Java - Simple Echo Server

This code snippet demonstrates a simple echo server. The Client sends the string "Hello World" to the server and the server echo's back the string to the client.

Client

1. import java.net.*;  
2. import java.io.*;  
3.   
4. class Client{  
5.   
6.     public static void main(String args[]){  
7.   
8.         try {  
9.             Socket skClient = new Socket( "127.0.0.1", 1234);  
10.               
11.             System.out.println( "Connected to server!!!");  
12.               
13.             OutputStreamWriter sWriter = new OutputStreamWriter(skClient.getOutputStream());  
14.             sWriter.write( "Hello World\n");  
15.             sWriter.flush();  
16.               
17.             InputStreamReader sReader = new InputStreamReader(skClient.getInputStream());  
18.             BufferedReader bReader = new BufferedReader(sReader);  
19.               
20.             String serverResponse = bReader.readLine();  
21.               
22.             System.out.println(serverResponse);  
23.               
24.         }  
25.         catch (Exception e){  
26.             System.out.println(e.getMessage());  
27.         }  
28.     }  
29. }  

Server

1. import java.net.*;  
2. import java.io.*;  
3.   
4. class Server{  
5.   
6.     public static void main(String args[]){  
7.         System.out.println( "Server started");  
8.           
9.         try {  
10.             ServerSocket skServer = new ServerSocket(1234);  
11.               
12.             while (true){  
13.                 Socket skClient = skServer.accept();  
14.                   
15.                 InputStreamReader sReader = new InputStreamReader(skClient.getInputStream());  
16.                 BufferedReader bReader = new BufferedReader(sReader);  
17.                   
18.                 String clientResponse = bReader.readLine();  
19.                   
20.                 System.out.println( "Sent from client: " + clientResponse);  
21.                   
22.                 OutputStreamWriter sWriter = new OutputStreamWriter(skClient.getOutputStream());  
23.                   
24.                 sWriter.write(clientResponse +  "\n");  
25.                 sWriter.flush();  
26.             }  
27.               
28.         }  
29.         catch (Exception e){  
30.             System.out.println(e.getMessage());  
31.         }  
32.     }  
33. }