慢 Android 使用线程的 Modbus 连接

Question

app功能是连接PLC。我在 PLC 上使用 Modbus 服务器，在 Android 应用程序中使用 EasyModbus 客户端。如果应用程序第一次连接失败，大约需要 2-3 分钟才能再次尝试连接。它通常在主线程上运行，但是当我将它移动到单独的线程时，问题就出现了。

我尝试更改连接超时，但没有结果。

public void connect() {

Thread thread = new Thread(new Runnable() {

            @Override
            public void run() {
                while(!connected) {
                    ModbusClient modbusClient = new ModbusClient("192.168.0.1", 502);
                    modbusClient.setConnectionTimeout(30);

                    try {
                        Log.e(TAG, "Try connecting to port: " + 502;
                        modbusClient.Connect();
                        connected = true;
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        });

        thread.start();
}

日志：

Try connecting to port: 502
W/System: A resource failed to call close. 
W/System.err: java.net.ConnectException: failed to connect to /192.168.21.136 (port 1201) from /:: (port 46369): connect failed: ETIMEDOUT (Connection timed out)
W/System.err:     at libcore.io.IoBridge.connect(IoBridge.java:142)
W/System.err:     at java.net.PlainSocketImpl.socketConnect(PlainSocketImpl.java:142)
W/System.err:     at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:390)
W/System.err:     at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:230)
W/System.err:     at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:212)
W/System.err:     at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:436)
        at java.net.Socket.connect(Socket.java:621)
W/System.err:     at java.net.Socket.connect(Socket.java:570)
W/System.err:     at java.net.Socket.<init>(Socket.java:450)
W/System.err:     at java.net.Socket.<init>(Socket.java:218)
W/System.err:     at de.re.easymodbus.modbusclient.ModbusClient.Connect(ModbusClient.java:88)
W/System.err:     at com.example.roseoilproduction.MainActivity.run(MainActivity.java:101)
W/System.err:     at java.lang.Thread.run(Thread.java:923)
W/System.err: Caused by: android.system.ErrnoException: connect failed: ETIMEDOUT (Connection timed out)
W/System.err:     at libcore.io.Linux.connect(Native Method)
W/System.err:     at libcore.io.ForwardingOs.connect(ForwardingOs.java:94)
        at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:138)
W/System.err:     at libcore.io.ForwardingOs.connect(ForwardingOs.java:94)
        at libcore.io.IoBridge.connectErrno(IoBridge.java:156)
        at libcore.io.IoBridge.connect(IoBridge.java:134)
        ... 12 more

Answer 1

记住线程的工作原理后，我添加了计时器以每 x 秒执行一次线程：

Timer timer = new Timer();
        timer.schedule(new TimerTask()
        {
            @Override
            public void run()
            {
                connect();
            }
        }, 0, 1000);

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