How Does Java Socket programming works

Learning Java Programming Made Easy


Java Socket Programming:

Java Socket programming is used for communication between the applications running on different JRE.Java Socket programming can be connection-oriented or connection-less. Socket and ServerSocket classes are used for connection-oriented socket programming and DatagramSocket and DatagramPacket classes are used for connection-less socket programming. The client in socket programming must know two information:

1. IP Address of Server, and
2. Port number.

A socket is simply an endpoint for communications between the machines. The Socket class can be used to create a socket.

Server-Side Program:

MyServer.java

1. import java.io.*;  
2. import java.net.*;  
3. public class MyServer {  
4. public static void main(String[] args){  
5. try{  
6. ServerSocket ss=new ServerSocket(6666);  
7. Socket s=ss.accept();//establishes connection   
8. DataInputStream dis=new DataInputStream(s.getInputStream());  
9. String  str=(String)dis.readUTF();  
10. System.out.println("message= "+str);  
11. ss.close();  
12. }catch(Exception e){System.out.println(e);}  
13. }  
14. } 

Client-Side Program:

MyClient.java

1. import java.io.*;  
2. import java.net.*;  
3. public class MyClient {  
4. public static void main(String[] args) {  
5. try{      
6. Socket s=new Socket("localhost",6666);  
7. DataOutputStream dout=new DataOutputStream(s.getOutputStream());  
8. dout.writeUTF("Hello Server");  
9. dout.flush();  
10. dout.close();  
11. s.close();  
12. }catch(Exception e){System.out.println(e);}  
13. }  
14. }