网络编程+多线程实现简单的聊天室功能

一：需求分析

1：聊天室：一个服务器，多个客户端，当一个客户端发送信息给服务器时，服务器会把

消息广播给其他的客户端用户。

2：服务器端，主线程一直处于阻塞状态，接受客户端请求，每当一个客户端发送请求过来

时，都会启动一个线程处理请求。

3：客户端，主线程负责向服务器通过控制台写数据，另外启动一个线程负责读取服务器端发送

过来的信息。

二：服务器端

/**
 * 
 */
package com.hlcui.socket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * @author Administrator
 * 
 */
public class MyServer {
    public static final int PORT = 8080;
    public static List<Socket> socketList = Collections
            .synchronizedList(new ArrayList<Socket>()); // 定义一个线程安全的list

    // 初始化
    public void init() {

        try {
            ServerSocket ss = new ServerSocket(PORT);
            System.out.println("服务已经启动，等待客户端连接...");
            // 主线程一直在监听端口
            while (true) {
                Socket s = ss.accept();
                InetAddress inet = s.getInetAddress();
                System.out.println(inet.getHostAddress()+"上线了");
                socketList.add(s);
                new Thread(new ServerThread(s)).start(); // 启动线程处理客户端请求
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        MyServer server = new MyServer();
        server.init();
    }
}

class ServerThread implements Runnable {
    private BufferedReader br;
    private Socket s;

    ServerThread(Socket s) throws IOException {
        this.s = s;
        br = new BufferedReader(new InputStreamReader(s.getInputStream()));
    }

    @Override
    public void run() {
        String line = null;
        while ((line = readClientContext()) != null) {
            System.out.println(line);
            // 将客户端数据广播出去(传递给每个客户端数据)
            for (Socket s : MyServer.socketList) {
                try {
                    PrintWriter pw = new PrintWriter(s.getOutputStream());
                    pw.println(line);
                    pw.flush();
                    //pw.close();  //这里的pw一定不能关闭
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    // 读取客户端数据
    private String readClientContext() {
        try {
            return br.readLine();
        } catch (IOException e) {
            MyServer.socketList.remove(s);
            System.out.println("读取客户端数据失败！");
        }
        return null;

    }

}

三：客户端

/**
 * 
 */
package com.hlcui.socket;

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

/**
 * @author Administrator
 * 
 */
public class MyClient {
    public static final String IP = "127.0.0.1";
    public static final int PORT = 8080;

    // 初始化
    public void init() {
        BufferedReader br = null;
        PrintStream ps = null;
        try {
            Socket s = new Socket(IP, PORT);
            // 启动线程读取服务器端发送的数据
            new Thread(new ClientThread(s)).start();
            // 控制台向服务器发送数据
            br = new BufferedReader(new InputStreamReader(System.in));
            ps = new PrintStream(s.getOutputStream());
            String line = null;
            while ((line = br.readLine()) != null) {
                ps.println(line);
            }
            ps.flush();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (ps != null) {
                ps.close();
            }
        }
    }

    public static void main(String[] args) {
        MyClient client = new MyClient();
        client.init();
    }

}

class ClientThread implements Runnable {
    private BufferedReader br;

    ClientThread(Socket s) {
        try {
            br = new BufferedReader(new InputStreamReader(s.getInputStream()));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        String line = null;
        try {
            while ((line = br.readLine()) != null) {
                System.out.println(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}