我的代码：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ArrayList<BookData> arrayList = new ArrayList<>();
    recyclerAdapter = new RecyclerAdapter(this,arrayList);
    recyclerview = (RecyclerView)findViewById(R.id.recyclerView);
                   recyclerview.setLayoutManager(new 
    LinearLayoutManager(this));
    recyclerview.setAdapter(recyclerAdapter);
    android.app.LoaderManager loaderManager = getLoaderManager();
    Log.i(TAG, "Now calling initLoader");
    loaderManager.initLoader(BOOK_LOADER_ID, null, this);
    DividerItemDecoration dividerItemDecoration = new 
    DividerItemDecoration(this,DividerItemDecoration.VERTICAL);
    recyclerview.addItemDecoration(dividerItemDecoration);
}
@NonNull
@Override
public Loader<List<BookData>> onCreateLoader(int id, @Nullable Bundle args) {
    Log.i(TAG,"Problem with onCreateloader");
    return new BookLoader(MainActivity.this,GOOGLEBOOKURL);
}
@Override
public void onLoadFinished(@NonNull Loader<List<BookData>> loader, List<BookData> data) {
    recyclerAdapter.clear();
    if (data != null && !data.isEmpty()) {
        recyclerAdapter.addAll(data);
    }
}
@Override
public void onLoaderReset(@NonNull Loader<List<BookData>> loader) {
    recyclerAdapter.clear();
    Log.i(TAG, "Now loader is resetting");
}

显示类定义的屏幕截图
错误：

Process: com.example.booklistapp, PID: 8575
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.booklistapp/com.example.booklistapp.MainActivity}: java.lang.ClassCastException: com.example.booklistapp.MainActivity cannot be cast to android.app.LoaderManager$LoaderCallbacks
                    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665)
                    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
                    at android.app.ActivityThread.-wrap12(ActivityThread.java)
                    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
                    at android.os.Handler.dispatchMessage(Handler.java:102)

我试图解决我在androidx中遇到的错误，但是没有 initloader() 以及 getManager() 调用加载程序。如何通过initloader调用加载程序？

android.app.LoaderManager loaderManager = getLoaderManager();
            Log.i(TAG, "Now calling initLoader");
            loaderManager.initLoader(BOOK_LOADER_ID, null, this);

我在androidx加载程序中使用android应用程序加载程序，因为没有 initLoader() 以及 getManager() 在androidx。
谢谢您。