Cara menggunakan soket java untuk melaksanakan sembang LAN

package com.server;
 
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
 
import com.client.RunClient;
 
public class RunServer {
    public static Socket socket=null;
    /**
     * 建立服务器被动连接
     * @throws IOException
     */
    public void startServer() throws IOException {
        //服务器接收数据
        ServerSocket serverSocekt=new ServerSocket(8888);
        System.out.println("服务器启动，等待连接...");
        //创建客户端线程
        RunClient rc=new RunClient();
        Thread rct=new Thread(rc);
        rct.start();
        
        
        //阻塞线程 监听端口建立socket会话
        RunServer.socket=serverSocekt.accept();
        
        
        //获取输入留
        InputStream is=socket.getInputStream();
        //将字节输入流转换成字符输入流
        InputStreamReader isr=new InputStreamReader(is);
        //将字符输入流装入带缓冲的输入流中
        BufferedReader br=new BufferedReader(isr);
        
        String str=null;
        while((str=br.readLine())!=null){
            System.out.print("输出信息："+str);
        }
        socket.shutdownInput();
        serverSocekt.close();
    }
}

package com.client;
 
import java.io.BufferedWriter;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;
 
import com.server.RunServer;
 
public class RunClient implements Runnable {
    
    @Override
    public void run() {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("1、主动连接\n2、被动等待");
        String sign=input.next();
        switch (sign) {
        case "1":
            try {
                System.out.println("输入服务器IP：");
                startClient(input.next());
            } catch (Exception e) {
                e.printStackTrace();
            }
            break;
        case "2":
            try {
                startClient();
            } catch (Exception e) {
                e.printStackTrace();
            }
            break;
            
        default:
            break;
        }
    }
    
    
    /**
     * 由已经建立的socket 进行连接反向连
     * @throws Exception 
     * @throws UnknownHostException 
     */
    public void startClient() throws Exception{
        
        while(true){
            try {
                if(RunServer.socket!=null){
                    break;
                }
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        
        
        // 与服务器建立连接
        Socket socket=new Socket(RunServer.socket.getInetAddress().getHostAddress(), 8888);
        System.out.println("连接建立成功...");
        
        //向服务器写入流
        OutputStream os=socket.getOutputStream();
        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(os));
        Scanner input=new Scanner(System.in);
        
        while(true){
            System.out.println("输入信息：");
            bw.write(input.next());
            bw.newLine();
            bw.flush();
        }
    }
    
    /**
     * 通过IP与服务器建立连接
     * @throws Exception 
     * @throws UnknownHostException 
     */
    public void startClient(String ip) throws Exception{
        // 与服务器建立连接
        Socket socket=new Socket(ip, 8888);
        System.out.println("连接建立成功...");
        
        //向服务器写入流
        OutputStream os=socket.getOutputStream();
        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(os));
        Scanner input=new Scanner(System.in);
        
        while(true){
            bw.write(input.next());
            bw.newLine();
            bw.flush();
        }
    }
}

package com.start;
 
import com.server.RunServer;
 
public class Go {
 
    public static void main(String[] args) throws Exception {
        // TODO Auto-generated method stub
        RunServer rs=new RunServer();
        rs.startServer();
    }
 
}