多个异步任务挂起应用程序

In my android App, I use multiple AsyncTask using THREAD_POOL_EXECUTOR which makes the tasks run in parallel. Sometime the app hangs. Below is the code I use.

在我的android应用程序中，我使用THREAD_POOL_EXECUTOR使用多个AsyncTask，使任务并行运行。有时应用程序挂起。下面是我使用的代码。

Could you please let me know how to fine tune so as to avoid any hanging issue ?
你能告诉我如何调好调子，以免有任何悬而未决的问题吗?

How to find the point in which app is hanging ?

如何找到应用的挂点?

new fetchInitialCoinsParallel().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, url);

prefCoinList = getPrefCoin();
if(prefCoinList.size()>0){
    for(int i=0;i<prefCoinList.size();i++){
        new fetchAltCoinsParallel().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, url);
    }
}

public class fetchAltCoinsParallel extends AsyncTask<String, String, String> {
@Override
protected void onPreExecute() {
}

protected String doInBackground(String... params) {
    try {
        InputStream is = getDataFromURL(params[0]);
        if(is!=null){
            BufferedReader br = new BufferedReader(new InputStreamReader(is));
            synchronized(this){
                brList.add(br);
            }

        }else{
            prefCoinNotLoadedTimeOutCount=prefCoinNotLoadedTimeOutCount+1;
        }


        if(brList.size()==prefCoinList.size()-prefCoinNotLoadedTimeOutCount){
            try {
                loadAltCoins(getAltCoinDataParallel());
            } catch (IOException e) {
                e.printStackTrace();
            }

            maingame.dataReady=true;
        }

    } catch (IOException e) {
        e.printStackTrace();
    } 
    return null;
}

protected void onPostExecute(String params) {
}
protected void onProgressUpdate(String... progress) {
}

}

Thread details

线程的细节

2 个解决方案

#1

Instead of using Async Tasks, i recommend using RXJAVA for this purpose.

我建议使用RXJAVA来实现这个目的，而不是使用异步任务。

Here is the disadvantage given for Async Task: https://*.com/a/9654445/9100553

异步任务的缺点是:https://*.com/a/9654445/9100553

Using RxJava will solve this problem, here is an perfect blog which can solve your problem of Multi Threading using RxJava.

使用RxJava将解决这个问题，这里有一个完美的博客，可以使用RxJava解决多线程问题。

http://www.nurkiewicz.com/2017/09/idiomatic-concurrency-flatmap-vs.html

(Read the second half) Both flatmap and parallel operators would be useful in your case.

(读下半部分)平面映射和并行运算符在您的例子中都是有用的。

#2

Check the AsyncTaskLoader concept. This feature is supported by Android community introduced in API level 11 along with Honeycomb features.

检查AsyncTaskLoader概念。该特性由API级11中引入的Android社区支持，并带有蜂巢特性。

AsyncTaskLoader solved the lot of limitations & workaround solutions of the AsyncTask.java

AsyncTaskLoader解决了AsyncTask.java的许多限制和解决方案

Official : https://developer.android.com/reference/android/content/AsyncTaskLoader.html

官方:https://developer.android.com/reference/android/content/AsyncTaskLoader.html

Good Sample: https://medium.com/google-developers/making-loading-data-on-android-lifecycle-aware-897e12760832

好示例:https://medium.com/google developers/making -加载数据——- android -生命周期-了解- 897 e12760832

public class JsonAsyncTaskLoader extends AsyncTaskLoader<List<String>> {
    // You probably have something more complicated
    // than just a String. Roll with me
    private List<String> mData;

    public JsonAsyncTaskLoader(Context context) {
        super(context);
    }

    @Override
    protected void onStartLoading() {
        if (mData != null) {
            // Use cached data
            deliverResult(mData);
        } else {
            // We have no data, so kick off loading it
            forceLoad();
        }
    }

    @Override
    public List<String> loadInBackground() {
        // This is on a background thread
        // Good to know: the Context returned by getContext()
        // is the application context
        File jsonFile = new File(
                getContext().getFilesDir(), "downloaded.json");
        List<String> data = new ArrayList<>();
        // Parse the JSON using the library of your choice
        // Check isLoadInBackgroundCanceled() to cancel out early
        return data;
    }

    @Override
    public void deliverResult(List<String> data) {
        // We’ll save the data for later retrieval
        mData = data;
        // We can do any pre-processing we want here
        // Just remember this is on the UI thread so nothing lengthy!
        super.deliverResult(data);
    }
}

#1