as任务下载并将Jpg设置为imageView

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

private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
    ImageView imageView;

    public DownloadImageTask(ImageView imageView) {
        this.imageView = imageView;
    }

    protected Bitmap doInBackground(String... urls) {
        String imageUrl = urls[0];
        Bitmap bitmap = null;
        try {
            InputStream in = new java.net.URL(imageUrl).openStream();
            bitmap = BitmapFactory.decodeStream(in);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return bitmap;
    }

    protected void onPostExecute(Bitmap result) {
        imageView.setImageBitmap(result);
    }
}

ImageView imageView = findViewById(R.id.imageView);
String imageUrl = "http://example.com/image.jpg";
new DownloadImageTask(imageView).execute(imageUrl);