Kann aus der Firebase Real-Time-Datenbank mit einem nicht angegebenen Index nicht entfernt werden

Question

Ich habe diese Nachricht erhalten, wenn ich auf das Löschen-Symbol in meiner Anwendung klicke. Ich verstehe nicht, was passiert ist, weil es funktioniert hat. Bitte hilf mir.

W/PersistentConnection: pc_0 - Using an unspecified index. Consider adding '".indexOn": "task"' at/to your security and Firebase Database rules for better performance 
Application terminated. 

Hier ist meine Aktivität:

package **********; 

import android.content.Intent; 
import android.support.annotation.NonNull; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.support.v7.widget.LinearLayoutManager; 
import android.support.v7.widget.RecyclerView; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 
import android.content.SharedPreferences; 

import com.firebase.ui.database.FirebaseRecyclerAdapter; 
import com.google.android.gms.common.ConnectionResult; 
import com.google.android.gms.common.api.GoogleApiClient; 
import com.google.firebase.database.DatabaseReference; 
import com.google.firebase.database.FirebaseDatabase; 



public class AimActivity extends AppCompatActivity implements 
     GoogleApiClient.OnConnectionFailedListener{ 

    public static class AimViewHolder extends RecyclerView.ViewHolder{ 
     public TextView aimName; 
     public TextView aimText; 
     public TextView aimUrl; 

     public AimViewHolder(View v){ 
      super(v); 
      aimName = (TextView)itemView.findViewById(R.id.name); 
      aimText = (TextView)itemView.findViewById(R.id.text); 
      aimUrl = (TextView)itemView.findViewById(R.id.url); 
     } 
    } 

    public static final String AIMS = "aims"; 
    private RecyclerView mAimRecyclerView; 
    private LinearLayoutManager mLinearLayoutManager; 

    public static DatabaseReference mFirebaseDatabaseReference; 
    private FirebaseRecyclerAdapter<AimToAim, AimViewHolder> mFirebaseAdapter; 




    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_aim); 

     final Button bProf = (Button) findViewById(R.id.bProf); 

     mAimRecyclerView = (RecyclerView)findViewById(R.id.aimRecyclerView); 
     mLinearLayoutManager = new LinearLayoutManager(this); 
     mLinearLayoutManager.setStackFromEnd(true); 
//  mAimRecyclerView.setLayoutManager(mLinearLayoutManager); 

     //Database Initialization 
     mFirebaseDatabaseReference = FirebaseDatabase.getInstance().getReference(); 
     mFirebaseAdapter = new FirebaseRecyclerAdapter<AimToAim, AimViewHolder>(
       AimToAim.class, 
       R.layout.activity_aim_to_aim, 
       AimViewHolder.class, 
       mFirebaseDatabaseReference.child(AIMS)) { 
      @Override 
      protected void populateViewHolder(AimViewHolder viewHolder, AimToAim model, int position) { 
       viewHolder.aimName.setText(model.getName()); 
       viewHolder.aimText.setText(model.getText()); 
       viewHolder.aimUrl.setText(model.getUrl()); 
      } 
     }; 



     mFirebaseAdapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver(){ 
      @Override 
      public void onItemRangeInserted(int positionStart, int itemCount){ 
       super.onItemRangeInserted(positionStart, itemCount); 
       int aimCount = mFirebaseAdapter.getItemCount(); 
       int lastVisiblePosition = mLinearLayoutManager.findLastCompletelyVisibleItemPosition(); 
       if (lastVisiblePosition == -1 || (positionStart >= (aimCount -1) && lastVisiblePosition == (positionStart -1))){ 
        mAimRecyclerView.scrollToPosition(positionStart); 
       } 
      } 
     }); 
     mAimRecyclerView.setLayoutManager(mLinearLayoutManager); 
     mAimRecyclerView.setAdapter(mFirebaseAdapter); 

     bProf.setOnClickListener(new View.OnClickListener(){ 
      @Override 
      public void onClick(View view) { 
       Intent registerIntent = new Intent(AimActivity.this, UserAreaActivity.class); 
       AimActivity.this.startActivity(registerIntent); 
      } 
     }); 
    } 

    @Override 
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) { 

    } 
} 

und Task-Klasse:

public class Task { 
    private String task; 
    public Task() {} 
    public Task(String task) { 
     this.task = task; 
    } 
    public String getTask() { 
     return task; 
    } 
} 

Answer 1

Sie müssen die .index in Ihre Feuerbasis Regeln in Ihrer Konsole hinzuzufügen:

{ 
    "rules" : { 
     ".read" : ..., 
     ".write" : ..., 
     ".indexOn": "task" 
    } 
}