我的数据库是这样的

我的名字是anand，我创建了一个应用程序，我使用了底部导航。使用了3个片段，其中一个用于显示课程（pdf文件）。我只想向特定用户显示特定课程，这意味着当用户注册时，他们会强制选择课程。根据他们选择的课程名称，他们只能得到特定的pdf文件。根据我目前的代码，它显示了一切，我只需要显示根据课程名称和用户的课程。我的代码如下所述
在此处输入代码

public class CourseFragment extends android.support.v4.app.Fragment {
//the listview
ListView listView;

//database reference to get uploads data
DatabaseReference mDatabaseReference;

//list to store uploads data
List<Upload> uploadList;

public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.activity_course_fragment, null);

    uploadList = new ArrayList<>();
    listView = (ListView) v. findViewById(R.id.listView);
    final  WebView webView= (WebView) v. findViewById(R.id.webview);

       //adding a clicklistener on listview
       listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
           @Override
           public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
               //getting the upload
               Upload upload = uploadList.get(i);

               //Opening the upload file in browser using the upload url
               Intent intent = new Intent(Intent.ACTION_VIEW);
               intent.setData(Uri.parse(upload.getUrl()));
               startActivity(intent);

           }
       });

    //getting the database reference
    mDatabaseReference = FirebaseDatabase.getInstance().getReference(Constants.DATABASE_PATH_UPLOADS);

    //retrieving upload data from firebase database
    mDatabaseReference.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            for (DataSnapshot postSnapshot : dataSnapshot.getChildren()) {
                Upload upload = postSnapshot.getValue(Upload.class);
                uploadList.add(upload);
            }

            String[] uploads = new String[uploadList.size()];

            for (int i = 0; i < uploads.length; i++) {
                uploads[i] = uploadList.get(i).getName();
            }

            //displaying it to list
            ArrayAdapter<String> adapter = new ArrayAdapter<String>(getContext(), android.R.layout.simple_list_item_1, uploads);
            listView.setAdapter(adapter);
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });
    return v;
}