Preferences created in Android Studio with connection to Firebase is not persisting

Question

We have just started to develop an application. We have opted to connect to the Firebase database using email user and password. Logging in and creating new users is working normally, however, my Preferences class is not saved, and every time I close the app, it asks for the user and password again. How do I get it saved in the application’s "memory"?

My Login class (called Mainactivity):

package e.servidor.myapplication.Activity;

import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.SharedLibraryInfo;
import android.preference.Preference;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;

import java.security.PrivateKey;
import java.security.PublicKey;
import java.util.prefs.Preferences;

import e.servidor.myapplication.DAO.ConfiguracaoFirebase;
import e.servidor.myapplication.Entidades.Usuarios;
import e.servidor.myapplication.Helper.Preferencias;
import e.servidor.myapplication.R;

public class MainActivity extends AppCompatActivity {
    private Button buttonlogin;
    private EditText editTextsenha;
    private EditText editTextemail;
    private TextView textViewcliqueaqui;
    private FirebaseAuth autenticacao;
    private Usuarios usuarios;


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

        editTextemail = (EditText) findViewById(R.id.editTextemail);
        editTextsenha = (EditText) findViewById(R.id.editTextsenha);
        textViewcliqueaqui = (TextView) findViewById(R.id.textViewcliqueaqui);
        buttonlogin = (Button) findViewById(R.id.buttonlogin);

        buttonlogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (!editTextemail.getText().toString().equals("") && !editTextsenha.getText().toString().equals("")) {

                    usuarios = new Usuarios();
                    usuarios.setEmail(editTextemail.getText().toString());
                    usuarios.setSenha(editTextsenha.getText().toString());
                    validarLogin();



                } else {
                    Toast.makeText(MainActivity.this, "Por favor, preencha os campos de E-mail e Senha.", Toast.LENGTH_LONG).show();

                }
            }
        });

        textViewcliqueaqui.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                abreCadastroUsuario();
            }
        });

    }

    private void validarLogin(){

        autenticacao = ConfiguracaoFirebase.getFirebaseAutenticacao();
        autenticacao.signInWithEmailAndPassword(usuarios.getEmail(), usuarios.getSenha()).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
            @Override
            public void onComplete(@NonNull Task<AuthResult> task) {

                if (task.isSuccessful()) {
                    Toast.makeText(MainActivity.this, "Login efetuado com sucesso.", Toast.LENGTH_LONG).show();
                    abrirTelaPrincipal();


                } else {
                    Toast.makeText(MainActivity.this, "E-mail ou Senha incorretos.", Toast.LENGTH_LONG).show();

                }finish();

            }
        });

    }

    public void abrirTelaPrincipal(){
        Intent intentAbrirTelaPrincipal = new Intent(MainActivity.this, telaprincipal.class);
        startActivity(intentAbrirTelaPrincipal);
    }

    public void abreCadastroUsuario(){
        Intent intent = new Intent(MainActivity.this, cadastro.class);
        startActivity(intent);
    }

}

My class Preferences:

package e.servidor.myapplication.Helper;

import android.content.Context;
import android.content.SharedPreferences;

public class Preferencias {


    private Context context;
    private SharedPreferences preferences;
    private String NOME_ARQUIVO = "myapplication.preferences";
    private int MODE=0;
    private SharedPreferences.Editor editor;

    private final String CHAVE_IDENTIFICADOR = "IdentificadorUsuarioLogado";
    private final String CHAVE_EMAIL = "EmailUsuarioLogado";

    public  Preferencias(Context context) {
        this.context=context;
        preferences = context.getSharedPreferences(NOME_ARQUIVO,Context.MODE_PRIVATE);
        editor.apply();
    }

    public void SalvarUsuarioPreferencias (String IdentificadorUsuario, String IdentificadorEmail) {
        editor.putString(CHAVE_IDENTIFICADOR, IdentificadorUsuario);
        editor.putString(CHAVE_EMAIL, IdentificadorEmail);
        editor.commit();
    }

    public String getIdentificador(){ 

        return preferences.getString(CHAVE_IDENTIFICADOR,null);
    }
    public String getEmail() {
        return preferences.getString(CHAVE_EMAIL, null);
    }
}

My Class of Users:

package e.servidor.myapplication.Entidades;

import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.Exclude;

import java.util.HashMap;
import java.util.Map;

import e.servidor.myapplication.DAO.ConfiguracaoFirebase;

public class Usuarios {
    private String id;
    private String email;
    private String senha;


    public Usuarios() {
    }

    public void salvar(){
        DatabaseReference referenciaFirebase = ConfiguracaoFirebase.getFirebase();
        referenciaFirebase.child("usuario").child(String.valueOf(getId())).setValue(this);
    }

    public Map<String, Object> toMap () {
        HashMap<String, Object> HasMapUsuario = new HashMap<>();

        HasMapUsuario.put("id", getId());
        HasMapUsuario.put("email", getEmail());
        HasMapUsuario.put("senha", getSenha());
        return HasMapUsuario;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getSenha() {
        return senha;
    }

    public void setSenha(String senha) {
        this.senha = senha;
    }
}

Answer 1

I think the problem is this, you are not checking if the Firebase user instance is with any logged-in user. When vc enters the login screen, it does not check if a logged-in user then logs in again and overwrites the user instance. Put this code on the oncreate of your login Activity

FirebaseAuth mAuth = FirebaseAuth.getInstance();

try {
    Log.i("Entrou","Entrou no diferente de nulo" + " " + mAuth.getCurrentUser().getUid());
    startActivity(new Intent(getApplicationContext(),MenuOrdemServico.class));
}catch (NullPointerException n) {
    // entrou no catch, mAuth == null
}