The Activity restart after saving data in Firebase

Issue

Im trying to save user information in Firebase Database but a strange behavior happens that make the Save button to restart the same activity not the Intent that i made for the next activity .

 public void userData () {
    user.setFName(Fname.getText().toString());
    user.setLName(Lname.getText().toString());
    user.setEmail(Email.getText().toString());
    user.setAddress(userAddress.getText().toString());
    user.setPassword(UserInfo.getString("Password", ""));
    user.setID(CicID.getText().toString());
    user.setUsername(Usnm.getText().toString());
    if (bAdmn.isChecked()) user.setMajor("Business Administrator");
    if (BTech.isChecked()) user.setMajor("Business Tech");
    if (masscom.isChecked()) user.setMajor("Mass Com");
    if (Eng.isChecked()) user.setMajor("Engineering");

    final String us = user.getUsername();
    Log.i("Username", us);
    MyDatabase1.child("USERS").child(us).setValue(user);
    Intent i = new Intent(getApplicationContext() , chooseCoursesActivity.class);
    startActivity(i);

}

that is the method for save button , Note that i want to update the user information in a profile Activity if the user wants to change his First name or Last name or something . But after Clicking save button , the data is saved correctly but the intent never done . it recreate the same Activity . in the Login activity there is aLogin button which checks username and password then attempt to log in based on data ,if login successful it goes to that Profile Activity . Save button in Profile Activity re Do the method in Login button in Login Activity which checks everything and goes to Profile Activity which what causing the Re Create Problem . Here is the code for login button :

    MyDatabase = FirebaseDatabase.getInstance().getReference();
    MyDatabase.child("USERS").addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            boolean exists = false;

            for (DataSnapshot child : dataSnapshot.getChildren()) {
                final Map<String, Object> model = (Map<String, Object>) child.getValue();

                if (model.get("username").equals(Username.getText().toString())) {
                    exists = true;
                    Log.i("USername"," Correct");


                    if(exists){
                        MyDatabase.child("USERS").orderByChild("username").equalTo(Username.getText().toString())

                                .addListenerForSingleValueEvent(new ValueEventListener() {
                            @Override
                            public void onDataChange(DataSnapshot dataSnapshot) {

                                for (DataSnapshot child :dataSnapshot.getChildren()){
                                    Log.i("Password",child.getValue().toString());
                                   Log.i( "Password",child.child("password").toString());
                                    if(password.getText().toString().equals(child.child("password").getValue())){
                                        Log.i("LOGIN","Success");
                                         loginsuccessful = true ;

                                    if(loginsuccessful){

                                        saveCredntials(Username.getText().toString(),password.getText().toString());


                                        Intent i2 = new Intent(getApplicationContext(), ProfileActivity.class);
                                        i2.putExtra("loginStats",IsLoggedIn);
                                        i2.putExtra("Username",Un);

                                        i2.putExtra("Password",Pw);


                                        startActivity(i2);
                                        finish();}
                                    }else{
                                        Log.i("LOGIN","Failed");
                                        loginsuccessful= false ;

                                    }

                                }

                            }

                            @Override
                            public void onCancelled(DatabaseError databaseError) {
                                            Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();
                            }
                        });
                    }
                    break;

                }else {
                    Log.i("LOGIN","FAiled");

                }

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

        }
    });
}

Sorry for making this too long but i dont know the problem .

Solution

I just solved this problem! According to your case, please avoid using addValueEventListener, because it will listen to all changes you make to the database. That's why every time you make any change to the database, the code in the addValueEventListener (startActivity) will be executed no matter you call that login function or not.

My suggestion is using addListenerForSingleValueEvent instead of addValueEventListener (Make sure you change ALL the addValueEventListener in your Android project to addListenerForSingleValueEvent), or you can even remove the listener if you don't really need it. I don't know if it is a good design, but it should be able to solve your problem.

Answered By - hiro tang