JAVA

Accessing Database in Java Servlet and JDBC Connection

2013-09-10T05:50:00.001-07:00

 Here we are going to show how to access Database in case of Servlets very effective way

you can do insertion,updation in similar manner.

// Loading libraries that we will use
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
 
public class DatabaseAccess extends HttpServlet{
    
  public void doGet(HttpServletRequest request,
                    HttpServletResponse response)
            throws ServletException, IOException
  {
      // JDBC driver name, database URL,Username and password
      static final String JDBC_DRIVER="com.mysql.jdbc.Driver";  
      static final String DB_URL="jdbc:mysql://localhost/TEST";
      static final String USER = "root";
      static final String PASS = "password";

      // Set response 
      response.setContentType("text/html");
      PrintWriter out = response.getWriter();
      String title = "Database Result";
      String docType =
        "<!doctype html public \"-//w3c//dtd html 4.0 " +
         "transitional//en\">\n";
         out.println(docType +
         "<html>\n" +
         "<head><title>" + title + "</title></head>\n" +
         "<body bgcolor=\"#f0f0f0\">\n" +
         "<h1 align=\"center\">" + title + "</h1>\n");
      try{//Here see the steps for JDBC Connection in BOLD
         // Register JDBC driver
         Class.forName("com.mysql.jdbc.Driver");

         // Openning  a connection
         conn = DriverManager.getConnection(DB_URL,USER,PASS);

         // Executing  SQL query
         stmt = conn.createStatement();
         String sql;
         sql = "SELECT id, first, last, age FROM Employees";
         ResultSet rs = stmt.executeQuery(sql);

         // Extracting data from result set
         while(rs.next()){
            //Retrieve by column name
            int id  = rs.getInt("id");
            int age = rs.getInt("age");
            String name = rs.getString("name");
           

            //Display values
            out.println("ID: " + id + "<br>");
            out.println(", Age: " + age + "<br>");
            out.println(", name: " + name + "<br>");
           
         }
         out.println("</body></html>");

         // Clean-up environment
         rs.close();
         stmt.close();
         conn.close();
      }catch(SQLException se){
         //Handle errors for JDBC
         se.printStackTrace();
      }catch(Exception e){
         //Handle errors for Class.forName
         e.printStackTrace();
      }finally{
         //finally block used to close resources
         try{
            if(stmt!=null)
               stmt.close();
         }catch(SQLException se2){
         }
         try{
            if(conn!=null)
            conn.close();
         }catch(SQLException se){
            se.printStackTrace();
         }
      }
   }
}

Types of JDBC Connection In Java

2013-09-10T05:38:00.002-07:00

JDBC Connection is a connection pool in order to interact with the database whether simple or distributed database.
There are 5 types of Jdbc Driver:

1.JDBC-ODBC Driver:
Java Database Connectivity -Oracle Database Connectivity is a type 1 driver used in earlier times and now we use just used it for testing purposes.
Simple architecture where we have: Java Application calling>>JDBC API>>JDBC Driver Manager>>JDBC ODBC Bridge>>ODBC Driver>> Database Library API>>Database.
Overhead due to ODBC connection and ODBC need to be on client machine or need to install it.

2.Type 2 Driver- Native API Driver:
These Driver converts jdbc calls into native calls of the database apis.It is a database driven implementation that uses client side libraries of the database.
Simple Architecture Where we have:Java Application Calling>>JDBC API>>JDBC Driver Manager>>Native API Driver>>Database Library API>>Database.
IT is faster than Type 1 as there is no requirement for ODBC connection.
It is platform independent and support all application excepts applet.

3.Type 3 Driver Network Protocol Driver:
These driver is also known as pure java Driver for Database Middleware is a database driven implementation which makes use of middle tier between calling program and database.
The JDBC client driver written in java communicate with the net server using a database independent protocol then net server translates this into database command for fetching or update operation on database
Simple Architecture:
Java application call>>Java API>>JDBC Driver Manager>>Network Protocol Driver>>Middle ware>>Distributed Database.

