Modbus protocol escapes the thread (Android,Jamod)

Question

I'm trying to connect to PLC using ModBus protocol. I'm calling ModBus connect method from thread and I'm getting exception that I'm running communications on the main thread... I wonder where it escapes...

Exception:



    08-02 10:48:44.461: W/System.err(4395): android.os.NetworkOnMainThreadException
    08-02 10:48:44.471: W/System.err(4395):     at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
    08-02 10:48:44.471: W/System.err(4395):     at

Code:




    package com.kikudjiro.android.echo;

    import net.wimpi.modbus.facade.ModbusTCPMaster;
    import android.app.Activity;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;

    public class settings extends Activity implements Runnable {

        Button connect_b, disconnect_b;
        Thread comm = new Thread(this);

        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.settings);
            addListenerOnButton();
        }

        public void addListenerOnButton() {

            connect_b = (Button) findViewById(R.id.button1);
            disconnect_b = (Button) findViewById(R.id.button2);
            connect_b.setOnClickListener(new OnClickListener() {
                public void onClick(View arg0) {
                    comm.run();
                }

            });

            disconnect_b.setOnClickListener(new OnClickListener() {

                public void onClick(View arg0) {
                    comm.interrupt();
                }

            });
        }

        // @Override
        public void run() {

            try {
                ModbusTCPMaster MB = new ModbusTCPMaster("192.168.107.29", 502);
                //while (!comm.interrupted()) {
                    Log.i("!!!!!!!", "try!");
                    MB.connect();
                    MB.writeCoil(1, 1, true);
                    MB.disconnect();
                //}
            }

            catch (Exception ex) {
                ex.printStackTrace();
                Log.i("hhh", "exceptionas!!!");
            } finally {
                Log.i("!!!!!!!", "finally!");
            }

        }

    }

score 0 · Accepted Answer · answered Aug 02 '12 at 08:48

On button click, you call comm.run() which just executes the run() method directly in the context of the UI thread. This is a common error, you should never call run() directly on a Thread instance. Use comm.start() to execute the Modbus code in the context of your worker thread.

Here is the Javadoc

Modbus protocol escapes the thread (Android,Jamod)

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