Android EventListenerが起動していない

Question

現在、私は自分のfirebaseデータベースに既にある場所オブジェクトを取得しようとしています：Articベースとlocaleobjに保存しますが、何らかの理由でプログラムを実行しますlocaleobjがnullであると言ってきます。リスナーを正しくやっていますか？ここで

package com.example.spy; 

import android.support.v7.app.AppCompatActivity; 

import android.os.Bundle; 

import java.util.ArrayList; 
import java.util.Random; 

import android.content.Intent; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 

import com.google.firebase.auth.FirebaseAuth; 
import com.google.firebase.auth.FirebaseUser; 
import com.google.firebase.database.DataSnapshot; 
import com.google.firebase.database.DatabaseError; 
import com.google.firebase.database.DatabaseReference; 
import com.google.firebase.database.FirebaseDatabase; 
import com.google.firebase.database.ValueEventListener; 

public class GameJoin extends AppCompatActivity implements View.OnClickListener { 
    private FirebaseDatabase database; 
    private DatabaseReference myRef; 
    private FirebaseUser user; 

    private TextView location; 
    private TextView role; 
    private TextView desc; 

    private Button back; 

    private Intent extra; 
    private Bundle data; 

    private String spy; 

    private Location localeObj; 

    private String game_code; 

    private Random rand; 

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

     rand = new Random(); 

     //Firebase stuff 
     user = FirebaseAuth.getInstance().getCurrentUser(); 
     database = FirebaseDatabase.getInstance(); 
     myRef = database.getReference(); 

     //Views 
     role = (TextView) findViewById(R.id.label_role); 
     location = (TextView) findViewById(R.id.label_location); 
     desc = (TextView) findViewById(R.id.descriptionText); 

     //Buttons 
     back = (Button) findViewById(R.id.button3); 

     //Attach a listener to the button 
     findViewById(R.id.button3).setOnClickListener(this); 

     //Retrieve data from previous activity 
     extra = getIntent(); 
     data = extra.getBundleExtra("game_data"); 
     game_code = data.getString("game_code"); 

     //TODO: Pull location object from Firebase 
     myRef.child("lobby").child(game_code).child("location").addValueEventListener(new ValueEventListener() { 

      @Override 
      public void onCancelled(DatabaseError error) { 
      System.out.println("************************IN CANCELLED*************************************"); 
      } 

      @Override 
      public void onDataChange(DataSnapshot dataSnapshot) { 
       System.out.println("************************OUTSIDE IF*************************************"); 
       for (DataSnapshot data : dataSnapshot.getChildren()) { 
        localeObj = dataSnapshot.getValue(Location.class); 
        System.out.println("************************IN IF*************************************"); 
       } 
      } 
     }); 

     myRef.child("lobby").child(game_code).child("spy").addValueEventListener(new ValueEventListener() { 

      @Override 
      public void onCancelled(DatabaseError error) { 

      } 

      @Override 
      public void onDataChange(DataSnapshot dataSnapshot) { 
       for (DataSnapshot data : dataSnapshot.getChildren()) { 
        spy = (String) dataSnapshot.getValue(String.class); 
       } 
      } 
     }); 

     //Display a special UI if the user is a spy 
     if (user.getEmail().equals(spy)) { 
      role.setText("You are the spy. Don't get caught!"); 
      location.setText("Mystery Location"); 
      desc.setText("Welcome to Spy Fall. Keep your identity hidden for the length of the game, or figure out what the location is to win the game."); 
     } else { 
      role.setText(localeObj.getRole(rand.nextInt(3))); 
      location.setText(localeObj.getLocationName()); 
      desc.setText("Welcome to Spy Fall. Infer who is the spy before time runs out in order to win the game."); 
     } 

    } 


    @Override 
    public void onClick(View v) { 
     //Stuff happens when buttons are clicked 
     int id = v.getId(); 
     if (id == R.id.button3) { 
      //Clean up old game lobby information 
      myRef = database.getReference("lobby"); 
      myRef.child(game_code).child("players").child(user.getUid()).removeValue(); //Remove all data associated with the current game 

      //Return to the main lobby 
      Intent main_lobby = new Intent(GameJoin.this, MainActivity.class); 
      startActivity(main_lobby); 
     } 
    } 
} 

は、私があまりにも

               --------- beginning of crash 
05-09 11:01:42.718 3083-3083/com.example.spy E/AndroidRuntime: FATAL EXCEPTION: main 
                   Process: com.example.spy, PID: 3083 
                   java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.spy/com.example.spy.GameJoin}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.example.spy.Location.getRole(java.lang.Integer)' on a null object reference 
                    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$H.handleMessage(ActivityThread.java:1477) 
                    at android.os.Handler.dispatchMessage(Handler.java:102) 
                    at android.os.Looper.loop(Looper.java:154) 
                    at android.app.ActivityThread.main(ActivityThread.java:6119) 
                    at java.lang.reflect.Method.invoke(Native Method) 
                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 
                   Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.example.spy.Location.getRole(java.lang.Integer)' on a null object reference 
                    at com.example.spy.GameJoin.onCreate(GameJoin.java:112) 
                    at android.app.Activity.performCreate(Activity.java:6679) 
                    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118) 
                    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618) 
                    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)  
                    at android.app.ActivityThread.-wrap12(ActivityThread.java)  
                    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)  
                    at android.os.Handler.dispatchMessage(Handler.java:102)  
                    at android.os.Looper.loop(Looper.java:154)  
                    at android.app.ActivityThread.main(ActivityThread.java:6119)  
                    at java.lang.reflect.Method.invoke(Native Method)  
                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)  
                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)  

https://gyazo.com/2b0c1ee92f365f06b1737c99793c96b3 を取得TomcatのメッセージであるIVEは、locationName次のコードを使用してください取得したい場合は、私のデータベース構造があまりにも

Answer 1

どのように見えるか投稿しました：

myRef.child("lobby").child(game_code).child("location").addValueEventListener(new ValueEventListener() { 

    @Override 
    public void onCancelled(DatabaseError error) { 
     System.out.println("************************IN CANCELLED*************************************"); 
    } 

    @Override 
    public void onDataChange(DataSnapshot dataSnapshot) { 
     System.out.println("************************OUTSIDE IF*************************************"); 
     String locationName = (String) dataSnapshot.child("locationName").getValue(); 
    } 
}) 

希望lps。