Need help in debugging of specific weird issue of null object reference error on an EditText object Android

Question

I'm aware about general case of java.lang.NullPointerException, but need help in debugging of this specific case. Please look: I have connected my layout editText with my Java class EditText but still gets an error while trying to get the text from the text field.

I still see this error:

java.lang.NullPointerException: Attempt to invoke virtual method 
'android.text.Editable android.widget.EditText.getText()' on a null object 
reference

and here is my code. at com.ramadanapps.android.fireapp.Register.createUser(Register.java:56)

package com.ramadanapps.android.fireapp;

public class Register extends AppCompatActivity {

private FirebaseAuth mAuth;
private EditText mEmail;
private EditText mPassword;
private Button mRegister;

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

    mEmail = (EditText) findViewById(R.id.signUpEmail);
    mPassword = (EditText) findViewById(R.id.singUpPassword);
    mRegister = (Button) findViewById(R.id.signUpBtn);

    mAuth = FirebaseAuth.getInstance();

    mRegister.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            createUser();
        }
    });
}
@Override
public void onStart(){
    super.onStart();

    FirebaseUser currentUser = mAuth.getCurrentUser();
    if (currentUser != null){
        Toast.makeText(Register.this,"Already signed in", Toast.LENGTH_LONG).show();
    }
}

private void createUser() {
    String email = mEmail.getText().toString();
    String password =  mPassword.getText().toString();

    mAuth.createUserWithEmailAndPassword(email, password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
        @Override
        public void onComplete(@NonNull Task<AuthResult> task) {
            if (task.isSuccessful()){
                Toast.makeText(Register.this,"Successful", Toast.LENGTH_LONG).show();
                startActivity(new Intent(Register.this, MainActivity.class ));
            } else{
                Toast.makeText(Register.this,"Failure", Toast.LENGTH_LONG).show();
            }
        }
    });
}
[![enter image description here][1]][1]}

I don't know where is the problem.

Here is my XML

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.ramadanapps.android.fireapp.Register">

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:inputType="textEmailAddress"
    android:ems="10"
    android:id="@+id/signUpEmail"
    android:layout_alignParentTop="true"
    android:layout_alignParentStart="true"
    android:layout_marginTop="32dp"
    android:hint="Email" />

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:inputType="textPassword"
    android:ems="10"
    android:id="@+id/singUpPassword"
    android:layout_below="@+id/signUpEmail"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="46dp"
    android:hint="Password" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Sign Up"
    android:id="@+id/signUpBtn"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Sign Up"
    android:id="@+id/textView2"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:textSize="25dp" />
</RelativeLayout>

The xml has the id signUpEmail and I don't still know where the problem is.

Are you sure there is an edittext in your xml with the id `signUpEmail`? Post your xml too, also mark line number 56 by adding comment on it. — Nabin Bhandari, Sep 24 '17 at 17:56

Cadet · Accepted Answer · 2017-09-24T19:01:44.523

I installed your code on my side with only 2 differences: 1. I use my own firebase DB 2. My MainActivity is different - actually I created empty one just for testing.

The app works fine - I successfully signed-up several times with diffeent (fake) mails and passwords. Everytime I was passed to main activity, and when pressed "back" - successfully moved back to Register activity. (snapshot attached).

No failures so far. When I failed - it is when tried to sign-up on empty fields of mail or password - it's expected, you need validate the form.

Other possible reason of failure that comes in my mind - is in your main activity. May be there in onStart or onCreate methods you refer to non-defined TextViews? Would you like to share it with corresponding XML?

Thanks and good luck! ))

Need help in debugging of specific weird issue of null object reference error on an EditText object Android

1 Answers1