Question

我目前正在java中实现一个多线程代理服务器，它将接受来自客户端的消息并将它们转发到另一个服务器，然后该服务器将确认消息的接收。但是，我很难这样做。有人能指出我做错了什么吗？感谢。

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

public class Client{

public static void main(String[] args)
{
    try
    {
        Socket client = new Socket(InetAddress.getLocalHost(), 6789);
        if(client.isBound())
        {
            System.out.println("Successfully connected on port 6789");
        }
        Scanner scanner = new Scanner(System.in);
        DataInputStream inFromProxy = new DataInputStream(client.getInputStream());
        DataOutputStream outToProxy = new DataOutputStream(client.getOutputStream());
        while(true)
        {
             String message;
                System.out.print("Enter your message: ");
                message = scanner.next();
                outToProxy.writeUTF(message);
                System.out.println(inFromProxy.readUTF());
        }
    }
    catch(IOException io)
    {
        System.err.println("IOException: " + io.getMessage());
        System.exit(2);
    }
    }
}

服务器代码Server.java：

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

/** 
 *  the client send a String to the server the server returns it in UPPERCASE thats all
 */

public class Server {

public static void main(String[] args)
{
    try
    {
        ServerSocket server = new ServerSocket(6780);
        if(server.isBound())
        {
            System.out.println("Server successfully connected on port 6780");
        }
        Socket client = null;
        while(true)
        {
            client = server.accept();
            if(client.isConnected())
            {
                System.out.println("Proxy is connected");
            }

            DataInputStream inFromProxy = new DataInputStream(client.getInputStream());
            DataOutputStream outToProxy = new DataOutputStream(client.getOutputStream());
            System.out.println(inFromProxy.readUTF());
            outToProxy.writeUTF("Message has been acknowledged!");
        }
    }
    catch(IOException io)
    {
        System.err.println("IOException: " + io.getMessage());
        System.exit(2);
    }
}
}   




import java.io.*;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.*;

public class Proxy{

    public static ServerSocket server = null;

    public static Socket client = null;


public static void main(String[] args)
{
try
{
    server = new ServerSocket(6789);
    Socket clientsocket = null;

    while(true)
    {
        client = server.accept();      

        if(client.isConnected())
        {
            System.out.println("Proxy is currently listening to client on port 6789");
        }
        clientsocket = new Socket(InetAddress.getLocalHost(), 6780);
        Thread t1 = new ProxyHandler(client, clientsocket);
        t1.start();


        if(clientsocket.isBound())
        {
            System.out.println("Clientsocket successfully connected on port 6780");
        }

        Thread t2 = new ProxyHandler(clientsocket, client);
        t2.start();                                                               

    }
}
catch(IOException io)
{
    System.err.println("IOException: " + io.getMessage());
}
}
}

代理服务器代码是：

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

public class ProxyHandler extends Thread {
private Socket socket;
private String message;
public ProxyHandler(Socket socket, Socket clientsocket)
{
    this.socket = socket;        
}

public void run()
{       
    message = "";
    try
    {
        DataInputStream in = new DataInputStream(socket.getInputStream());
        DataOutputStream out = new DataOutputStream(socket.getOutputStream());
        while(true)
        {
            message = in.readUTF();
            out.writeUTF(message);

            System.out.println(message);
        }
    }
    catch(IOException io)
    {
        System.err.println("IOException: " + io.getMessage());
        System.exit(2);
    }
}
}

Answer 1

这里没有多线程。应该有。每个接受的套接字应该在服务器和代理服务器的自己的线程中完全处理。
在创建和连接Socket之后立即测试isBound（）是没有意义的。它永远不会是假的。
在accept（）之后立即测试isConnected（）是没有意义的。它永远不会是假的。
服务器完成后必须关闭每个接受的套接字，即一旦它有EOS（read（）返回-1）。
代理还必须在完成后关闭每个已接受的套接字，同上。
任何类型的代理都应该只复制字节。它不应该假设数据的格式。不要使用readUTF（），使用count = read（byte []）和write（buffer，0，count）。这也意味着您不需要代理中的DataInput / OutputStreams。

多线程客户端服务器代理java

1 个答案: