日期:2014-05-20  浏览次数:20770 次

关于java socket的奇怪问题??
我最近在学习java socket 于是写了一个Server 和一个 Client的简单测试程序(下面会贴出代码),写完了之后,就找我另外的2个同学的笔记本电脑做测试。
我的电脑(A)作为服务器,其他2个同学的电脑(C,B)做客户端,前提:我们的笔记本电脑都用有线上网的,而且都能彼此ping的通的,这中情况下java socket程序运行正常。


当我们的笔记本都换成是无线上网的,并且都能彼此ping的通的,在这种情况下,他们(2个客户端)运行程序的时候就会出现
java.net.ConnectException: Connection timed out: connect这样的错误。


然后继续尝试,我的笔记本换成有线上网,他们2台机子是无线上网的,或者,我的是无线上网,他们的是有线上网,这2中情况java socket 程序都能正常运行(当然了,无线能ping通有线的电脑,而有线的电脑不能ping通无线的电脑)。

总的来说,就是客户端和服务端如果都是无线上网的话,那么java socket测试程序就不能正常通信,我想知道为什么,请大神赐教!!万分感激!!!!

下面是Server 和Client程序(这绝对是最简单的测试程序):
Server:
Java code

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

public class Server extends ServerSocket {
    private static final int SERVER_PORT = 10000;

    public Server() throws IOException {
        super(SERVER_PORT);

        try {
            while (true) {
                Socket socket = accept();
                new CreateServerThread(socket);
            }
        } catch (IOException e) {
        } finally {
            close();
        }
    }

    // --- CreateServerThread
    class CreateServerThread extends Thread {
        private Socket client;
        private BufferedReader in;
        private PrintWriter out;

        public CreateServerThread(Socket s) throws IOException {
            client = s;

            in = new BufferedReader(new InputStreamReader(client.getInputStream(), "GB2312"));
            out = new PrintWriter(client.getOutputStream(), true);
            out.println("--- Welcome ---");
            start();
        }

        public void run() {
            try {
                String line = in.readLine();

                while (!line.equals("bye")) {
                    String msg = createMessage(line);
                    out.println(msg);
                    line = in.readLine();
                }
                out.println("--- See you, bye! ---");
                out.close();
                in.close();
                client.close();
            } catch (IOException e) {
            }
        }

        private String createMessage(String line) {
            return "your input is:"+line;
        }
    }

    public static void main(String[] args) throws IOException {
        new Server();
    }
}


Client:
Java code

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

public class Client {
    private static Socket client;
    private static final int SERVER_PORT = 10000;
    private static BufferedReader in;
    private static PrintWriter out;
    private static String mesFormSer;

    public Client() throws Exception {
        client = new Socket("192.168.1.103", SERVER_PORT);//这里ip要看情况改

        BufferedReader sin = new BufferedReader(new InputStreamReader(System.in));
        in = new BufferedReader(new InputStreamReader(client.getInputStream()));
        out = new PrintWriter(client.getOutputStream(),true);
        
        System.out.println(in.readLine());
        String message = sin.readLine();
        while (!message.equals("Quit")) {

            out.println(message);
            this.mesFormSer = in.readLine();
            System.out.println(this.mesFormSer);
            message = sin.readLine();

        }
        in.close();
        out.close();
        sin.close();
        client.close();
    }

    public static void main(String args[]) {
        try {
            new Client();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}



------解决方案--------------------
这是传说中会出现的无线必须ping有线后,有线可以连几分钟,所以要用无线先ping下有线才能正常使用