Simple Client

/* this is simple client program in java connecting server 127.0.0.1(localhost) with port no 8000 */

//regular import

import java.net.*;
import java.io.*;

public class client
{

Socket cli;
DataInputStream din;
DataOutputStream dos;

public void start()
{
try
{

cli=new Socket("127.0.0.1",8000);
din=new DataInputStream(cli.getInputStream());
dos=new DataOutputStream(cli.getOutputStream());
dos.writeUTF("hello server...........");
String str=din.readUTF();
System.out.println(str);
cli.close();
}
catch(Exception e)
{
System.out.println(e);
}

}
public static void main(String args[])
{
client c;
c=new client();
c.start();
}
}

Simple Server

/* This is simple server program in java running with port no 8000 */

import java.net.*;
import java.io.*;
public class server
{
ServerSocket ss;
Socket c;
DataInputStream din;
DataOutputStream dos;
public void start()
{
try{
ss=new ServerSocket(8000);
c=ss.accept();
din=new DataInputStream(c.getInputStream());
dos=new DataOutputStream(c.getOutputStream());
String str=din.readUTF();
System.out.println(str);
dos.writeUTF("hello client........");
c.close();
}
catch(Exception e)
{
System.out.println(e);
}
}
public static void main(String args[])
{
server ser;
ser=new server();
ser.start();
}
}