom=document.images[56]
- dom=function foo() { return document.links[1]; }; foo();
xpath=xpathExpression: Locate an element using an XPath expression.
- xpath=//img[@alt='The image alt text']
- xpath=//table[@id='table1']//tr[4]/td[2]
- xpath=//a[contains(@href,'#id1')]
- xpath=//a[contains(@href,'#id1')]/@class
- xpath=(//table[@class='stylee'])//th[text()='theHeaderText']/../td
- xpath=//input[@name='name2' and @value='yes']
- xpath=//*[text()="right"]
link=textPattern: Select the link (anchor) element which contains text matching the specified pattern.
- link=The link text
css=cssSelectorSyntax: Select the element using css selectors. Please refer to CSS2 selectors, CSS3 selectors for more information. You can also check the TestCssLocators test in the selenium test suite for an example of usage, which is included in the downloaded selenium core package.
- css=a[href="#id3"]
- css=span#firstChild + span
Currently the css selector locator supports all css1, css2 and css3 selectors except namespace in css3, some pseudo classes(:nth-of-type, :nth-last-of-type, :first-of-type, :last-of-type, :only-of-type, :visited, :hover, :active, :focus, :indeterminate) and pseudo elements(::first-line, ::first-letter, ::selection, ::before, ::after).

Without an explicit locator prefix, Selenium uses the following default strategies:

dom, for locators starting with "document."
xpath, for locators starting with "//"
identifier, otherwise

Element Filters

Element filters can be used with a locator to refine a list of candidate elements. They are currently used only in the 'name' element-locator.
Filters look much like locators, ie.

filterType=argument
Supported element-filters are:
value=valuePattern

Matches elements based on their values. This is particularly useful for refining a list of similarly-named toggle-buttons.
index=index

Selects a single element based on its position in the list (offset from zero).

String-match Patterns

Various Pattern syntaxes are available for matching string values:

glob:pattern: Match a string against a "glob" (aka "wildmat") pattern. "Glob" is a kind of limited regular-expression syntax typically used in command-line shells. In a glob pattern, "*" represents any sequence of characters, and "?" represents any single character. Glob patterns match against the entire string.
regexp:regexp: Match a string using a regular-expression. The full power of JavaScript regular-expressions is available.
exact:string: Match a string exactly, verbatim, without any of that fancy wildcard stuff.

If no pattern prefix is specified, Selenium assumes that it's a "glob" pattern.

Selenium Commands

noreply@blogger.com (kareem) — Wed, 5 Oct 2011 21:14:00 -0700

Commands
The Selenium API defines dozens of commands that can be categorized into the following:
• Actions
• Accessors
• Assertions

Actions
Actions are commands that change the state of the application like clicking links or buttons, select an option in a <select> or type a character sequence in a given textbox.

Eg : clickAndWait(locator) command which will trigger a click and stop the test until the browser has finished loading a new page.

Accessors

Accessors inspect the state of the application and store values in variables.
Eg : storeCookies(variableName) stores all the cookies in use in the current page in the variable variableName.

Assertions
Assertions are also able to inspect the current page but:

- They’re made to return a boolean value
- This boolean represents the conformity of the element to a desired pattern
- Usually, the pattern represents the state of an element.

• Assertions come into 3 flavors:
- assert : if assertion fails, test is aborted and marked as failed : assertTitle(pattern) will fail if the title of the page doesn’t correspond to the pattern argument.
- verify : if a verification fails, the test doesn’t stop but a trace will be printed in the log.
- waitFor : these commands pause the test until a condition is satisfied or a timeout is reached.

Selenium Test Cases And Test Suites

noreply@blogger.com (kareem) — Wed, 5 Oct 2011 21:03:00 -0700

Selenese
• Selenium IDE produces tests that are written in a DSL (Domain Specific Language) called Selenese Commands.
• Selenese tests are simple xHTML tables of 3 columns and as many rows that there are steps in your test.
The rule for these commands is:
o A method on the first column: the action to perform
o A locator on the second column: the subject of the method (ie: what element is acted upon)
o A value on the third one: the value to be passed to the method (what to type in a text field for instance)

Pizza Test

Pizza Test
open	/
type	q	pizza
click	btnG
assertTextPresent		regexp:pizza

1. The subject of the command open: the root of the application here
2. q is the locator referring to the text field in which type will write pizza
3. click doesn’t need a second argument, we just click on an element (which locator is btnG)
4. assertTextPresent doesn’t need a locator since it searches on the entire page: we just need what to look for

And the corresponding source below - usually you don’t have to touch it, Selenium IDE will do it for you:
Selenese test-case source.

