1.客戶端

package Thread;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.Socket;
import java.net.UnknownHostException;
 
import java.util.Scanner;

public class Click {
    
    public static void main(String[] args) throws UnknownHostException, IOException {
        
        Click click=new Click();
        click.start();
    }
    
    private Socket socket;
    public Click() throws UnknownHostException, IOException {
        socket
 
=new Socket("localhost", 8088);//連接指定的地址和端口
        
    }
    
    public void start() throws IOException {
        System.out.println("歡迎你，"+socket.getInetAddress());
        PrintWriter pw=null;
        //創建一條線程讀取 服務器端發送過來的信息。
        Thread t=new Thread(new ServerHandler());
        t.setDaemon(true);//
 
守護線程
        t.start();
        
        try {
            // 輸出流，將客戶端的消息發送出去
             pw=new PrintWriter(new OutputStreamWriter(socket.getOutputStream(),"utf-8"),true);
             
             Scanner scan=new Scanner(System.in);
             while(true){     
                    pw.println(scan.nextLine());    
                    }
        
        } catch (UnsupportedEncodingException e) {
            System.out.println("io流異常");
        } finally {
            if(socket!=null) {
                socket.close();
            }
        }
    }
    
    //讀取服務端發送的消息
    class ServerHandler implements Runnable{

        public void run() {
            BufferedReader br=null;
            try {
                br=new BufferedReader(new InputStreamReader(socket.getInputStream(), "utf-8"));
                System.out.println(br.readLine());
            
            } catch (IOException e) {
                System.out.println("IOException");
            }    
        }
    }    
}

2.服務端

package Thread;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Server {
    
    public static void main(String[] args) throws IOException {
        Server server=new Server();
        server.start();
    }
    
    //成員變量
    private ExecutorService threadPool;
    private ServerSocket serverSocket;
    private List<PrintWriter>allOut;
    
    public Server() throws IOException {//初始化變量
        serverSocket=new ServerSocket(8088);
        threadPool=Executors.newFixedThreadPool(3);
        allOut=new ArrayList<PrintWriter>();
    }
    
    public void start() {
    
        try {
            while(true) {
                System.out.println("等待客戶端連接");
            Socket socket=serverSocket.accept();//監聽客戶端的連接
            //每連接一條線程
            threadPool.execute(new ClickHandler(socket));
            }
        } catch (IOException e) {
            System.out.println("socket Exection");
        }
    }
    
    
    class ClickHandler implements Runnable{
        private Socket socket;
        public ClickHandler(Socket socket) {
            this.socket=socket;
        }
        //線程同步
        public synchronized void addOut(PrintWriter pw) {
            allOut.add(pw);
        }
        public synchronized void pwClose(PrintWriter pw) {
            pw.close();
        }
        
        public void run() {
            
            BufferedReader br;
            PrintWriter pw=null;
            try {
                System.out.println(socket.getInetAddress()+"連接成功");
                br = new BufferedReader(new InputStreamReader(socket.getInputStream(), "utf-8"));
                //使用輸出流將信息發到客戶端
                 pw=new PrintWriter(new OutputStreamWriter(socket.getOutputStream(),"utf-8"), true);
                addOut(pw);
                String message=null;
                while((message=br.readLine())!=null) {    
                        for(PrintWriter p:allOut) {
                            if(p!=pw) {
                                p.println(socket.getInetAddress()+":"+message);
                            }
                        }
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } finally {
                pwClose(pw);
                if(socket!=null) {
                    try {
                        socket.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }

        }
    }
    
    
}

end

Socket通訊的簡單用法