How to extend from AsyncTask as a generic base class?

Question

There are three different implementations of an AsyncTask:

public class DownloadTask extends AsyncTask<String, Integer, Boolean>
public class JsonParserTask extends AsyncTask<Object, Void, Boolean>
public class PostCommentTask extends AsyncTask<String, Void, HttpRequestResult>

I would like them to extend a BaseAsyncTask which I can use for dependency injection then. The class signatur of AsyncTask looks like this:

public abstract class AsyncTask<Params, Progress, Result>

How can I extend AsyncTask while maintaining the different parameters?

                               | DownloadTask
AsyncTask <-- BaseAsyncTask <--| JsonParserTask
                               | PostCommentTask

Answer 1

Try:

abstract class BaseAsyncTask<Params, Progress, Result> 
                  extends AsyncTask<Params, Progress, Result>