4.Type 4 Driver Pure Java Driver:
Most importantly used by all the organization as it is a pure Java Driver that converts java calls into data specific calls and get required results with no pain and ease of use while connecting.
These Driver is Database Depentdent only drawback .
Simple Architecture:
Java application call>>Java API>>JDBC Driver Manager>>Network Protocol Driver>>Distributed Database.

5.Type 5 Driver :
IT is a new driver which eradicate the limitations of type 4 and hence 100% client side single tier .
It eliminates unrestricted performance,codeless enhancement,all in one deployment,resource efficiency.

What is Static Keyword?

2013-09-10T05:02:00.002-07:00

In Java,Static Keyword is associated with the class not with the instance of class.Therefore you can access static member without creating a class instance.
There are two types of static members in C++ and Java:
1.Static field:
The value of static field remains same for all the instance of the class.You can interchange the position of static keyword as per your need.Between the function calls its value remains same.
1.1Like: public static int a ;
1.2 static public int a;
Both the statement is same 1.1 and 1.2
If a class has static field StudentId all the objects within the class will have same value for StudentId in the program.It will help in counting the number of objects.
Static field will be accessed by classname.
classname.<static variablename>.

Static fields are created and initialized when the class is first loaded.

2.Static Method():
A method declares as static becomes static method which can access only static variables.
Static method is associated with the class not with the instance or object of the class.
Static method we see in our program that is main()which is called by the java runtime to execute an application.
In order to call static method:
classname.staticmethodname();///Sytax for call static method.

Simple Program in Showing USe of Static:
class A
{
int a =10;
static int b=10;
void display()
{a=a+a;
b=b+b;
System.out.println("a");
System.out.println("b");
}
}
public class C
{
public static void main(String args[])
{
A d=new A();
d.display();
A e=new A();

e.display();
}

OUTPUT:
20
20
20
40

System.out.Println Java

2013-09-10T04:24:00.002-07:00

We usually use many or dozen of times but do we really know what it is.
System.out.println() just prints the argument passed into the System.out.

System.out.println():
1.System: It is a final class and cannot be inherited .For further know-how refer to javadocs.
2.out: It is of type PrintStream and static menber of System Class.The Access specifiers for it is public final.
3.println():As braces itself says that it is a function that print whatever pass to it in the standard console.
Every println makes a call to print method and print calls to write method .

A simple program to print Hello using System.out.println():
class a
{
public static void main(Strings args[])
{
System.out.println("Hello") ;
}
}
Compile:javac a.java
run:java a

Java Projects Java Assignment

2013-05-17T04:14:00.000-07:00

Java is not a language it is technology when we talk about java we should know what we can do through Java,how prowerful and secure it is and what constraints and checkpoints we can add to our Webapp,Software or mobile apps in an effective manner.
Java is having three main Edition:
1.Java 2 Standard Edition: (J2SE)
What we can make and Learn in this through this we can make an standalone program like an inventory system or tracking system for a shop,offfice or any manufacturing industry.Simple Standalone application that we can make by using Swing,JDBC and Sqlite as required for our initial Project.
2.Java 2 Enterprise Edition:(J2EE)
When we talk about Enterprise Edition we are mostly talking ERP for a Company,Any Web Based management project by using mutli layer and in depth architecture for development.Here generally we talk about HTML,CSS,Javascript For GUI,JSP,Servlet,Struts,Spring,Design Patterns,Php In java,Ruby in Java and mobile based customization so to have more value to our project.
Simply it is an online Meeting System,Online Banking Management Project etc as this project requires to think in more depth manner by keeping in mind security as first Priority.
Here We can Use Various CMS like Sharepoint,Hippo,OpenCMS,Liferay etc.
3.Java 2 Micro Edition:(J2ME):JAVAME
We are talking about here our mobile portion and there connection with server in order to develop our mobile games,mobile apps for fun and learning,for security purposes.
It include each and every section of mobile part and developing it more securily by using Java Technology in an meaningful manner.For Set-top boxes,blu-ray Disc Players etc.
Here we generally use:Java ,SQlite,XML,python etc.

