java.lang.NullPointerException Firebase

Question

I have been suffering from this problem 2 days and i can't solve it

I have this code

public class SettingsActivity extends AppCompatActivity {
 private DatabaseReference mUserDatabase;
 private FirebaseUser mCurrentUser;
 //Android Layout

 private CircleImageView mDisplayImage;
 private TextView mName;
 private TextView mStatus;
 private Button mStatusBtn;
 private Button mImageBtn;
 private static final int GALLERY_PICK = 1;

 // Storage Firebase
 private ProgressDialog mProgressDialog;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_settings);

     mDisplayImage = (CircleImageView) findViewById(R.id.settings_image);
     mName = (TextView) findViewById(R.id.settings_name);
     mStatus = (TextView) findViewById(R.id.settings_status);
     mStatusBtn = (Button) findViewById(R.id.settings_status_btn);
     mImageBtn = (Button) findViewById(R.id.settings_image_btn);
     mCurrentUser = FirebaseAuth.getInstance().getCurrentUser();

     String current_uid = mCurrentUser.getUid();
     mUserDatabase = FirebaseDatabase.getInstance().getReference().child("Users").child(current_uid);
     mUserDatabase.keepSynced(true);
     mUserDatabase.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            String name = dataSnapshot.child("name").getValue().toString();
            final String image = dataSnapshot.child("image").getValue().toString();
            String status = dataSnapshot.child("status").getValue().toString();
            String thumb_image = dataSnapshot.child("thumb_image").getValue().toString();
            mName.setText(name);
            mStatus.setText(status);
        }
        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

        }
    });
 }
}

In my log i got this problem

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.pc.newchatj, PID: 724 java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Object.toString()' on a null object reference at com.example.pc.newchatj.SettingsActivity$1.onDataChange(SettingsActivity.java:74) at com.google.firebase.database.core.ValueEventRegistration.fireEvent(com.google.firebase:firebase-database@@16.0.4:75) at com.google.firebase.database.core.view.DataEvent.fire(com.google.firebase:firebase-database@@16.0.4:63) at com.google.firebase.database.core.view.EventRaiser$1.run(com.google.firebase:firebase-database@@16.0.4:55) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5254) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

Here is my FirebaseDatabase screen

Can any onw help please , Thanks !!!

This means that .getValue() on one of the properties inside the onDataChange function is returning null. — Mark
– Mark, Commented Oct 29, 2018 at 14:06
@TheWanderer There's a space after name, but yes that's what I figure should work aswell. — Mark
– Mark, Commented Oct 29, 2018 at 14:16

Martin Zeitler · Accepted Answer · 2018-10-29 14:35:07Z

4

remove the " double quotes & _ spaces from Firebase field names name and status.

edited Oct 29, 2018 at 14:35

answered Oct 29, 2018 at 14:16

Martin Zeitler

79.6k20 gold badges169 silver badges243 bronze badges

Sign up to request clarification or add additional context in comments.

9 Comments

TheWanderer Over a year ago

Looks like there are manually added quotes in the values as well.

TheWanderer Over a year ago

I don't think Firebase puts quotes around anything in the console display.

TheWanderer Over a year ago

I'm also curious how OP is setting the data.If it's done programmatically, that code needs to be fixed.

Martin Zeitler Over a year ago

@TheWanderer the quotes around string data are correct; just checked.

Martin Zeitler Over a year ago

@TheWanderer field names and numeric values have no quotes there... strings do.

|

Gastón Saillén · Accepted Answer · 2018-10-29 17:20:11Z

Adding to Martin answer, you can also do this

String name = dataSnapshot.child("name").getValue(String.class);

instead of this

String name = dataSnapshot.child("name").getValue().toString();

Also, always make sure that your reference is matching exactly your data at your Firebase Console and always use

if(dataSnapshot.exists()){....}

before getting any results, so you can catch any problems there

for example

    if(dataSnapshot.exists()){
    String name = dataSnapshot.child("name").getValue().toString();
                final String image = dataSnapshot.child("image").getValue().toString();
                String status = dataSnapshot.child("status").getValue().toString();
                String thumb_image = dataSnapshot.child("thumb_image").getValue().toString();
                mName.setText(name);
                mStatus.setText(status);

    }
  ...

Collectives™ on Stack Overflow

java.lang.NullPointerException Firebase

2 Answers 2

9 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

9 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related