Kate Java

OCAJP - Java SE 8 Tutorial For Beginners & Professionals 2018

noreply@blogger.com (Kate Java) — Wed, 10 Jan 2018 14:52:00 +0000

If you are looking ahead to turning into a Java programmer, a certification from Oracle is the proper way to make certain that you stand out from the non-certified programmers in phrases of know-how and skills. Oracle’s Java Certifications are particularly esteemed inside the IT fraternity. Preparing for the certification exam requires a strategic method that may help the aspirant to master the language and its functions. Here is a step-by-step manual that elaborates on the numerous tiers within the training for OCAJP 8 [1Z0-808] Certification exam.

Before Preparation:

The preparations require dedication, effort, and time. Incorporate the steps stated right here part of your every day habitual via allocating a normal and fixed time spot that can be without problems observed. A right know-how of the English language is beneficial as there may be a giant repository of excessive great assets in this language. Unless you try the examination in Spanish, observe path materials in English.
The time taken to put together for the Java SE 8 (OCAJP – 1Z0-808) Certification examination can range depending on your Java programming understanding and revel in. For a more energizing with primary programming know-how, the appropriate time span for education is 2 months, if they spend a large amount of time in a day for the arrangements. For those with a reasonably desirable know-how and revel in Java, this time can be reduced to one month or maybe 15 days, relying on to your velocity of learning and time allotted for daily exercise. For an amateur who has certainly no concept about Java or Object Oriented Programming, the time required for gaining knowledge of can move up to 6 months since they must apprehend the ideas of programming after which flow on Java precise getting to know.

Steps for Preparation

Understand the syllabus

The number one step is to get the whole syllabus for the exam. This will provide you with an in-depth perception of the subjects that you need to cowl within the set time frame. A look at plan can be prepared primarily based on the wide variety of topics and time required to complete each phase. The OCAJP 8 certification exam curriculum includes these primary subjects:

Java Basics
Working with Java Data Types
Using Operators and Decision Constructs
Creating and Using Arrays
Using Loop Constructs
Working with Methods and Encapsulation
Working with Inheritance
Handling Exceptions
Working with Selected classes from the Java API

Collect more information about the exam format, a number of questions asked, exam duration, and the minimum percentage for passing which can help you while taking mock tests.

Collect Preparation Materials:

Once you are acquainted with the syllabus and the subjects, the following step is to accumulate beneficial assets. These ought to consist of books in addition to online resources.

OCAJP 8 Preparation Books (Study Guide)

Books are in all likelihood the best reliable and good study materials for Java aspirants. There are any numbers of accurate guides that permit you to study the various elements of the topics. Before you spend heaps on Java books, it is essential to identify the most relevant ones. The right books can enhance your information of Java.

The highly recommended Study Guides for OCAJP 8 Certification exam preparation is - OCAJP 8 (1Z0-808) Exam Practice Tests (MyExamCloud.com)

OCEJWCD 6 Tutorial: The servlet’s environment

noreply@blogger.com (Kate Java) — Thu, 20 Jun 2013 06:49:00 +0000

The OCEJWCD 6 is the new exam for Java EE web component developers. This tutorial explains “The servlet’s environment” exam topic in detail with code examples.

Disclaimer : The contents are taken from free resources available on web including Oracle site and Wikipedia.

Servlets communicate with web users over a request response pattern executed by the servlet container. HTTP protocol can process the request−response pattern. Servlet container is essentially a part of a web server that interacts with the servlets.

The servlet container is used for managing other features of the servlet lifecycle. This article shows how to communicate with Servlets. And also understand the HTTP protocols, HTML forms, HttpServlet, related APIs and sample program to manage client sessions and cookies.

HTTP protocol

Understand more details of the HTTP protocol
Hypertext Transfer Protocol is a stateless protocol. Generally this HTTP protocol is used to transfer the HTML and other information. Uniform Resource Locator (URL) is a universal address for the HTML documents and other resources. This HTTP is belongs to the application layer.
Initially the client creates a connection to HTTP server. The HTTP client sends a message based on the HTTP standard (HTTP Request) and then waits for the answer. Server answers in the form of HTTP response to the client. HTTP client read the response. Then close/release the connection from the server.

Example client request

Request Line	:	GET /images/help.jpg HTTP 1.1
Header	:	Connection : Keep-Alive
		Referrer : http://localhost:8080/index.html
		User-Agent : Mozilla/4.0
		Host : nplus1.net
		Content-Type : application/x-www-form-urlencoded
		Content-Length : 28
		Body : name=images&value=bar

Example server response

Status Line HTTP/1.1 200 OK

Header	:	Date : Mon, 10 June 2013 06:04:34 GMT
		Server : Apache/2.4.4
		Content-Type : text/html
		Content-Length : 2456
		Last-Modified : Mon, 10 June 2013 02:43:45 GMT
Body	:	<html>
		<header><title>Welcome Image</title>
		.....
		</html>

Types of HTTP Request

Following HTTP types used for perform some actions
HEAD - requests header information.

