import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;
import java.net.ServerSocket;
import java.util.ArrayList;
import javax.swing.JOptionPane;
 
public class MyServer {
 
 public static ArrayList<Socket> socketlist = new ArrayList<Socket>();
 private static String port ;
 public static void main(String[] args) throws IOException
 {
 //彈出一個(gè)對(duì)話(huà)框輸入端口號(hào)
 port = JOptionPane.showInputDialog("input the port number: ");
 int ServerPort = new Integer(port).intValue();
 
 ServerSocket ss = new ServerSocket(ServerPort);
 System.out.println("Server is initializating...");
 while(true)
 {
 System.out.println("Server is waiting...");
 
 //此處將阻塞監(jiān)聽(tīng)
 Socket s = ss.accept();
 System.out.println("listening from: " + s.getInetAddress());
 socketlist.add(s);
 new Thread(new ServerThread(s)).start();
 }
 }
 
}
class ServerThread implements Runnable
{
 Socket s = null;
 BufferedReader br = null;
 public ServerThread(Socket s) throws IOException
 {
 this.s = s;
 br = new BufferedReader(new InputStreamReader(s.getInputStream()));
 }
 public void run()
 {
 try
 {
 String content = null;
 while( (content = readFromClient()) != null )
 {
 //播報(bào)每個(gè)客戶(hù)端數(shù)據(jù)
 for(Socket s : MyServer.socketlist)
 {
 PrintStream ps = new PrintStream(s.getOutputStream());
 ps.println(content);
 }
 }
 }
 catch (IOException io) 
 {
 io.printStackTrace();
 }
 }
 private String readFromClient()
 {
 try
 {
 return br.readLine();
 }
 catch (IOException io)
 {
 MyServer.socketlist.remove(s);
 System.out.println(s.getInetAddress() + " is disconnecting...");
 }
 return null;
 }
 
}

import java.net.Socket;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
 
public class MyClient {
 
 public static void main(String[] args) throws Exception
 {
 Socket s = new Socket("192.168.1.164", 30000);
 
 // new Thread to read content from server.
 new Thread(new ClientThread(s)).start();
 
 PrintStream ps = new PrintStream(s.getOutputStream());
 String line = null;
 BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
 while((line = br.readLine()) != null)
 {
 ps.println(line);
 }
 }
}
class ClientThread implements Runnable
{
 private Socket s = null;
 BufferedReader br = null;
 public ClientThread(Socket s) throws IOException
 {
 this.s = s;
 br = new BufferedReader(new InputStreamReader(s.getInputStream()));
 }
 public void run()
 {
 try
 {
 String content = null;
 while( (content = br.readLine()) != null)
 {
 System.out.println(content);
 }
 }
 catch (IOException io)
 {
 io.printStackTrace();
 }
 }
}