package test; 
import java.net.*; 
import java.io.*; 
public class Server { 
   private ServerSocket ss; 
   private Socket socket; 
   private BufferedReader in; 
   private PrintWriter out; 
   public Server() 
   { 
      try 
         { 
            ss=new ServerSocket(10000); 
            while(true) 
                           { 
                              socket = ss.accept(); 
                              String RemoteIP = socket.getInetAddress().getHostAddress(); 
                              String RemotePort = ":"+socket.getLocalPort(); 
                              System.out.println("A client come in!IP:"+RemoteIP+RemotePort); 
                              in = new BufferedReader(new 
		                              InputStreamReader(socket.getInputStream())); 
                              String line = in.readLine(); 
                              System.out.println("Cleint send is :" + line); 
                              out = new PrintWriter(socket.getOutputStream(),true); 
                              out.println("Your Message Received!"); 
                              out.close(); 
                              in.close(); 
                              socket.close(); 
                              } 
            }catch (IOException e) 
                                             { 
                                                out.println("wrong"); 
                                       } 
            } 
         public static void main(String[] args) 
         { 
                     new Server(); 
         } 
      }; 
 
Client端程序: 
package test; 
import java.io.*; 
import java.net.*; 
 
public class Client { 
   Socket socket; 
   BufferedReader in; 
   PrintWriter out; 
   public Client() { 
               try 
                   { 
                      System.out.println("Try to Connect to 127.0.0.1:10000"); 
                      socket = new Socket("127.0.0.1",10000); 
                      System.out.println("The Server Connected!"); 
                      System.out.println("Please enter some Character:"); 
                      BufferedReader line = new BufferedReader(new 
 
                      InputStreamReader(System.in)); 
                      out = new PrintWriter(socket.getOutputStream(),true); 
                      out.println(line.readLine()); 
                      in = new BufferedReader(new InputStreamReader(socket.getInputStream())); 
                      System.out.println(in.readLine()); 
                      out.close(); 
                      in.close(); 
                      socket.close(); 
                  }catch(IOException e) { 
                         out.println("Wrong"); 
                  } 
             } 
               public static void main(String[] args) { 
                        new Client(); 
                } 
         };