GET - retrieves a single resource
POST – Send the client information to server.
PUT - Send a resource to be stored on the server.
DELETE - removes resource from specified URL.
TRACE - returns the entire network route from client to server and back.
OPTIONS - returns list of server's supported HTTP methods.
CONNECT - Converts the request connection to a transparent TCP/IP tunnel.
PATCH - Is used to apply partial modifications to a resource.

HTML forms

Understand fundamentals of HTML forms

HTML Page Structure

A HTML page has global structure. The html page has two main element: 1. head and 2. body.
The Head element has following major parts:

HEAD element, TITLE element and Meta data.
The body element has following major fields: Identification element (class, id), Grouping element (span, p), Header element (H1, h3, h4...)

Simple HTML document:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<HTML>
<HEAD>
<TITLE>Welcome to Kate Java Tutorials</TITLE>
</HEAD>
<BODY>
<P>Simple HTML page document.</p>
</BODY>
</HTML>

HTML Form:

HTML form has following control types: buttons, checkboxes, radio buttons, menus, text input, file select and object controls.
HTML form control element has following attributes: accept, accept-charset, action, enctype, method, name and target
HTML form input element has following attributes: type, name, value, size, maxlength, checked, src.

Sample HTML Form :

<FORM action="http://katejava.com/exam/adduser" method="post">
<P>
First name: <INPUT type="text" name="firstname"><BR>
Last name: <INPUT type="text" name="lastname"><BR>
email: <INPUT type="text" name="email"><BR>
<INPUT type="radio" name="sex" value="Male"> Male<BR>
<INPUT type="radio" name="sex" value="Female"> Female<BR>
<INPUT type="submit" value="Send"> <INPUT type="reset">
</P>
</FORM>

HttpServlet and related APIs

Understand fundamentals of the HttpServlet and related APIs
The Servlet API consists of two packages: javax.servlet and javax.servlet.http. The base functionality is defined in the javax.servlet package whose classes and interfaces outline a generic, protocol-independent implementation.

Servlet API

javax.servlet
- Support generic, protocol-independent servlets
- Servlet (interface)
- GenericServlet (class)
- service()
- ServletRequest and ServletResponse
- Provide access to generic server requests and responses
javax.servlet.http
- Extended to add HTTP-specific functionality
- HttpServlet (extends GenericServlet )
- doGet()
- doPost()
- HttpServletRequest and HttpServletResponse
- Provide access to HTTP requests and responses

User-defined Servlets

Inherit from HttpServlet
- Override doGet() and doPost()
To handle GET and POST requests
- Have no main() method

HttpServlet must override at least one method, usually one of these:

doGet, if the servlet supports HTTP GET requests
doPost, for HTTP POST requests
doPut, for HTTP PUT requests
doDelete, for HTTP DELETE requests
init and destroy, to manage resources that are held for the life of the servlet
getServletInfo, which the servlet uses to provide information about itself

doGet() and doPost()

protected void doGet( HttpServletRequest req, HttpServletResponse resp)
protected void doPost(HttpServletRequest req, HttpServletResponse resp)

Sample HttpServlet

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class HelloWorld extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
out.println("<html>");
out.println("<head><title>hello world</title></head>");
out.println("<body>");
out.println("<big>hello world</big>");
out.println("</body></html>");
}

public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
doGet(req, res);
}
}

Servlet related APIs

For more information refer following documents

JavaTM Platform, Enterprise Edition 6 API Specification
http://docs.oracle.com/javaee/6/api/
What is servlet API in java?
http://wiki.answers.com/Q/What_is_servlet_API_in_java

Exam Simulator

Commercial Exam Simulator for OCEJWCD 6 Certification
MyExamCloud's OCEJWCD 6 Training Lab

OCEJWCD ( SCWCD 6) Web Component Developer Certification Exam

noreply@blogger.com (Kate Java) — Thu, 06 Jun 2013 12:45:00 +0000

The web component developer certification for Java EE is hotter than other exams. Oracle offers two certifications for web component developers one for Java EE 5 and another one for Java EE 6.

Read the full article here.

OCEJWCD 6 Tutorial: Introduction to JavaServer Pages (JSP)

noreply@blogger.com (Kate Java) — Fri, 31 May 2013 14:35:00 +0000

The 1Z0-899 Java EE 6 Web Component Developer Certified Expert Exam focus more on business tier components. This tutorial is one of the certification exam topics which gives attention into JavaServer Pages (JSP).