Test Suites

You can assemble test-cases into a test-suite
• They are also expressed as HTML files
• The test-suite only references test-case files as anchor elements
• The anchors are nested inside a table of 1 column and as many rows as there are test-cases in the test-suite

Selenium IDE

noreply@blogger.com (kareem) — Wed, 5 Oct 2011 20:40:00 -0700

Overview of Selenium IDE

Selenium IDE features:
• record/play mechanism: create/edit tests by recording the user actions on the page
• Debugging feature with step-by-step and breakpoints
• Page abstraction capabilities
• Automatic assertions for the page title
• An extensibility feature allowing the use of plugins or user extensions that extend the capabilities of Selenium IDE

Presentation: How Selenium IDE look like

The interface features the following elements:
• An action bar to control the test (1)

Action bar has the following:
1.The base url of the application
2.Test speed
3.Run test-suite
4.Run the selected test case only
5.Pause the test
6.Next step (while paused only)
7.Open Selenium TestRunner
8.Apply rollups (see Section 9.5, “Rollups”)
9.Start/Stop recording

• A test-suite tool (2)
Shows the tests in the current test-suite along with the results.
• A test editor (3)

Test Editor has following sections:
1.The test steps
2.The command of the current step
3.The locator argument
4.‘Find’ button highlights the target of the locator on the page
5.The value argument
• A tool panel (4)

Tool Panel has following sections:

1.Log: shows the execution log of the current tests and displays errors
2.Reference: displays the documentation of the command actually selected
3.UI-Element: diplays the ui-element mappings actually in use
4.Rollup: shows rollup rules
5.Stored-vars : displays current stored variables
6.Log level (only with log panel): customize the verbosity of the log
7.Clear log (only with log panel): clears the log

Export Features

A most interesting feature of Selenium IDE: export to Selenium RC. Selenium IDE is able to export test cases in the following formats:
• Java (Junit 3/4 and TestNG)
• Groovy (Junit)
• C#
• Perl
• Python
• PHP
• Ruby (RSpec and Test/Unit)
You can export test-cases or the entire test-suite.

Installation
Selenium IDE is a Firefox extension:
1. Go to the Selenium website (http://www.seleniumhq.org) or the Firefox add-ons website (http://addons.mozilla.org)
2. Download the latest release of selenium IDE(1.0.8 at the time of writing)
3. Follow the instructions and restart Firefox
4. Selenium IDE is accessible from the ‘Tools’ Menu of Firefox

Example Excercise

1. Open Firefox, go to http://www.google.com. Then, open Selenium IDE (‘Tools’ → ‘Selenium IDE’)

2. Make sure the record button is activated, then type in the search field pizza.

3. Click anywhere on the page or press tab to validate the entry. The Selenium IDE window now looks like this:

4. Click the Google Search button. You can see the click command appear in the IDE.
•On the result page, do a right-click and select the assertTitle command:
5. The command appears in the IDE window

Selenium Tutorial

noreply@blogger.com (kareem) — Wed, 5 Oct 2011 20:23:00 -0700

Selenium Overview
• One of the most popular testing frameworks for web applications as of today
• First open-source test framework using an user-centric point of view
• Supports javascript
• Unintrusive and doesn’t need any modifications of your app to test it

Selenium, as of today, is composed of several projects :
1. Selenium Core The JavaScript framework that provides Selenium the ability to drive the browser and execute the tests
2. Selenium IDE The Firefox plugin used to build test-cases and test-suites directly on top of your web-app. You can also export your tests to Selenium RC.
3. Selenium RC A client/server system that allows you to execute tests written in a variety of languages on a local or remote computer and on all major browsers.
4. Selenium Grid Selenium Grid leverages Selenium RC to provide a test environment that spans on multiple machines at once, reducing the testing time.
5. Selenium on Rails A framework that is built especially to test applications running on the Rails framework.
6. CubicTest An Eclipse plugin which purpose is to conceive and execute tests using the pageObjects pattern.
7. Bromine A simple web-based QA tool targeting the single tester that doesn’t want/can’t invest in complex corporate QA solutions.

My First Java Program Using Eclipse IDE

noreply@blogger.com (kareem) — Tue, 19 Jul 2011 03:18:00 -0700

Eclipse is an Integrated Development Environment (IDE) for JAVA.
Download and Install Eclipse IDE. from http://eclipse.org/downloads/ and keep it in separate folder.
Click on eclipse.exe which will ask you the workspace folder, select the default workspace and click on Ok.

Creating First JAVA Class

From the left pane under Navigator section right click and select New -> Java Project.

Specify Project Name and click on Finish button, which will creates new folder with settings, bin and src sub folders.

Under src folder create a package on right clicking on src folder and select package.

Specify the name and click on Finish button.

Right click on this package and select New -> Class

Specify some name and click on Finish button.

Copy paste the following code

package package_name;

public class className

{
public static void main(String[] args) {
System.out.println("Hi, This is My First Java Class I have Ever Created");
}
}

Save the project and right click on it and select Run As Java Application.