FOR Project or Assignment Help You can contact to our Java Experts at LearnProgramm@gmail.com.
https://www.google.co.in
https://www.yahoo.com
https://www.twitter.com
https://www.Facebook.com
https://www.w3schools.com
https://www.youtube.com

prime in java

2011-08-22T01:16:00.001-07:00

to calculate whether the number is prime or not.prime in java
javalearing.blogspot.com
class prime
{
public static void main(String args[])
{

int num=11;
int i;
for( i=2;i<num;i++)
{
int n=num%i;
if(n==0)
{
System.out.println("not prime");
break;
}
}
if(i==num){
System.out.println("prime number");
}
} }

package implementation in java

2011-08-22T00:40:00.001-07:00

javalearing.blogspot.com
Here we will show u a simple program of packages and its implementation.
first create a package naming pack(any name)then create class and its method should be static and public as shown below:

package pack;
public class hemant
{
public static void show(String s)
{
System.out.println(s);
}
}
save above as hemant.java
now compile your file as: javac hemant.java
now make another file in which you wanted to import your package for example demo.java

import pack.hemant; //for importing package pack having class name hemant
class demo
{
public static void main(String args[])
{
hemant.show("hi bye");
}
}
save above as demo.java
compile your package class first: javac hemant.java
compile your another file create by you: javac demo.java
run your demo file:java demo
output:
hi bye
finally you get the clear concept of packages.

A JAVA PROGRAM SHOWING OBJECTS AND ITS CLASS IMPLEMENTATION

2011-08-22T00:26:00.000-07:00

HERE WE HAVE BOX AS A CLASS WITH WIDTH,HEIGHT AND DEPTH AS ATTRIBUTES AND VOLUME AS METHOD.PROGRAM IS SELF EXPLAINATORY.
class box
{
double width;
double height;
double depth;

public void volume()
{
System.out.println("volume is ");
System.out.println(width*height*depth);
}
}
class boxdemo
{
public static void main(String args[]){
box mybox1=new box();
box mybox2=new box();
mybox1.width=100;
mybox1.height=20;
mybox1.depth=10;
mybox2.width=3;
mybox2.height=6;
mybox2.depth=7;
mybox1.volume();
mybox2.volume();
}
}

NOTEPAD OPENING USING JAVA

2011-08-22T00:20:00.001-07:00

QUESTION:NOTEPAD OPENING USING JAVA:
Here we use ProcessBuilder class and create its object following is a simple program opening notepad using java.
import java.io.*;
import java.util.*;
class notepad
{
public static void main(String args[])
{

try
{
ProcessBuilder proc=new ProcessBuilder("notepad.exe","report");
proc.start();
}
catch (Exception e)
{
System.out.println("notepad not open");
}

}
}

JAVA PROGRAM TO IMPLEMENT COLOR SECTIONS

2011-04-28T01:29:00.001-07:00

www.javalearing.blogspot.com importjava.awt.*;

import java.awt.event.*;
import java.applet.*;
 
public class fillcolor extends Applet implement Item Listener
{
 checkbox red,yellow,black,blue,orange;
 CheckboxGroup cbg;
 String msg;
 String s1="red";
 String s2="yellow";
 String s3="black";
 String s4="orange";
 public void init()
 {
  cbg = new CheckboxGroup();
  red = new Chechbox("red",cbg,true);
  yellow= new Checkbox("yellow",cbg,false);
  black = new Checkbox("black",cbg,false);
  blue = new Checkbox("blue",cbg,false);
  orange = new checkbox("orange".cbg.false);
  add(red);
  add(yellow);
  add(black);
  add(blue);
  add(orange);
  red.addItemListener(this);
  yellow.addItemListener(this);
  black.addItemListener(this);
  blue.addItemListener(this);
  orange.addItemListener(this);
 }
 publice void itemStartechanged(ItemEvent ie)
 {
  repaint();
 }
 publice void paint (Graphics g)
 {
  msg = cbg.getSelectedCheckbox().getLabel();
  if(msg.compareTo(s1)==0)
  { 
      setBackground(Color.red);
  }
  else if (msg.compareTo(s2)==0)
  {
      setBackground(Color.yellow);
  }
  else if(msg.compareTo(s3)==0)
  {
      setBackground(color.black);
  }
  else if (msg.compareTo(s4)==o)
  {
      setBackground(Color.blue);
  }
  else
  {
      set Background(Color.orange);
  }
 }
}