Read the full article: OCEJWCD 6 Tutorial: Introduction to JavaServer Pages (JSP)

OCEJWCD 6 Tutorials: Introduction to Java Servlets

noreply@blogger.com (Kate Java) — Wed, 22 May 2013 14:26:00 +0000

This tutorial is one of the certification exam topics which gives attention into Java Servlet Technology . This will help your preparation to pass the 1Z0-899 Java EE 6 Web Component Developer Certified Expert Exam.

Servlet is a Java class that supplies compatible mechanism used to extend the ability of a Web-server that can support dynamic content generation. A servlet can almost be considered an applet that runs on the server side. Servlet provides a platform-independent methods to build Web-based applications. Servlets is a highly efficient CGI programs written in Java. When a Servlet-capable Web server receives a request for a URL that corresponds to a Java Servlet, the server hands the request off to the Servlet for processing. The Servlet dynamically produces a response to the request (typically an HTML Web page) and sends it back to the requesting browser.

Describe web applications, CGI, and the role of Java

Java Web application:

Web application is an computer application which is then deployed on the web server, the user can access that application via the Internet or an intranet using a browser. Java has strong support for building web applications using Java Enterprise technology. A Java web application is a collection of HTML pages, XML files, webservices, servlets, JSPs Java classes and jars to create dynamic web project.

Java CGI - Common Gateway Interface:

CGI is a scripts to receive the request and generate a response for transferring dynamic information between server and client. A CGI program can be written in any language, including Java, that can be executed by your Web server. CGI programs are commonly used to add search engines, guest-book applications, database-query engines, interactive-user forums, and other interactive applications to Web sites. Most of the input to a CGI program is passed into it through environment variables.

Role of Java:

Following different roles are divided based on the Servlet performance. Receive the explicit data sent by the client, receive the implicit HTTP request data sent by the browser, Generate the results, Dispatch the explicit information to the client and Dispatch the implicit HTTP response data.

Describe benefits of Java servlet technology

The advantages of using servlets is their fast performance and ease of use combined with more power over traditional CGI (Common Gateway Interface). Traditional CGI scripts written in Java have a number of disadvantages when it comes to performance: When a HTTP request is made, a new process is created for each call of the CGI script. This overhead of process creation can be very system-intensive, especially when the script does relatively fast operations. Thus, process creation will take more time than CGI script execution. Java servlets solve this, as a servlet is not a separate process. Each request to be handled by a servlet is handled by a separate Java thread within the Web server process, omitting separate process forking by the HTTP daemon.

Simultaneous CGI request causes the CGI script to be copied and loaded into memory as many times as there are requests. However, with servlets, there are the same amount of threads as requests, but there will only be one copy of the servlet class created in memory that stays there also between requests.

The Web container calls the init()method. This method initializes the servlet and must be called before life of a servlet, the init()method is called only once.

After initialization, the servlet can service client requests. Each requestis serviced in its own separate thread. The Web container calls the service() method of the servlet for every request. The service()method determines the kind of request being made and dispatches it to an appropriate method to handle the request. The developer of the servlet must provide an implementation for these methods. If a request for a method that is not implemented by the servlet is made, the method of the parent class is called, typically resulting in an error being returned to the requester.
Finally, the Web container calls the destroy() method that takes the servlet out of service. The destroy() method, like init(), is called only once in the lifecycle of a servlet.

Create a simple Java Servlet

public class MyServlet extends HttpServlet {
public void doGet (HttpServletRequest req, HttpServletResponse res) {
....
}
}

Deployment descriptor (web.xml)

<web-app>
<servlet>
<servlet-name>MyServlet</servlet-name>
<servlet-class>samples.MyServlet</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>MyServlet</servlet-name>
<url-pattern>/MyApp</url-pattern>
</servlet-mapping>
...
</web-app>

Define three-tier architecture

3-Tier client-server architectures have 3 essential components:

A Client PC
An Application Server
A Database Server

3-Tier Architecture Considerations:

Client program contains presentation logic only
Less resources needed for client workstation
No client modification if database location changes
Less code to distribute to client workstations
One server handles many client requests
More resources available for server program
Reduces data traffic on the network

Define Model-View-Controller (MVC) architecture

One of the most common Design Patterns is Model-View-Controller (MVC). The model does all the computational work. It is input/output free. All communication with the model is via methods. The controller tells the model what to do. User input goes to the controller. The view shows results; it is a “window” into the model. The view can get results from the controller, or The view can get results directly from the model

The model, as usual, does all the computational work, and no Input / Output. The model can consist of multiple classes. The servlet class (the one that extends HttpServlet) acts as the controller. The servlet gives any relevant information from the user request to the model. The servlet takes the results and passes them on to the view. The view—that is, the HTML page that is returned to the user—is frequently created by JSP.

