Activity在回调函数执行前被finish会引起崩溃吗？

假设有如下情景，activity实现了接口interface A，override了操作函数function( )（是对activity里面的一些变量进行处理）,activity里面开了两个线程（Thread1，Thread2）进行网络访问，Thread2中网络访问有响应后执行了回调函数function，而Thread1网络访问有响应了之后执行的是把activity finish掉（回调也好，广播也好，反正就是把activity finish掉），那么恰好又是Thread1比Thread2快执行完毕，那么Thread2到了回调函数那里会不会有空指针之类的错误呢？

package com.example.ab;

import java.util.ArrayList;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends ActionBarActivity {

private ArrayList<Integer> list;
private int i;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    list = new ArrayList<Integer>();
    new Thread(new Runnable() {

        @Override
        public void run() {
            // TODO Auto-generated method stub
            while (i <= 10) {
                i++;
                list.add(i);
                Log.d("TAG", "aa = " + i);
                try {
                    Thread.sleep(500);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }).start();
    new Thread(new Runnable() {

        @Override
        public void run() {
            // TODO Auto-generated method stub
            try {
                Thread.sleep(3000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            Log.d("TAG", "finish");
            finish();


        }
    }).start();

}

@Override
protected void onDestroy() {
    // TODO Auto-generated method stub
    super.onDestroy();
    Log.d("TAG", "onDestroy");
}

}

日志：
01-02 09:08:22.649: D/TAG(4925): aa = 1
01-02 09:08:23.149: D/TAG(4925): aa = 2
01-02 09:08:23.659: D/TAG(4925): aa = 3
01-02 09:08:24.159: D/TAG(4925): aa = 4
01-02 09:08:24.659: D/TAG(4925): aa = 5
01-02 09:08:25.159: D/TAG(4925): aa = 6
01-02 09:08:25.659: D/TAG(4925): aa = 7
01-02 09:08:25.669: D/TAG(4925): finish
01-02 09:08:25.679: D/TAG(4925): onDestroy
01-02 09:08:26.159: D/TAG(4925): aa = 8
01-02 09:08:26.659: D/TAG(4925): aa = 9
01-02 09:08:27.159: D/TAG(4925): aa = 10
01-02 09:08:27.659: D/TAG(4925): aa = 11