Android app crashes due to NetworkOnMainThreadException

Question

I want to develop an app that allows me to upload data from form of an android app as a text file in server here is the mainactivity class

    package com.example.incrediblemachine.sendtest;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends Activity {

    EditText msgTextField;
    Button sendButton;

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

        //make message text field object
        msgTextField = (EditText) findViewById(R.id.msgTextField);
        //make button object
        sendButton = (Button) findViewById(R.id.sendButton);
    }

    public void send(View v)
    {
        //get message from message box
        String  msg = msgTextField.getText().toString();

        //check whether the msg empty or not
        if(msg.length()>0) {
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("http://ramsproject.16mb.com/sendorder.php");

            try {
                List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
                nameValuePairs.add(new BasicNameValuePair("id", "01"));
                nameValuePairs.add(new BasicNameValuePair("message", msg));
                httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                httpclient.execute(httppost);
                msgTextField.setText(""); //reset the message text field
                Toast.makeText(getBaseContext(),"Sent",Toast.LENGTH_SHORT).show();
            }catch (IllegalStateException e)
            {
                e.printStackTrace();
            }
            catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        } else {
            //display message if text field is empty
            Toast.makeText(getBaseContext(),"All fields are required",Toast.LENGTH_SHORT).show();
        }
    }

}

It comes up with an exception at line 53 httpclient.execute(httppost);

the exception says android.app.NetworkOnMainThreadException How do i solve this

Answer 1

Just use a thread.

Thread thread = new Thread(new Runnable(){
    @Override
    public void run() {
        try {
            //Your code goes here
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
});

thread.start(); 

call the httpClient in this thread.