Java 2: The Complete Reference, Fifth Edition

JAVA PROGRAM TO DISPLAY IP ADDRESSSOF A PARTICULAR HOST

2011-04-28T01:26:00.001-07:00

WWW.JAVALEARING.BLOGSPOT.COM

Head First Design Patterns

import java.net.*;
import java.io.*;
 
public class ip_host
{
 public static void main(String args[]) throws Exception
 {
  System.out.println("Enter the host name :");
  String n=new DataInputStream(System.in).readLine();
 
  InetAddress ipadd =InetAddress.getByName(n);
 
  System.out.println("IP address :"+ipadd);
 }
}

Head First Java, 2nd Edition

JAVA PROGRAM TO DISPLAY DOMAIN NAME SERVICE

2011-04-28T01:25:00.001-07:00

import java.net.*;
 
class dns
{
 public static void main(String args[]) throws Exception
 {
  try
  {
   InetAddress[] address=InetAddress.getAllByName("java.sun.com");
   for(int j=0;j<address.length;j++)
   System.out.println(address[j]);
  }
 
  catch(Exception e)
  {
   System.out.println("Error in accessing Internet :"+e);
  }
 }
}

MINIMUM OF TWO NUMBER USING CONDITIONAL OPERATOR

2011-04-28T01:06:00.001-07:00

class Minof2{
 public static void main(String args[]){
  //taking value as command line argument.
  //Converting String format to Integer value
  int i = Integer.parseInt(args[0]);
  int j = Integer.parseInt(args[1]);
  int result = (i<j)?i:j;
  System.out.println(result+" is a minimum value");
 }
}

PROGRAM TO PRINT SMALLEST AND LARGEST INTEGER

2011-04-28T01:05:00.000-07:00

/* Write a program that will read a float type value from the keyboard and print
   the following output.
   ->Small Integer not less than the number.
   ->Given Number.
   ->Largest Integer not greater than the number.
 */
class ValueFormat{
 public static void main(String args[]){
  double i = 34.32; //given number
  System.out.println("Small Integer not greater than the number : "+Math.ceil(i));
  System.out.println("Given Number : "+i);
  System.out.println("Largest Integer not greater than the number : "+Math.floor(i));
 }
}

Write a program to generate 5 Random nos. between 1 to 100

2011-04-28T01:03:00.001-07:00

/*Write a program to generate 5 Random nos. between 1 to 100, anD it
  should not follow with decimal point.
 */
class RandomDemo{
 public static void main(String args[]){
  for(int i=1;i<=5;i++){
   System.out.println((int)(Math.random()*100));
  }
 }
}

A PROGRAM TO DISPLAY MESSAGE ACCORDING TO MARKS OBTAINED.

2011-04-28T01:02:00.001-07:00

/* Write a program to display a greet message according to
   Marks obtained by student.
 */
class SwitchDemo{
 public static void main(String args[]){
  int marks = Integer.parseInt(args[0]); //take marks as command line
  argument.
   switch(marks/10){
    case 10:
    case 9:
    case 8:
     System.out.println("Excellent");
     break;
    case 7:
     System.out.println("Very Good");
     break;
 
 
    case 6:
     System.out.println("Good");
     break;
    case 5:
     System.out.println("Work Hard");
     break;
    case 4:
     System.out.println("Poor");
     break;
    case 3:
    case 2:
    case 1:
    case 0:
     System.out.println("Very Poor");
     break;
    default:
     System.out.println("Invalid value Entered");
   }
 }
}

TO FIND SUM AND PRODUCT OF A GIVEN DIGIT

2011-04-28T01:01:00.000-07:00

class Sum_Product_ofDigit{
 public static void main(String args[]){
  int num = Integer.parseInt(args[0]); //taking value as command line
  argument.
   int temp = num,result=0;
  //Logic for sum of digit
  while(temp>0){
   result = result + temp;
   temp--;
  }
  System.out.println("Sum of Digit for "+num+" is : "+result);
  //Logic for product of digit
  temp = num;
  result = 1;
  while(temp > 0){
   result = result * temp;
   temp--;
  }
  System.out.println("Product of Digit for "+num+" is : "+result);
 }
}

