Problem I want my user details to be saved in the real time database (Firebase) by using setUpFirebaseAuth() method but i observed that the method is not entering into OnAuthStateChanged() part of the code
Code
package com.example.movies4u;
import static android.content.ContentValues.TAG;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.annotation.SuppressLint;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import com.example.movies4u.Utils.FirebaseMethods;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseAuthUserCollisionException;
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 activity_register extends AppCompatActivity {
TextView HaveAccount;
EditText inputUsername,inputEmail,inputPassword,inputConfirmPassword;
String username,email,password;
Button btnRegister;
FirebaseAuth mAuth;
ProgressBar pb;
private String userID;
private FirebaseAuth.AuthStateListener mAuthListener;
private FirebaseMethods firebaseMethods;
private FirebaseDatabase mFirebaseDatabase;
private DatabaseReference myRef;
private String append;
@SuppressLint("MissingInflatedId")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN); //Hide status Bar
setContentView(R.layout.activity_register);
firebaseMethods =new FirebaseMethods(activity_register.this);
HaveAccount= (TextView) findViewById(R.id.HaveAccount);
pb = findViewById(R.id.progressBar3);
inputUsername=findViewById(R.id.inputUsername);
inputEmail=findViewById(R.id.inputEmail);
inputPassword=findViewById(R.id.inputPassword);
inputConfirmPassword=findViewById(R.id.inputConfirmPassword);
btnRegister=findViewById(R.id.btnRegister);
username=inputUsername.getText().toString();
email=inputEmail.getText().toString();
password=inputPassword.getText().toString();
pb.setVisibility(View.GONE);
HaveAccount.setOnClickListener(view -> {
Intent loginintent=new Intent(activity_register.this,login_activity.class);
startActivity(loginintent);
});
mAuth=FirebaseAuth.getInstance();
btnRegister.setOnClickListener(view -> ValidateDataandDoRegister());
}
private void ValidateDataandDoRegister() {
String username=inputUsername.getText().toString().trim();
String email=inputEmail.getText().toString().trim();
String password=inputPassword.getText().toString().trim();
String confirmPassword=inputConfirmPassword.getText().toString().trim();
if(email.isEmpty()){
inputEmail.setError("Enter Email Address");
inputEmail.requestFocus();
pb.setVisibility(View.GONE);
}
else if(email.length()<10){
inputEmail.setError("Enter valid Email");
inputEmail.requestFocus();
pb.setVisibility(View.GONE);
}
else if(password.isEmpty()){
inputPassword.setError("Enter the password");
inputPassword.requestFocus();
pb.setVisibility(View.GONE);
}
else if(password.length()<8){
inputPassword.setError("Password should be greater than 8 characters");
inputPassword.requestFocus();
pb.setVisibility(View.GONE);
}
else if(confirmPassword.isEmpty()){
inputConfirmPassword.setError("Re-Enter the Password");
inputConfirmPassword.requestFocus();
pb.setVisibility(View.GONE);
}
else if(confirmPassword.length()<8){
inputConfirmPassword.setError("Password should be greater than 8 characters");
inputConfirmPassword.requestFocus();
pb.setVisibility(View.GONE);
}
else if(!password.equals(confirmPassword)){
inputPassword.setError("Password not matched");
inputPassword.requestFocus();
inputConfirmPassword.setError("Password not matched");
inputConfirmPassword.requestFocus();
inputPassword.setText("");
inputConfirmPassword.setText("");
pb.setVisibility(View.GONE);
}
else{
pb.setVisibility(View.VISIBLE);
doRegister(username,email,password);
}
}
private void doRegister(String username,String email, String password) {
pb.setVisibility(View.VISIBLE);
mAuth.createUserWithEmailAndPassword(email, password).addOnSuccessListener(task -> {
if(task != null ){
if(mAuth.getCurrentUser() != null){
userID=mAuth.getCurrentUser().getUid();
}
setupFirebaseAuth();
}
}).addOnFailureListener(e -> {
if(e instanceof FirebaseAuthUserCollisionException){
btnRegister.setEnabled(true);
inputEmail.setError("Email Already Registered");
pb.setVisibility(View.GONE);
inputEmail.requestFocus();
}
else{
btnRegister.setEnabled(true);
pb.setVisibility(View.GONE);
Toast.makeText(activity_register.this, "Oops! Something Went wrong", Toast.LENGTH_SHORT).show();
}
});
}
private void sendVerificationEmail() {
mAuth.getCurrentUser().sendEmailVerification().addOnCompleteListener(task -> {
if(task != null && task.isSuccessful()){
btnRegister.setEnabled(true);
pb.setVisibility(View.GONE);
Toast.makeText(activity_register.this, "Email has been sent to your email address", Toast.LENGTH_SHORT).show();
}
else {
btnRegister.setEnabled(true);
pb.setVisibility(View.GONE);
Toast.makeText(getApplicationContext(), "Oops! failed to send verification email",Toast.LENGTH_SHORT).show();
}
});
}
/*
------------------------------------ Firebase ---------------------------------------------
*/
/**
* Setup the firebase auth object
*/
private void setupFirebaseAuth(){
Log.d(TAG, "setupFirebaseAuth: setting up firebase auth.");
mAuth = FirebaseAuth.getInstance();
mFirebaseDatabase = FirebaseDatabase.getInstance();
myRef = mFirebaseDatabase.getReference();
//cannot get into this part of code
mAuthListener = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
FirebaseUser user=firebaseAuth.getCurrentUser();
if (user != null) {
// User is signed in
Log.d(TAG, "onAuthStateChanged:signed_in:" + user.getUid());
myRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
//1st check: Make sure the username is not already in use
if(firebaseMethods.checkIfUsernameExists(username, dataSnapshot)){
//to randomly generate key to make sure username is unique
append = myRef.push().getKey().substring(3,10);
Log.d(TAG, "onDataChange: username already exists. Appending random string to name: " + append);
}
username = username + append;
//add new user to the database
firebaseMethods.addNewUser(email, username);
Toast.makeText(activity_register.this, "SignUp successful", Toast.LENGTH_SHORT).show();
}
@Override
public void onCancelled(DatabaseError databaseError) {
Toast.makeText(activity_register.this, "unsuccessful", Toast.LENGTH_SHORT).show();
}
});
finish();
} else {
// User is signed out
Toast.makeText(activity_register.this, "unsuccessful", Toast.LENGTH_SHORT).show();
Log.d(TAG, "onAuthStateChanged:signed _out");
}
// ...
