java从URL获取位图

Question

我正在尝试从URL获取位图图像
（示例：https://cdn.bulbagarden.net/upload/9/9a/Spr_7s_001.png）

但是connection.connect()行似乎有一个问题，我无法理解
我已允许在应用程序中访问internet

public static Bitmap getBitmapFromURL(String src) {
    HttpURLConnection connection = null;
    InputStream inputStream = null;
    try {
        URL url = new URL(src);
        connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("GET");
        connection.setDoInput(true);
        connection.connect();
    }
    return BitmapFactory.decodeStream(inputStream);
}  

Answer 1

你可以用glide做一个简短的解决方案

    implementation "com.github.bumptech.glide:glide:4.11.0"
    annotationProcessor "com.github.bumptech.glide:compiler:4.11.0"

 try {
                        Bitmap bitmap = Glide
                                .with(context)
                                .asBitmap()
                                .load(imageUrl)
                                .submit()
                                .get();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }

Answer 2

一般来说，网络连接应该在一个单独的线程中完成。你可以用AsyncTask来做这个。例如，这是有效的：

ImageView imageView;

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

    imageView = (ImageView) findViewById(R.id.imageView);
    new LoadImage().execute("https://cdn.bulbagarden.net/upload/9/9a/Spr_7s_001.png");
}

private class LoadImage extends AsyncTask<String, Void, Bitmap>{
       @Override
       protected Bitmap doInBackground(String... strings) {
           Bitmap bitmap = null;
           try {
               InputStream inputStream = new URL(strings[0]).openStream();
               bitmap = BitmapFactory.decodeStream(inputStream);
           } catch (IOException e) {
               e.printStackTrace();
           }
           return bitmap;
       }

       @Override
       protected void onPostExecute(Bitmap bitmap) {
           imageView.setImageBitmap(bitmap);
       }
   }