Java网络编程之tcp的socket通信

1、客户端MyClient.java

import java.io.*;
import java.net.*;

public class MyClient
{
    public static void main(String[] args)throws Exception
    {
        Socket s = new Socket("192.168.1.1" , 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();11         // 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);
        }
    }
}

2、加入多线程，ClientThread.java

import java.io.*;
import java.net.*;

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();
        }
    }
}

 

3、服务器端MyServer.java

import java.net.*;
import java.io.*;
import java.util.*;

public class MyServer
{
    // 定义保存所有Socket的ArrayList
    public static ArrayList<Socket> socketList
        = new ArrayList<Socket>();
    public static void main(String[] args)
        throws IOException
    {
System.out.println("222222……");
        ServerSocket ss = new ServerSocket

(30000);
        while(true)
        {
System.out.println("服务器等待链接……");
            // 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();
        }
    }
}

 

4、为服务器端通信加入多线程

import java.io.*;
import java.net.*;
import java.util.*;

// 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 {
        System.out.println("4444444……");
        this.s = s;
        // 初始化该Socket对应的输入流
    String ip=s.getInetAddress().getHostAddress();
        System.out.println("ip地址为"+ip+"........connected!!!");
        br = new BufferedReader(new InputStreamReader(s.getInputStream(),
                "utf-8")); // 
    }

    public void run() {
        System.out.println("555555……");
        try {
            System.out.println("4444444……");
            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) {
                /*System.out.println("---"
                        + Arrays.toString(content.getBytes("utf-8")));*/
                System.out.println("---" +"客户端发来的数据为"+content);
                System.out.println("===============");
                // 遍历socketList中的每个Socket，
                // 将读到的内容向每个Socket发送一次
                for (Iterator<Socket> it = MyServer.socketList.iterator(); it
                        .hasNext();) {
                    Socket s = it.next();
                    try {
                        System.out.println("666666");
                        OutputStream os = s.getOutputStream();
                        os.write((content+"服务器反馈给客户端ok" + "\n").getBytes("utf-8"));
                        System.out.println("777777");
                    } catch (SocketException e) {
                        e.printStackTrace();
                        // 删除该Socket。
                        it.remove();
                        System.out.println(MyServer.socketList);
                    }
                }
            }
        } 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) {
            e.printStackTrace();
            System.out.println("客户端已经关闭！！！");
            // 删除该Socket。
            MyServer.socketList.remove(s); 
        }
        return null;
    }
}