小编use*_*240的帖子

我定义了以下类:

class Operation<S>
class GetReservationOperation extends Operation<Reservation>

现在我想要一个这样的课程:

OperationExecutor<T extends Operation<S>> extends AsyncTask<T,Void,S>{
    @Override
    protected S doInBackground(T... params) {
       return null;
    }
}

但这不会编译:

OperationExecutor<GetReservationOperation> executor = new ....

为什么Java不允许这样做？

过了一段时间我想出了以下解决方案:

OperationExecutor<T extends Operation<S>,S> extends AsyncTask<T,Void,S>{
    @Override
    protected S doInBackground(T... params) {
       return null;
    }
}

但这迫使我写下以下内容:

OperationExecutor<GetReservationOperation,Reservation> executor = new .... 

这看起来很奇怪.有没有办法让它看起来更好？

编辑 这个工作

OperationExecutor<S> extends AsyncTask<Operation<S>,Void,S>{
    @Override
    protected S doInBackground(Operation<S>... params) {
       return null;
    }
}

OperationExecutor<Reservation> executor = new ....
executor.execute(getReservationOperation);