Java源码：Socket编程

				1. Server program source 
				
				// Server.java 
				
				/** 
				* This a Socket Server program 
				* @version 1.0 1999/12/27 
				* @author Huang Jian-chang 
				**/ 
				
				import java.net.*; 
				import java.io.*; 
				
				public class Server 
				{ 
				ServerSocket server; 
				DataOutputStream output; 
				Socket socket; 
				public Server (){ 
				try{ 
				// create a server on port 5000 
				server=new ServerSocket(5000); 
				// display interactive informaion 
				System.out.println("Server created."); 
				System.out.println("waiting for client to connect on..."); 
				// waiting for client to connect on... 
				socket = server.accept(); 
				// client connected 
				System.out.println("client connected.\nShutdown!"); 
				output = new DataOutputStream(socket.getOutputStream()); 
				output.writeUTF("Welcome to Server.Bye!"); 
				output.close(); 
				server.close(); 
				} 
				catch(SocketException e){ 
				System.out.println(e.toString()); 
				e.printStackTrace(); 
				System.exit(1); 
				} 
				catch(IOException e){ 
				System.out.println(e.toString()); 
				e.printStackTrace(); 
				System.exit(1); 
				} 
				} 
				
				public static void main(String args[]){ 
				Server game=new Server(); 
				} 
				} 
				
				
				
				2. Application Client program source 
				
				// Client.java 
				/** 
				* This a Socket Client program 
				* @version 1.0 1999/12/27 
				* @author Huang Jian-chang 
				**/ 
				
				import java.io.*; 
				import java.net.*; 
				
				public class Client { 
				public static void main(String args[]) { 
				try{ 
				if (args.length != 1){ 
				System.out.println("USAGE: java Client servername"); 
				return; 
				} 
				String connectto= args[0]; 
				Socket connection; 
				// connect to server 
				if(connectto.equals("localhost")){ 
				connection=new Socket(InetAddress.getLocalHost(),5000); 
				
				} 
				else{ 
				connection=new Socket(InetAddress.getByName(connectto),5000); 
				} 
				DataInputStream input=new DataInputStream(connection.getInputStream()); 
				
				// read information from server 
				String info; 
				info = input.readUTF(); 
				System.out.println(info); 
				connection.close(); 
				} 
				catch(SecurityException e){ 
				System.out.println("SecurityException when connecting Server!"); 
				} 
				catch(IOException e){ 
				System.out.println("IOException when connecting Server!"); 
				} 
				} 
				
				} 
				
				
				
				3. Applet Client program source 
				// AppletClient.java 
				/** 
				* This a Socket Applet Client program 
				* @version 1.0 1999/12/27 
				* @author Huang Jian-chang 
				**/ 
				import java.applet.*; 
				import java.awt.*; 
				import java.io.*; 
				import java.net.*; 
				
				public class AppletClient extends Applet { 
				String info=""; 
				public void init(){ 
				try{ 
				
				String connectto = getCodeBase().getHost(); 
				Socket connection; 
				// connect to server 
				if(connectto.equals("localhost")){ 
				connection=new Socket(InetAddress.getLocalHost(),5000); 
				
				} 
				else{ 
				connection=new Socket(InetAddress.getByName(connectto),5000); 
				} 
				DataInputStream input=new DataInputStream(connection.getInputStream()); 
				
				// read information from server 
				info = input.readUTF(); 
				System.out.println(info); 
				connection.close(); 
				} 
				catch(SecurityException e){ 
				System.out.println("SecurityException when connecting Server!"); 
				info = e.toString(); 
				} 
				catch(IOException e){ 
				System.out.println("IOException when connecting Server!"); 
				info = e.toString(); 
				} 
				} 
				public void paint(Graphics g){ 
				g.drawString(info,20,20); 
				} 
				} 
				
				
				Html File AppletClient.html : 
				 
				 
				 
								code=AppletClient.class 
				width = 200 
				height = 200 
				> 
				 
				 
				 
				 
				
				
				4 steps to run the application 
				1. javac Server.java 
				2. javac Client.java 
				3. java Server 
				4. java Client localhost(or the computername in which the server is running)