Send Socket From Android To A Python Server

Question

Clarification:

The two device connect to the same network local
The address IP is the correct
Already try using different ports
Android app permissions were successfully added
The image shows that the app android running on machine virtual also were tested on device the real

intention: I intend that my phone can send data to the computer through sockets

Server(Python):

import socket  

s = socket.socket()   
s.bind(("192.168.1.94", 60))  
s.listen(1)  #clients permitted connect
print "server run"

sc, addr = s.accept()  

while True:  
      recibido = sc.recv(1024)  
      if recibido == "quit":  
         break        
      print "received:", recibido  
      sc.send(recibido)  

print "bye"  

sc.close()  
s.close()

Java(Client):

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button button = findViewById(R.id.idbtn);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                Socket socket = new Socket("192.168.1.94",60);
                DataOutputStream DOS = new DataOutputStream(socket.getOutputStream());
                DOS.writeUTF("HELLO_WORLD");
                socket.close();
            }
        });
    }

Message of error:

2019-12-27 17:30:03.362 9255-9281/com.example.milchycompany.myapplication E/eglCodecCommon: glUtilsParamSize: unknow param 0x00008cdf
2019-12-27 17:30:03.362 9255-9281/com.example.milchycompany.myapplication E/eglCodecCommon: glUtilsParamSize: unknow param 0x00008824
2019-12-27 17:30:41.054 9255-9255/com.example.milchycompany.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.milchycompany.myapplication, PID: 9255
    android.os.NetworkOnMainThreadException
        at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1303)
        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:333)
        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:196)
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:178)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:356)
        at java.net.Socket.connect(Socket.java:586)
        at java.net.Socket.connect(Socket.java:535)
        at java.net.Socket.<init>(Socket.java:427)
        at java.net.Socket.<init>(Socket.java:210)
        at com.example.milchycompany.myapplication.MainActivity$1.onClick(MainActivity.java:32)
        at android.view.View.performClick(View.java:5610)
        at android.view.View$PerformClick.run(View.java:22265)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6077)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)

Look at the error: NetworkOnMainThreadException – jeprubio Dec 27 '19 at 23:35 — jeprubio, Dec 27 '19 at 23:35
I only send the data but I do not receive data – Diego Dec 27 '19 at 23:37 — Diego, Dec 27 '19 at 23:37

FLASHCODER · Accepted Answer · 2019-12-28T00:09:24.003

This happens because you are doing a I/O network operation on the main thread. You should always run network operations on a thread or as an asynchronous task.

See the examples below.

Thread:

Thread thread = new Thread(new Runnable() {

    @Override
    public void run() {
        try  {
            Socket socket = new Socket("192.168.1.94",60);
            DataOutputStream DOS = new 
            DataOutputStream(socket.getOutputStream());
            DOS.writeUTF("HELLO_WORLD");
            socket.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
});

thread.start();

AsyncTask

class ConnAsyncTask extends AsyncTask<Void, Integer, String> {
    protected String doInBackground(Void... arg0) {

        try {
            Socket socket = new Socket("192.168.1.94",60);
            DataOutputStream DOS = new 
            DataOutputStream(socket.getOutputStream());
            DOS.writeUTF("HELLO_WORLD");
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "";
    }
}

Usage:

new ConnAsyncTask().execute();

And never forget of add this permission to AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET"/>

Send Socket From Android To A Python Server

1 Answers1