Android使用线程获取网络图片的方法

package com.zdcrobot.handlermessage;
 
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
 
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
 
public class MainActivity extends AppCompatActivity {
  private Button button;
  private ImageView imageView;
  private String imagPath = "http://pica.nipic.com/2007-11-09/200711912453162_2.jpg";
  private final int IS_FINISH = 1;
  private Handler handler = new Handler(){
    @Override
    public void handleMessage(Message msg) {
      Bitmap bitmap = (Bitmap)msg.obj;
      imageView.setImageBitmap(bitmap);
    }
  };
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    button = (Button)findViewById(R.id.button1);
    imageView = (ImageView)findViewById(R.id.image1);
    button.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        new Thread(new MyClass()).start();
      }
    });
  }
 
  public class MyClass implements Runnable{
 
    @Override
    public void run() {
      Bitmap bitmap = null;
      try {
        URL url = new URL(imagPath);
        HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
        httpURLConnection.setDoInput(true);
        httpURLConnection.connect();
        InputStream inputStream = httpURLConnection.getInputStream();
        bitmap = BitmapFactory.decodeStream(inputStream);
      } catch (MalformedURLException e) {
        e.printStackTrace();
      } catch (IOException e) {
        e.printStackTrace();
      }
      Message message = Message.obtain();
      message.obj = bitmap;
      message.what = IS_FINISH;
      handler.sendMessage(message);
    }
  }
}