android - 连接时套接字超时

Question

我正在尝试在 Android 上实现一个 tcp 客户端应用程序。当我尝试连接到我的 C++ 服务器时，套接字在尝试连接到服务器时超时。

我的代码:

new Thread(new ClientThread()).start();
try
{
  PrintWriter out = new PrintWriter(new BufferedWriter(
    new OutputStreamWriter(socket.getOutputStream())), true);
  out.println("Test message.");
}
catch (Exception e)
{
  // ERROR1
  e.printStackTrace();
}

...

class ClientThread implements Runnable
{
  @Override
  public void run()
  {
    try
    {
      InetAddress serverAddr = InetAddress.getByName("192.168.1.116");
      socket = new Socket(serverAddr, 9000);
    }
    catch (Exception e)
    {
      // ERROR2
      e.printStackTrace();
    }
  }
}

首先，发生ERROR1(套接字为空)，然后发生ERROR2(连接超时)。服务器工作正常，我已经用不同的客户端进行了测试。我有“使用许可”，所以这应该不是问题。

编辑:在 ERROR2 处堆栈:

05-17 02:26:50.789: W/System.err(26625): java.net.ConnectException: failed to connect to /192.168.1.116 (port 9000): connect failed: ETIMEDOUT (Connection timed out)
05-17 02:26:50.789: W/System.err(26625):    at libcore.io.IoBridge.connect(IoBridge.java:114)
05-17 02:26:50.789: W/System.err(26625):    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
05-17 02:26:50.789: W/System.err(26625):    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
05-17 02:26:50.789: W/System.err(26625):    at java.net.Socket.startupSocket(Socket.java:566)
05-17 02:26:50.789: W/System.err(26625):    at java.net.Socket.<init>(Socket.java:225)
05-17 02:26:50.789: W/System.err(26625):    at cz.gclient.gardenclient.MainActivity$ClientThread.run(MainActivity.java:153)
05-17 02:26:50.789: W/System.err(26625):    at java.lang.Thread.run(Thread.java:841)
05-17 02:26:50.789: W/System.err(26625): Caused by: libcore.io.ErrnoException: connect failed: ETIMEDOUT (Connection timed out)
05-17 02:26:50.789: W/System.err(26625):    at libcore.io.Posix.connect(Native Method)
05-17 02:26:50.789: W/System.err(26625):    at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:85)
05-17 02:26:50.789: W/System.err(26625):    at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
05-17 02:26:50.789: W/System.err(26625):    at libcore.io.IoBridge.connect(IoBridge.java:112)
05-17 02:26:50.789: W/System.err(26625):    ... 6 more

Answer 1

“连接超时”是网络连接问题。例如，可能存在防火墙。这不是编程问题，您无法用代码解决它。