Implement full exit program method in android (exit all activity)

This is a problem that many, many people encounter. I have tried many methods, but none of them work well.
Such as:

System.exit(0);

I can't.
What else jumps to the first activity, while clearing all activity at the top of the stack, and finally finish(); Still no. I don't know why.
Here's one of my own that works really well.
Principle: Each activity registers a broadcast receiver to receive broadcasts that turn off activity. When the program needs to exit, send a radio to turn off activity, so that all activity will receive, and then all activity will be finish.

package com.example.exitsystem;
import android.app.Activity;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.os.Bundle;
/**

 *  all activity You inherit this class, and you register a broadcast, 

 *  You can send a broadcast when you need to exit the system completely, 

 * action for com.example.exitsystem.system_exit (Custom), 

 *  This allows you to exit all at any time activity the 

 * @author LinZhiquan

 *

 */

public class SuperActivity extends Activity {

 /**  radio action */

 public static final String SYSTEM_EXIT = "com.example.exitsystem.system_exit";

 /**  The receiver  */

 private MyReceiver receiver;

 

 @Override

 protected void onCreate(Bundle savedInstanceState) {

  super.onCreate(savedInstanceState);

  

  // Register the broadcast to exit the program 

  IntentFilter filter = new IntentFilter();

  filter.addAction(SYSTEM_EXIT);

  receiver = new MyReceiver();

  this.registerReceiver(receiver, filter);

 }

 

 @Override

 protected void onDestroy() {

  // Remember to cancel your broadcast registration 

  this.unregisterReceiver(receiver);

  super.onDestroy();

 }

 

 private class MyReceiver extends BroadcastReceiver {

  @Override

  public void onReceive(Context context, Intent intent) {

   finish();

  }

 }

}

package com.example.exitsystem;
import android.os.Bundle;
/**

 *  ordinary activity .   inheritance SuperActivity

 * @author LinZhiquan

 *

 */

public class MainActivity extends SuperActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

}

Send a broadcast when you need to exit the program.

        Intent intent = new Intent();

        intent.setAction(SuperActivity.SYSTEM_EXIT);

        sendBroadcast(intent);