致命异常:异步任务#2

Question

我有3个按钮和一个Gallery。在我的Gallery中，我有三个ImageAdapters，每个按钮都有一个，我正在设置一个缩略图URL，该URL必须提取并加载到这些ImageAdapters中，我正在使用AsyncTask。

代码：

 class AddImageTask extends AsyncTask<Void, Void, Void> {
    @Override
    protected Void doInBackground(Void... unused) {
         try {
         for (String url : PhotoURLS) {
         String filename = url.substring(url.lastIndexOf("/") +
         1,url.length());
         filename = "" + filename;
         String thumburl = url.substring(0, url.lastIndexOf("/") + 1);
         imageAdapter.addItem(LoadThumbnailFromURL(thumburl+ filename));
         publishProgress();
         }
         for (String url : AudioThumbURLS) {
         String filename = url.substring(url.lastIndexOf("/") +
         1,url.length());
         filename = "" + filename;
         String thumburl = url.substring(0, url.lastIndexOf("/") + 1);
         imageAdapter1.addItem(LoadThumbnailFromURL(thumburl+ filename));
         publishProgress();
         }
         for (String url : VideoThumbURLS) {
         String filename = url.substring(url.lastIndexOf("/") +
         1,url.length());
         filename = "" + filename;
         String thumburl = url.substring(0, url.lastIndexOf("/") + 1);
         imageAdapter2.addItem(LoadThumbnailFromURL(thumburl+ filename));
         publishProgress();
         }
         } catch (Exception ae) {
         ae.printStackTrace();
         Toast.makeText(getApplicationContext(),"Error found in the application",
         Toast.LENGTH_LONG).show();
         }
        return (null);
    }
    @Override
    protected void onProgressUpdate(Void... unused) {
        imageAdapter.notifyDataSetChanged();
        imageAdapter1.notifyDataSetChanged();
        imageAdapter2.notifyDataSetChanged();
    }
    @Override
    protected void onPostExecute(Void unused) {
    }
}

我的LoadThumbnailFromURL方法是：

   private Drawable LoadThumbnailFromURL(String url) {
    try {
        URLConnection connection = new URL(url).openConnection();
        String contentType = connection.getHeaderField("Content-Type");
        boolean isImage = contentType.startsWith("");
        if (isImage) {
            HttpGet httpRequest = new HttpGet(url);
            HttpClient httpclient = new DefaultHttpClient();
            HttpResponse response = (HttpResponse) httpclient
                    .execute(httpRequest);
            HttpEntity entity = response.getEntity();
            BufferedHttpEntity bufferedHttpEntity = new BufferedHttpEntity(
                    entity);
            InputStream is = bufferedHttpEntity.getContent();
            Drawable d = Drawable.createFromStream(is, "src name");
            return d;
        } else {
            Bitmap b = BitmapFactory.decodeResource(getResources(),
                    R.drawable.icon);
            Drawable d = new BitmapDrawable(b);
            return d;
        }
    } catch (Exception e) {
        Toast.makeText(getApplicationContext(), "error", Toast.LENGTH_LONG)
                .show();
        Log.e(e.getClass().getName(), e.getMessage(), e);
    }
    return null;
}

应用程序启动良好，但过了一段时间后抛出错误：

01-21 15:16:23.750:E/AndroidRuntime（8292）：致命异常：AsyncTask#201-21 15:16:23.750:E/AndroidRuntime（8292）：在java.util.concurrent.FFutureTask$Sync.innerSetException（FutureTask.java:273）01-21 15:16:23.750:E/AndroidRuntime（8292）：在java.util.concurrent.FFutureTask.setException（FutureTask.java:124）01-21 15:16:23.750:E/AndroidRuntime（8292）：在java.util.concurrent.FFutureTask$Sync.innerRun（FutureTask.java:307）01-21 15:16:23.750:E/AndroidRuntime（8292）：在java.util.concurrent.FFutureTask.run（FutureTask.java:137）01-21 15:16:23.750:E/AndroidRuntime（8292）：在java.util.concurrent.FFutureTask$Sync.innerRun（FutureTask.java:305）

可能的原因是什么？我该如何解决？

Answer 1

您是否有可能捕获一个异常，但在捕获｛｝中却捕获了另一个异常？由于它在另一个（非UI）线程上，所以不要试图使用Toast来通知自己错误。