Java socket ， 服务端与客户端多线程交互

Socket服务端，用一个池对象来保存SocketServer接收到的socket链接。

实现过程中注意

接收客户端连接,只要客户端进行了连接,就会触发accept();从而建立连接。如下：
socket=serverSocket.accept(); 

此时需要new Handler(socket)一个对象，并将其放入线程池中。如下：
executorService.execute(new Handler(socket));

socket服务端，可做的内容如下：

1）根据与客户端约定好的数据格式，例如：数据的前4位代表userName，5-8位代表客户端请求服务端的methodName。等等，提供相应服务。

2）可以根据socket服务端机器的能力强弱，控制线程池大小。并提供实时的服务器链接数，从而让客户端用户能够选择压力较小的服务器进行链接。提供稳定流畅的服务。

3）可自己封装一个java.net.Socket类MySocket，在其对象里放入一个唯一标志例如客服端传递过来userName，进而实现一个userName，同时只能一个点连接上服务端。

下面是代码：

MultiThreadServer

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class MultiThreadServer {
    private int port=8888;
    private ServerSocket serverSocket;
    private ExecutorService executorService;//线程池
    private final int POOL_SIZE=5;//单个CPU线程池大小
    
    public MultiThreadServer() throws IOException{
        serverSocket=new ServerSocket(port);
        //Runtime的availableProcessor()方法返回当前系统的CPU数目.
        executorService=Executors.newFixedThreadPool(POOL_SIZE);
        System.out.println("服务器启动");
    }
    
    public void service(){
        while(true){
            Socket socket=null;
            try {
                //接收客户连接,只要客户进行了连接,就会触发accept();从而建立连接
                socket=serverSocket.accept();
                executorService.execute(new Handler(socket));
                
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    
    public static void main(String[] args) throws IOException {
        new MultiThreadServer().service();
    }

}

class Handler implements Runnable{
    private Socket socket;
    public Handler(Socket socket){
        this.socket=socket;
    }
    private BufferedOutputStream getWriter(Socket socket) throws IOException
    {
        OutputStream socketOut = socket.getOutputStream();
        BufferedOutputStream buff = new BufferedOutputStream(socketOut);
        return buff;
    }

    private BufferedInputStream getReader(Socket socket) throws IOException
    {
        InputStream socketIn = socket.getInputStream();
        return new BufferedInputStream(socketIn);
    }
    public String echo(String msg){
        return "echo:"+msg;
    }
    public void run(){
        try {
            System.out.println("New connection accepted "+socket.getInetAddress()+":"+socket.getPort());
            BufferedInputStream bis = getReader(socket);
            BufferedOutputStream bos = getWriter(socket);
            
            while (true)
            {
                byte[] sizeb = new byte[1024];
                bis.read(sizeb);
                // 根据于客户端约定好的数据格式，执行对应业务。
                System.out.println(new String(sizeb));
                
                String echo = " Hi " + socket.getInetAddress();
                byte[] response = echo.getBytes();
                
                bos.write(response); // 
                bos.flush();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            try {
                if(socket!=null)
                    socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    
}

由于我们项目的客户端是C#项目，所以我就直接copy了网络上的一个例子，如下：

ClientThread

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

class ClientThread implements Runnable
{

    Socket socket = null;

    int    id     = 0;

    public ClientThread(Socket socket, int id)
    {

        this.socket = socket;

        this.id = id;

    }

    @Override
    public void run()
    {

        OutputStream out = null;

        InputStream in = null;

        System.out.println("Begin to Chat to server...");

        try
        {

            out = socket.getOutputStream();

            in = socket.getInputStream();

            // 循环发送与服务端不停的交互数据

            while (true)
            {

                try
                {

                    Thread.sleep(1000);

                }
                catch (InterruptedException e)
                {

                    e.printStackTrace();

                }

                doWrite(out);

                System.out.println("begin read message from server.");

                doRead(in);

            }

        }
        catch (IOException e)
        {

            e.printStackTrace();

        }

        finally
        {

            try
            {

                in.close();

                out.close();

            }
            catch (IOException e)
            {

                e.printStackTrace();

            }

        }

    }

    /**
     * 
     * 读取服务端数据
     * 
     * @param in
     * 
     * @return
     */

    public static boolean doRead(InputStream in)
    {

        // 引用关系，不要在此处关闭流

        byte[] bytes = new byte[1024];

        try
        {

            in.read(bytes);

            System.out.println("line:" + new String(bytes).trim());

        }
        catch (IOException e)
        {

            e.printStackTrace();

        }

        return true;

    }

    /**
     * 
     * 发送数据到服务端
     * 
     * @param out
     * 
     * @return
     */

    public boolean doWrite(OutputStream out)
    {

        // 引用关系，不要在此处关闭流

        String line = "Hello server, I am client = " + id + "\n";

        line = line + "I want you to do something for me";

        try
        {

            out.write(line.getBytes());

            out.flush();

        }
        catch (IOException e)
        {

            e.printStackTrace();

        }

        return true;

    }

}

ClientMain

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

public class ClientMain
{

    public static void main(String[] args)
    {

        Socket socket = null;

        System.out.println("ClientSocket Begin........");

        try
        {

            for (int i = 0; i < 5; i++)
            {

                socket = new Socket("192.168.6.168", 8888);

                new Thread(new ClientThread(socket, i), "ClientThread " + i).start();

            }

        }
        catch (IOException e)
        {

            e.printStackTrace();
        }

    }
}