Its done, You can see output under Console as " Hi, This is My First Java Class I have Ever Created. "

Cheers :)

Selenium Fitnesse First Script

noreply@blogger.com (kareem) — Thu, 23 Dec 2010 06:32:00 -0800

Follow the below Steps to get create your script.

1. Start Selenium and Fitnesse servers by clicking respective Selenium.vbs and Fitnesse.vbs files

2. It opens two cmd windows which shows.

3. Go to http://localhost:8000/ and click on Edit button on Top left corner of the frontPage

4. Paste the following code at the end of the existing data and click on save button

//*** this code is for creating text and link for the test case ***//

| !c '''Test Suite''' |

| !c !style_pass([[Web Test Suites][FitNesse.SuiteWebTests]])| !style_pass(''Simple Test Case'')|

Or simply paste the following if we don’t need any tabular format.

|[[Web Test Suites][FitNesse.SuiteWebTests]]|FitNesse's suite of Web Tests|

5. On clicking save button it shows the page with tabular format of web test suite, click on that link, again click on Edit button and paste the following code.

//*** this code is for declaration of variables and functions needed for testing***//

!*> Class Path & Global Defines

!path C:\Program Files\Fitnesse\selenium-java-client-driver.jar

!path C:\Program Files\Fitnesse \genericfixture.jar

!define IE {*piiexplore}

!define FF {*pifirefox}

!define sel {selenium=}

!define ds {com.thoughtworks.selenium.DefaultSelenium}

!define host {localhost}

!define port {4444}

!define COLLAPSE_SETUP {true}

!define COLLAPSE_TEARDOWN {true}

----

SuiteWebTests.SetUp

SuiteWebTests.TearDown

SuiteWebTests.GoogleTest

6. Click on SuiteWebTests.SetUp ? link and copy paste the following code

//** this code is for declaration of the page related predefined variables and methods***//

!| DSL Adapter |

| user types | % | into | % | field | type | {2}, {1} |

| user starts the browser | start | |

| users opens the URL | % | open | {1} |

| page has the title | getTitle | |

| user sees the text on the page | % | isTextPresent | {1} |

| page has an element named | % | isElementPresent | {1} |

| page loads in less than | % | seconds | waitForPageToLoad | {1}000 |

| page has URL | getLocation | |

| user clicks on submit button | click | //button[@type='submit'] |

| user clicks on the link named | % | click | link={1} |

| user clicks on the button named | % | clickAt | {1},"" |

| get text from element named | % | getText | xpath=id('{1}') |

| user stops the browser | stop | |

| add a key-value with key | % | and value | % | put | {1}, {2} |

| get value for the key | % | get | {1} |

| show | toString | |

!|Generic Fixture|${sel}${ds}|${host}|${port}|${FF}|http://${host}|

| user starts the browser |

7. Go to SuiteWebTests.TearDown link and paste the following code and click on save

!| Generic Fixture | ${sel} |

| user stops the browser |

8. Go to SuiteWebTests.GoogleTests link and paste the following code and click on save

//** this code is for declaration of the page related methods***//

!define q {fitnesse generic fixture}

!| Generic Fixture | ${sel} |

| users opens the URL | http://www.google.com |

| page has the title | | Google |

| user types | ${q} | into | q | field |

| user clicks on the button named | btnG |

| page loads in less than | 5 | seconds |

| page has the title | | ${q} - Google Search |

| user clicks on the link named | Next |

| page loads in less than | 5 | seconds |

| user clicks on the link named | Next |

| page loads in less than | 5 | seconds |

FitNesse with Selenium using Generic Fixture

noreply@blogger.com (kareem) — Thu, 16 Dec 2010 04:19:00 -0800

Selenium-RC is the solution for tests that need more than simple browser actions and linear execution. Selenium-RC uses the full power of programming languages to create more complex tests like reading and writing files, querying a database, and emailing test results.

You’ll want to use Selenium-RC whenever your test requires logic not supported by Selenium-IDE. What logic could this be? For example, Selenium-IDE does not directly support

condition statements
iteration
logging and reporting of test results
error handling, particularly unexpected errors
database testing
test case grouping
re-execution of failed tests
test case dependency
screenshot capture of test failures

FitNesse with Selenium using Generic Fixture

You can download latest fitnesse.jar file from http://fitnesse.org/FitNesseDevelopment.DownLoad
And then Create a folder under C:/Program Files/Fitnesse/
Copy fitnesse.jar file and paste into C:/Program Files/Fitnesse/ folder.

Double click on " fitnesse.jar " file it will install itself.

Download Selenium Remote Control

Selenium-RC can be downloaded from http://seleniumhq.org/download/

Unzip the downloaded Selenium-RC into C:/Porgram Files/Selenium/ folder.

