Java Socket多线程通信例子

MyServer.java

package codes17.MultiThread.server;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;

public class MyServer {
// 定义保存所有Socket的ArrayList
public static ArrayList<Socket> socketList = new ArrayList<>();

public static void main(String[] args) throws IOException {
ServerSocket ss = new ServerSocket(30000);
while (true) {
// 此行代码会阻塞，将一直等待别人的连接
Socket s = ss.accept();
socketList.add(s);
// 每当客户端连接后启动一条ServerThread线程为该客户端服务
new Thread(new ServerThread(s)).start();
}
}
}


ServerThread.java
package codes17.MultiThread.server;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;

// 负责处理每个线程通信的线程类
public class ServerThread implements Runnable {
// 定义当前线程所处理的Socket
Socket s = null;
// 该线程所处理的Socket所对应的输入流
BufferedReader br = null;

public ServerThread(Socket s) throws IOException {
this.s = s;
// 初始化该Socket对应的输入流
br = new BufferedReader(new InputStreamReader(s.getInputStream()));
}

public void run() {
try {
String content = null;
// 采用循环不断从Socket中读取客户端发送过来的数据
while ((content = readFromClient()) != null) {
// 遍历socketList中的每个Socket，
// 将读到的内容向每个Socket发送一次
for (Socket s : MyServer.socketList) {
PrintStream ps = new PrintStream(s.getOutputStream());
ps.println(content);
}
}
} catch (IOException e) {
e.printStackTrace();
}
}

// 定义读取客户端数据的方法
private String readFromClient() {
try {
return br.readLine();
}
// 如果捕捉到异常，表明该Socket对应的客户端已经关闭
catch (IOException e) {
// 删除该Socket。
MyServer.socketList.remove(s);
}
return null;
}
}


MyClient.java
package codes17.MultiThread.client;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;

public class MyClient {
public static void main(String[] args) throws Exception {
Socket s = new Socket("127.0.0.1", 30000);
// 客户端启动ClientThread线程不断读取来自服务器的数据
new Thread(new ClientThread(s)).start(); //
// 获取该Socket对应的输出流
PrintStream ps = new PrintStream(s.getOutputStream());
String line = null;
// 不断读取键盘输入
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
while ((line = br.readLine()) != null) {
// 将用户的键盘输入内容写入Socket对应的输出流
ps.println(line);
}
}
}


ClientThread.java
package codes17.MultiThread.client;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;

public class ClientThread implements Runnable {
// 该线程负责处理的Socket
private Socket s;
// 该线程所处理的Socket所对应的输入流
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;
// 不断读取Socket输入流中的内容，并将这些内容打印输出
while ((content = br.readLine()) != null) {
System.out.println(content);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}