HttpURLConnection请求图片

效果图：

页面代码：

public class HttpJpgActivity extends Activity {
    private ImageView view;
    private Handler handler;
    private File file = new File(Environment.getExternalStorageDirectory(), "baidu.jpg");

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

        view = (ImageView) findViewById(R.id.iv_city);
        new Thread(new ImageThread()).start();

        handler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                try {
                    FileInputStream fileInputStream = new FileInputStream(file);
                    Bitmap bitmap = BitmapFactory.decodeStream(fileInputStream);
                    view.setImageBitmap(bitmap);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }
            }
        };
    }


    public class ImageThread implements Runnable {

        @Override
        public void run() {
            try {
                URL url = new URL("http://www.baidu.com/img/bdlogo.png");
                HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
                urlConnection.setRequestMethod("GET");
                urlConnection.setConnectTimeout(3000);
                urlConnection.setReadTimeout(3000);
                urlConnection.connect();
                FileOutputStream fileOutputStream = new FileOutputStream(file);

                if (urlConnection.getResponseCode() == 200) {
                    InputStream inputStream = urlConnection.getInputStream();
                    byte[] bytes = new byte[1024];
                    int len;
                    while ((len = inputStream.read(bytes)) != -1) {
                        fileOutputStream.write(bytes, 0, len);
                    }
                    //将缓冲刷入文件
                    fileOutputStream.flush();
                    handler.sendEmptyMessage(0x001);
                }
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

权限：

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