Create a start script for Selenium and Fitnesse

Open text file and Copy the following code into it and save the text file as Selenium.vbs

Function IsProcessRunning( strServer, strProcess )

Dim Process, strObject

IsProcessRunning = False

strObject = "winmgmts://" & strServer

For Each Process in GetObject( strObject ).InstancesOf( "win32_process" )

If UCase( Process.name ) = UCase( strProcess ) Then

IsProcessRunning = True

Exit Function

End If

End Function

sServer = "." ' "." for local machine

Set objShell = WScript.CreateObject("WScript.Shell")

Set objEnv = objShell.Environment("Process")

Selenium = "java -jar selenium-server.jar -browserSessionReuse -proxyInjectionMode"

If( IsProcessRunning( sServer, Selenium ) = False ) Then

objshell.CurrentDirectory =_

"C:\Program Files\Selenium\selenium_1_0_3\selenium-server-1.0.3"

result = objshell.Run ( Selenium, 5, true )

End If

Wscript.Quit

Open text file and Copy the following code into it and save the text file as Fitnesse.vbs

Function IsProcessRunning( strServer, strProcess )

Dim Process, strObject

IsProcessRunning = False

strObject = "winmgmts://" & strServer

For Each Process in GetObject( strObject ).InstancesOf( "win32_process" )

If UCase( Process.name ) = UCase( strProcess ) Then

IsProcessRunning = True

Exit Function

End If

End Function

sServer = "." ' "." for local machine

Set objShell = WScript.CreateObject("WScript.Shell")

Set objEnv = objShell.Environment("Process")

FitNesse = "java -cp fitnesse.jar fitnesse.FitNesse -p 8000"

If( IsProcessRunning( sServer, FitNesse ) = False ) Then

objshell.CurrentDirectory = "C:\Program Files\Fitnesse"

f = objshell.Run ( FitNesse, 6, false )

End If

Wscript.Quit

Download and Install Generic Fixture

You must have FitNesse framework installed on your computer and FitNesse server must be running on the computer where Generic Fixture is being installed.

You can download

Download the jar file genericfixture.jar containing full source code and compiled classes from Generic Fixture Sourceforge Site. Included classes have been generated using Sun’s JDK 1.5 Java compiler. Should you need to build Generic Fixture with any other JVM then make sure to put fitnesse.jar and fitlibrary.jar (provided in all the Fitnesse releases) in your CLASSPATH.

Install the Generic Fixture

Save genericfixture.jar somewhere on your computer where FitNesse server is running. Then simply add genericfixture.jar in your classpath on FitNesse Wiki. eg:

!path /path/to/download/dir/genericfixture.jar

Run startup script

Run the startup scripts Selenium.vbs and Fitnesse.vbs files which will start the both the servers.

Now you are about to run your own fitnesse scripts.......

Selenium IDE Useful Commands

noreply@blogger.com (kareem) — Thu, 16 Dec 2010 03:50:00 -0800

Selenium IDE is an integrated development environment for Selenium scripts. It is implemented as a Firefox extension.

Selenium IDE allows you to record, edit, and debug tests.

Selenium IDE can be downloaded from http://seleniumhq.org/download/

Recording any action on a page will be done using commands known as Selenese Commands.

Most common Commands used as follows:

verifyTextPresent

Verifies that text appears on the page. It can be dynamic text that was loaded with ajax. If it’s on the page in the active window at the time this command is called, it’ll find it.

verifyValue

Verifies the value of an input field. Provide the id of the input as the target and the value is the text you’re expecting.

click

Tells the test to click something on the page. The target can be referenced with the element ID or xPath as with the other commands.

clickAndWait

This command is useful for form submissions. Many times when you’re in record mode and click a submit button, selenium will only record a “click” command. This will break your test commands following the form submission where you verify the presence of a success message or form values because the next page hasn’t loaded yet. The “wait” portion will wait to continue the testing when the next page has fully loaded.

select

select an option in a select box by providing the id of the select box and the option value.

verifyAttribute

Useful for checking the attributes (attributes such as class, style, href and anchor tags) for specific url.

To verifyAttribute first thing you need to do is viewXpath by right clicking on particular attribute.

Xpath catcher is an add-on for firefox to viewXpath. You can download Xpath catcher from https://addons.mozilla.org/en-US/firefox/addon/1095/?id=1095

Steps to find Xpath

1.Right click on attribute and select viewXpath

2.Copy the Xpath in target field of the Selenium IDE

3.Edit the xpath copied as follows

For example you have xpath as id('p_13872472-main_story')/x:div/x:div/x:h3/x:a

You have to edit in the following manner for verifying class attribute

//div[@id='p_13872472-main_story']/div/div/h3/a/@class