关闭一个旧后新创建套接字连接导致拒绝 [英] Creating new socket after closing an old one causes connection refused

问题描述

我是新到Android编程，我试图从端口标准的Java程序到Android。这个Java应用程序包含插槽。当我移植程序我得到一个连接被拒绝，如果我preSS按钮太快。我做了一个简单的程序进行测试。

I'm new to android programming and I'm trying to port a program from standard java to android. This java application contains sockets. When I ported the program I get a connection refused if I press a button too fast. I made a simple program for testing.

Thread thread = new Thread(new Runnable() {
    @Override
    public void run() {
        try {
            Socket mySocket = new Socket();
            InetSocketAddress address = new InetSocketAddress("10.94.35.24", 5000);
            mySocket.connect(address, 5000);
            mySocket.shutdownOutput();
            mySocket.shutdownInput();
            mySocket.close();
            Log.w("Socket", "Socket closed");
            Socket mySocket2 = new Socket();
            mySocket2.connect(address, 5000);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
});
thread.start();

我有一台服务器和这个IP和端口运行，我的程序正常工作在我的计算机上的Java应用程序。但在Android的程序获取尝试连接到mySocket2时以下异常

I have a server up and running on this IP and port and my program works fine on a java application on my computer. But on android the program gets the following exception when trying to connect to mySocket2

java.net.ConnectException：无法连接到/10.94.35.24（端口
  5000）后，5000毫秒：isConnected失败：ECONNREFUSED（连接
  拒绝）

java.net.ConnectException: failed to connect to /10.94.35.24 (port 5000) after 5000ms: isConnected failed: ECONNREFUSED (Connection refused)

我的猜测是，这事做与Android操作系统的限制，但我希望不会。有谁知道，如果我做错事，或可以确认插座，Android的这些限制？

My guess is that this has something to do with a limitation in the android OS but I hope not. Does anyone know if I'm doing something wrong or can confirm that sockets have these limitations in Android?

推荐答案

的公共类的ConnectException
扩展SocketException

public class ConnectException extends SocketException

说：，同时试图将套接字连接到远程地址和端口时发生了错误的信号。通常情况下，连接被远程拒绝（例如，没有任何进程正在监听的远程地址/端口）。的

连接被拒绝错误意味着在服务器计算机上的插座堆栈收到连接请求，并故意拒绝接受。出现这种情况的两个可能的原因：

"Connection Refused" error means the socket stack on the server machine received your connection request and intentionally refused to accept it. That happens for one of two possible reasons:

1）是您试图连接的端口上没有运行监听套接字。

1) There is no listening socket running on the port you are trying to connect to.

2）有一个监听套接字，但它挂起连接的积压是满的，所以没有空间来排队你在那一刻的请求。

2) There is a listening socket, but its backlog of pending connections is full, so there is no room to queue your request at that moment.

要区分这两种，尝试在每次尝试之间的延迟重新连接几次。如果你得到同样的错误持续，那么＃1可能是罪魁祸首。确保端口号是正确的。如果＃2是罪魁祸首，您重新连接了最终成功的机会。

To differentiate between the two, try reconnecting a few times with a delay in between each attempt. If you get the same error consistently, then #1 is likely the culprit. Make sure the port number is correct. If #2 is the culprit, your reconnect has a chance of succeeding eventually.

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