search database

private void getUserAnswer() {

        FirebaseDatabase.getInstance().getReference().child("Users")
                .addListenerForSingleValueEvent(new ValueEventListener() {
                    @Override
                    public void onDataChange(DataSnapshot dataSnapshot) {
                        for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
                            if(snapshot.hasChild("email")) {
                                String mails = snapshot.child("email").getValue().toString();
                                if (mails.equals(currentUserMail)) {
                                    if ((snapshot.hasChild("answer")) && snapshot.hasChild("question")) {
                                        userAnswer = snapshot.child("answer").getValue().toString();
                                        currentUserID = snapshot.child("uid").getValue().toString();
                                        String question = snapshot.child("question").getValue().toString();
                                        questionView.setText(question);
                                    } else {
                                        Toast.makeText(ForgotPasswordActivity.this, "You have not set up a security question. Please create a new account.", Toast.LENGTH_LONG).show();
                                    }

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