}
};
}
@Override
public void onStart() {
super.onStart();
}
@Override
public void onStop() {
super.onStop();
if (mAuthListener != null) {
mAuth.removeAuthStateListener(mAuthListener);
}
}
}
FirebaseMethods
```
package com.example.movies4u.Utils;
import android.content.Context;
import android.util.Log;
import android.widget.Toast;
import androidx.annotation.NonNull;
import com.example.movies4u.Models.User;
import com.example.movies4u.Models.UserAccountSettings;
import com.example.movies4u.R;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
public class FirebaseMethods {
private static final String TAG="FirebaseMethods";
//Firebase
private FirebaseAuth mAuth;
private FirebaseAuth.AuthStateListener mAuthListener;
private FirebaseDatabase mFirebaseDatabase;
private DatabaseReference myRef;
private String userID;
private Context mContext;
public FirebaseMethods(Context context){
mAuth=FirebaseAuth.getInstance();
mFirebaseDatabase =FirebaseDatabase.getInstance();
myRef=mFirebaseDatabase.getReference();
mContext =context;
if(mAuth.getCurrentUser() !=null){
userID =mAuth.getCurrentUser().getUid();
}
}
public boolean checkIfUsernameExists(String username, DataSnapshot dataSnapshot){
User user =new User();
for (DataSnapshot ds: dataSnapshot.child(userID).getChildren()){
user.setUsername(ds.getValue(User.class).getUsername());
if(StringManipulation.expandUsername(user.getUsername()).equals(username)){
return true;
}
}
return false;
}
/**
* Registering a new email and password
* @param username
* @param email
* @param password
*/
public void registerNewEmail(final String username,final String email,String password){
mAuth.createUserWithEmailAndPassword(email, password)
.addOnCompleteListener(new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if(!task.isSuccessful()){
Toast.makeText(mContext, R.string.auth_failed, Toast.LENGTH_SHORT).show();
}
else if(task.isSuccessful()){
userID=mAuth.getCurrentUser().getUid();
}
}
});
}
public void addNewUser(String email, String username){
User user=new User(email,username);
if(userID!=null)
{
myRef.child(mContext.getString(R.string.dbname_users))
.child(userID)
.setValue(user).addOnSuccessListener(new OnSuccessListener<Void>() {
@Override
public void onSuccess(Void unused) {
Log.d(TAG, "user added");
Toast.makeText(mContext, "user added", Toast.LENGTH_SHORT).show();
}
}).addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Log.d(TAG, "user not added");
Toast.makeText(mContext, e.getMessage(), Toast.LENGTH_SHORT).show();
}
});
UserAccountSettings settings = new UserAccountSettings(username, username);
myRef.child(mContext.getString(R.string.dbname_user_account_settings))
.child(userID)
.setValue(settings);
}
else {
Log.d(TAG, "user is null");
}
}
}
```
I tried directly calling my method firebaseMethods.addNewUser(email, username); but I am getting an error in addNewUser method as UserId is null. I am expecting to make sure that the User details gets added in database just after the user clicks the register button by making sure that the UserId is not null.
Tried
adding mAuth.addAuthStateListener(mAuthListener) method in onStart method
Error
Shows a null pointer exception in logcat, when i try to start the register activity
Logcat message
FATAL EXCEPTION: main
Process: com.example.movies4u, PID: 6821
java.lang.NullPointerException: Attempt to invoke interface method 'void com.google.firebase.auth.FirebaseAuth$AuthStateListener.onAuthStateChanged(com.google.firebase.auth.FirebaseAuth)' on a null object reference
at com.google.firebase.auth.zzl.run(com.google.firebase:firebase-auth@@21.0.3:1)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:224)
at android.app.ActivityThread.main(ActivityThread.java:7081)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:604)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:928)