FACTORIAL OF A GIVEN NUMBER

2011-04-28T01:00:00.001-07:00

class Factorial{
 public static void main(String args[]){
  int num = Integer.parseInt(args[0]); //take argument as command line
  int result = 1;
  while(num>0){
   result = result * num;
   num--;
  }
  System.out.println("Factorial of Given no. is : "+result);
 }
}

FOR REVERSING A NUMBER

2011-04-28T00:59:00.000-07:00

class Reverse{
 public static void main(String args[]){
  int num = Integer.parseInt(args[0]); //take argument as command line
  int remainder, result=0;
  while(num>0){
   remainder = num%10;
   result = result * 10 + remainder;
   num = num/10;
  }
  System.out.println("Reverse number is : "+result);
 }
}

TO GENERATE FIBONACCI SERIES

2011-04-28T00:58:00.000-07:00


FOR  Example :
  Input - 8
  Output - 1 1 2 3 5 8 13 21
 
class Fibonacci{
 public static void main(String args[]){
  int num = Integer.parseInt(args[0]); //taking no. as command line
  argument.
   System.out.println("*****Fibonacci Series*****");
  int f1, f2=0, f3=1;
  for(int i=1;i<=num;i++){
   System.out.print(" "+f3+" ");
   f1 = f2;
   f2 = f3;
   f3 = f1 + f2;
  }
 }
}

Write a program to Concatenate natural numbers up to given range using for Loop

2011-04-28T00:57:00.000-07:00


   Example:
   Input - 5
   Output - 1 2 3 4 5 */
class Join{
 public static void main(String args[]){
 
 
  int num = Integer.parseInt(args[0]);
  String result = " ";
  for(int i=1;i<=num;i++){
   result = result + i + " ";
  }
  System.out.println(result);
 }
}

Write a program to find sum of all integers greater than 100 and less than 200 that are divisible by 7

2011-04-28T00:56:00.000-07:00

* Write a program to find sum of all integers greater than 100 and
   less than 200 that are divisible by 7 */
class SumOfDigit{
 public static void main(String args[]){
  int result=0;
  for(int i=100;i<=200;i++){
   if(i%7==0)
    result+=i;
  }
  System.out.println("Output of Program is : "+result);
 }
}

DISPLAY MULTIPLICATION TABLE

2011-04-28T00:55:00.001-07:00

class MultiplicationTable{
 public static void main(String args[]){
  int num = Integer.parseInt(args[0]);
  System.out.println("*****MULTIPLICATION TABLE*****");
  for(int i=1;i<=num;i++){
   for(int j=1;j<=num;j++){
    System.out.print(" "+i*j+" ");
   }
   System.out.print("\n");
  }
 }
}

SWAPPING OF TWO VALUES THROUGH JAVA

2011-04-28T00:54:00.001-07:00

class Swap{
 public static void main(String args[]){
  int num1 = Integer.parseInt(args[0]);
  int num2 = Integer.parseInt(args[1]);
  System.out.println("\n***Before Swapping***");
  System.out.println("Number 1 : "+num1);
  System.out.println("Number 2 : "+num2);
  //Swap logic
  num1 = num1 + num2;
  num2 = num1 - num2;
  num1 = num1 - num2;
  System.out.println("\n***After Swapping***");
  System.out.println("Number 1 : "+num1);
  System.out.println("Number 2 : "+num2);
 }
}

Java program to convert given no. of days into months and days

2011-04-28T00:53:00.001-07:00

   (Assume that each month is of 30 days)
   Example :
   Input - 69
   Output - 69 days = 2 Month and 9 days */
class DayMonthDemo{
 public static void main(String args[]){
  int num = Integer.parseInt(args[0]);
  int days = num%30;
  int month = num/30;
  System.out.println(num+" days = "+month+" Month and "+days+" days");
 }
}