Model: The domain-speciﬁc representation of the information on which the application operates. The model is another name for the application logic layer (sometimes also called the domain layer). Application (or domain)logic adds meaning to raw data (e.g., calculating iftoday is the user’s birthday, or the totals, taxes and shipping charges for shopping cart items). Many applications use a persistent storage mechanism (such as a database) to store data. MVC does not speciﬁcally mention the resource management layer because it is understood to be underneath or encapsulated by the Model.

View: Renders the model into a form suitable for interaction, typically a user interface element. MVC is often seen in web applications, where the view is the HTML page and the code which gathers dynamic data for the page.

Controller: Processes and responds to events, typically user actions, and may invoke changes on the model and view

Best Oracle Java Certification & Training

noreply@blogger.com (Kate Java) — Sat, 18 May 2013 16:01:00 +0000

The most extensive honoured IT certification programs available through Oracle Certifications bring valuable, measurable rewards to Java associate, professionals, master and expert their careers. In this article, we will guide you about Oracle certifications for Java Java programming language and technology. Also it will enhance your basic knowledge and teach you how to get started.

Here some of the impotent guidelines and notes for the who attend the training and who want become certified in Java Programming Technologies.

Why Java Certification & Training

The main reasons for Java Certification & Training is employee skills not matched to coming demand for jobs. There are six major industries IT, Education, Financial services, Business services and Heath services will provide the job for the programmers. So most of the industries will require post-secondary education and training. The real battle for the skill was started for the employee.

Technical changes will create demand for the candidates highly educated and certified in developing Rich user interface, application performance and security, web applications, mobile and other embedded devices.
So certification gives the job seekers with additional qualification and having better changes of being employed. Which means holding the Oracle certification would improve their employment opportunities.

Oracle Java Training Overview

Java training classes - including Java SE 7 lessons - that can help get beginners up to speed on Java and help experienced users become experts in Java.

Training for Java SE Application Development

This section will guide you to OOPs principles and the Java Programming language, so you can code smarter and develop programs more quickly. Following area must you should need to be familiar.

Java SE 7 New Features
Java SE 7 Fundamentals
Java SE 7 Programming
Java Performance Tuning and Optimization
Developing Applications With the Java SE 6 Platform
Object-Oriented Analysis and Design Using UML

Training for Enterprise Development with Java EE

This level was designed to get you going with enterprise application development and help you become an expert on core Java EE technologies including Enterprise JavaBeans (EJB), Java Persistence API (JPA), Web Services, JavaServer Faces (JSF), JavaServer Pages (JSP).

Developing Applications for the Java EE 6 Platform
Web Component Development with Servlets & JSPs, Java EE 6 Developing
Web Applications using JSF Technologies
Business Component Development with EJB Technology, Java EE 6
Building Database Driven Applications with JPA
Developing Web Services Using Java Technology, Java EE 6
Architect Enterprise Applications with Java EE

Oracle Java Certification

Oracle certifications exams and brings you the recognition for your knowledge and skills in developing Rich user interface, application performance and security, web applications, mobile and other embedded devices. Following certification are currently available.

Oracle Entry level and Associate level certification

Oracle Certified Associate, Java SE 7 Programmer.
Oracle Certified Associate, Java SE 5/SE 6.

Oracle Professional level certification

Oracle Certified Professional, Java SE 5 Programmer
Oracle Certified Professional, Java SE 6 Programmer
Oracle Certified Professional, Java SE 7 Programmer
Oracle Certified Professional, Java EE 5 Web Component Developer
Oracle Certified Professional, Java EE 5 Web Services Developer
Oracle Certified Professional, Java EE 5 Business Component Developer
Oracle Certified Professional, Java ME 1 Mobile Application Developer

Oracle Master level certification

Oracle Certified Master, Java SE 6 Developer
Oracle Certified Master, Java EE 5 Enterprise Architect
Oracle Certified Master, Java EE 6 Enterprise Architect

Oracle Expert level certification

Oracle Certified Master, Java SE 6 Developer
Oracle Certified Master, Java EE 5 Enterprise Architect
Oracle Certified Master, Java EE 6 Enterprise Architect

Practice Exams for Oracle Java certification

Practice tests are one of the most effective ways candidates can prepare for Oracle certification exams. Before candidates attend the exams we must test their knowledge. So that's the only way they can know their weakness, How much they can score the marks on the examination. That’s why we need the practice exam.

I would prefer for my training and teaching, Epractize labs Java Certification mock exams really help candidates to self-assess their knowledge using realistic exam simulations. This training lab built on practice exam tools including: Basic and Advanced Session (knowledge level practice exam preferences), Certification Session (Prepare and got real time experience thing with simulated exams) and Quiz Mode (self check in the form of game or mind sport). And also EPractize Labs provide all Oracle certification with industrial standard.

Good luck and Be more competitive in the Job market