尝试通过 email firebase 实现发送重置密码时应用程序崩溃

Question

I have made some changes to send a reset pass email to the user. My java code first validates the email and then checks for the email if it exits, if the email exits the reset email must be sent but while i click the app crash my code is good until it checks the email is present or not but its not sending reset email

Java Code

public class forgotpass extends AppCompatActivity {
TextInputLayout regEmail,regUsr;
ProgressDialog progressDialog;
Button forgotPass;
private FirebaseAuth mAuth;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_forgotpass);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
    regEmail=findViewById(R.id.emailfield);
    regUsr=findViewById(R.id.usrnamefield);
    progressDialog = new ProgressDialog(this);

}


private Boolean validateusrEmail() {

    String ews = "[a-zA-Z0-9._-]+@[a-z]+\\.+[a-z]+";
    String val = regEmail.getEditText().getText().toString();
    if (val.isEmpty()) {
        regEmail.setError("Field cannot be empty");
        return false;
    } else if (!val.matches(ews)) {
        regEmail.setError("Invalid Email address");
        return false;
    } else {
        regEmail.setError(null);
        regEmail.setErrorEnabled(false);
        return true;
    }

}
public void changepass(View view)
{
    if(!validateusrEmail())
    {return;}
    else {
        resetByemail();
    }
}
public void frgtUsername(View view)
{
    if(!validateusrEmail())
    {return;}
    else {
        showUsername();
    }
}

private void showUsername() {
}

private void resetByemail() {

    final String enteredEmail = regEmail.getEditText().getText().toString().trim();
    DatabaseReference reference= FirebaseDatabase.getInstance().getReference("users");
    Query checkUser = reference.orderByChild("email").equalTo(enteredEmail);
    checkUser.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            if(dataSnapshot.exists())
            {
                regEmail.setError(null);
                regEmail.setErrorEnabled(false);
                sendPass(enteredEmail);
            }else{
                regEmail.setError("No such email found.Please entered verified email.");
                regEmail.requestFocus();
            }
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

        }
    });

}

private void sendPass(String enteredEmail) {
    progressDialog.setMessage("Sending Email....");
    progressDialog.show();
    mAuth.sendPasswordResetEmail(enteredEmail)
            .addOnCompleteListener(new OnCompleteListener<Void>() {
        @Override
        public void onComplete(@NonNull Task<Void> task) {
            progressDialog.dismiss();
            if(task.isSuccessful()){
                Toast.makeText(forgotpass.this, "Reset Email Sent", Toast.LENGTH_SHORT).show();
            }else{
                Toast.makeText(forgotpass.this, "Failed to send email", Toast.LENGTH_SHORT).show();
            }

        }
    }).addOnFailureListener(new OnFailureListener() {
        @Override
        public void onFailure(@NonNull Exception e) {
            progressDialog.dismiss();
            Toast.makeText(forgotpass.this, ""+e.getMessage(), Toast.LENGTH_SHORT).show();

        }
    });
}

private Boolean validateusrName() {
    String val = regUsr.getEditText().getText().toString();
    if (val.isEmpty()) {
        regUsr.setError("Field cannot be empty");
        return false;
    } else {
        regUsr.setError(null);
        regUsr.setErrorEnabled(false);
        return true;
    }

}
public void onUsernameCheck(View view)
{
    if(!validateusrName())
    {return;}
    else {
        showEmail();
    }
}

private void showEmail() {
}

}

LOG

2020-04-25 18:28:01.537 6414-6414/com.studenthelper.bscithelp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.studenthelper.bscithelp, PID: 6414
java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.android.gms.tasks.Task com.google.firebase.auth.FirebaseAuth.sendPasswordResetEmail(java.lang.String)' on a null object reference
    at com.studenthelper.bscithelp.forgotpass.sendPass(forgotpass.java:109)
    at com.studenthelper.bscithelp.forgotpass.access$000(forgotpass.java:25)
    at com.studenthelper.bscithelp.forgotpass$1.onDataChange(forgotpass.java:91)
    at com.google.firebase.database.Query$1.onDataChange(com.google.firebase:firebase-database@@19.2.1:179)
    at com.google.firebase.database.core.ValueEventRegistration.fireEvent(com.google.firebase:firebase-database@@19.2.1:75)
    at com.google.firebase.database.core.view.DataEvent.fire(com.google.firebase:firebase-database@@19.2.1:63)
    at com.google.firebase.database.core.view.EventRaiser$1.run(com.google.firebase:firebase-database@@19.2.1:55)
    at android.os.Handler.handleCallback(Handler.java:873)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:6692)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

Answer 1

You never initialize your mAuth :

mAuth = FirebaseAuth.getInstance();