eProgrammingLab

Java Source Code


Java Source Code


1. Write a simple Hello World java program. 
package eprogramminglab;

public class HelloWorld
{
	public static void main (String[] args)
	{
		System.out.println("Hello World");
	}
} // End HelloWorld



Output: Hello World

2. Write a simple Hello World java program. 
public class HelloWorld
{
	public static int a=10; // Static (class level) variable
	public int b=20; // Non-static (class level, without static) variable
	int c=30; // Local variable
	
	public static void main (String[] args)
	{
		int lvl1 = 100;
		HelloWorld obj = new HelloWorld();
		// Static variable can be called directly
		System.out.println(a);
		// Non-static variable should be called by using object
		System.out.println(obj.b);
		// Local variable 
		System.out.println(obj.c);
		// Local variable 
		System.out.println(lvl1);
		
		
		System.out.println("M1: ");
		m1();
		System.out.println("M2: ");
		obj.m2();
		System.out.println("M3: ");
		m3();
		System.out.println("M4: ");
//		obj.m4();
		System.out.println("M5: ");
//		obj.m5();
		System.out.println("M6: ");
//		obj.m6();
	} // End main
	
	// Static method
	static void m1() {
		System.out.println("Static Method: ");
		
	} // End m1
	
	// Non static method
	void m2() {
		System.out.println("Nonstatic Method: ");
		
	} // End m2
	
	// Void method
	static void m3() {
		System.out.println("Void Method: ");
	
	} // End m3
	
	// Non void method
	static int m4(int val) {
		System.out.println("Nonvoid Method: ");
		int x = 5, y = 6;
		val = x*y;
		return m4(val);
	} // End m4
	
	// Parameterized method
	static int m5(int a, int b) {
		System.out.println("Parameterized Method: ");
		return m5(a, b);
	} // End m5
	
	// Non-parameterized method
	static int m6() {
		System.out.println("Nonparameterized Method: ");
		return m6();
	} // End m6
} // End HelloWorld



Output:

3. Write a simple program to call static method. 

package eprogramminglab;

public class EprogrammingLab
{
	public static int a = 10;
	public int b;
	
	public static void main (String[] args)
	{
		System.out.print("M1: ");
		m1();
	}
	
	static void m1()
	{
		System.out.println("Static Method:");
		System.out.print("a = " + a);
		EprogrammingLab obj = new EprogrammingLab();
		System.out.println(", b = " + obj.b);
	}
}
















package eprogramminglab;

public class EprogrammingLab
{
	public static int a = 10;
	int b;
	
	public static void main (String[] args)
	{
		EprogrammingLab obj1 = new EprogrammingLab();
		System.out.print("M1: ");
		obj1.m1();
	}
	
	void m1()
	{
		System.out.println("Calling Non Static Method:");
		System.out.print("a = " + a);
		EprogrammingLab obj2 = new EprogrammingLab();
		System.out.println(", b = " + obj2.b);
	}
}



Output:
M1: Static Method.
a = 10, b = 0

Q. Create a simple java program to show servlet to servlet communication. 
package com.Servlet2ServletCommunication;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class FirstServlet extends HttpServlet {
	
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
		
		res.setContentType("text/html");
		
		PrintWriter pw=res.getWriter();
		pw.print("
First Servlet
");
		
		RequestDispatcher rd=req.getRequestDispatcher("/second");
		//rd.forward(req, res);
		rd.include(req, res);
		
		
	}
	
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
		doPost(req, res);
	}
}







Output: 


package com.Servlet2ServletCommunication;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class SecondServlet extends HttpServlet {
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
		
		res.setContentType("text/html");
		
		PrintWriter pw=res.getWriter();
		pw.print("
Second Servlet
");
	}
	
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
			doPost(req, res);
	}
}


Output: 




  Servlet2ServletCommunication
 
 
 first
 com.Servlet2ServletCommunication.FirstServlet
 
 
 
 first
 /first
 
 
 
 second
 com.Servlet2ServletCommunication.SecondServlet
 
 
 
 second
 /second
 
 



Output: