Why does the getter return null?

Question

In my android studio project I have a class of getters and setters to help me, but for some reason on main Activity when I call the db.busca() (which is in the database operations class) which places a token in the u.setToken("comes from comic book").

Then on Mainactivity if I give user.getToken() it comes null, I’ve had to test if I give a user.getToken() in the Database class everything works ok, but in Mainactivity results null.

In some cases I want it to return null but when it should not return null and yes a token it returns null

Class of the Database:

    public void busca(){
    String[] colunas = new String[]{"token", "nome"};
    Cursor cursor = db.query("user", colunas, null, null, null, null, "token ASC");
    if(cursor.getCount() > 0){
        cursor.moveToFirst();
        do{
            Utilizador u = new Utilizador();
            u.setToken(cursor.getString(0));
            u.setNome(cursor.getString(1));
        }while(cursor.moveToNext());
    }
}

User class:

package imm.pt.immflix;

    public class Utilizador {
        private String nome;
        private String mail;
        private String token;
        private String foto;
        private int typeService;

        public String getNome() {
            return nome;
        }

        public void setNome(String nome) {
            this.nome = nome;
        }

        public String getMail() {
            return mail;
        }

        public void setMail(String mail) {
            this.mail = mail;
        }

        public String getToken() {
            return token;
        }

        public void setToken(String token) {
            this.token = token;
        }

        public String getFoto() {
            return foto;
        }

        public void setFoto(String foto) {
            this.foto = foto;
        }

        public int getTypeService() {
            return typeService;
        }

        public void setTypeService(int typeService) {
            this.typeService = typeService;
        }
    }

Mainactivity class:

        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            getSupportActionBar().hide();
            TextView tvtitle = findViewById(R.id.tvTitle);
            ObjectAnimator anime = ObjectAnimator.ofFloat(tvtitle, "alpha", 0f, 1f);
            anime.setDuration(2000);
            anime.start();
            DB db = new DB(this);
            db.busca();
            Utilizador user = new Utilizador();
            token = user.getToken();
            if(token == null){
                Handler handler = new Handler();
                handler.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        Intent intent = new Intent(MainActivity.this, Login.class);
                        intent.putExtra("isNew", true);
                        startActivity(intent);
                        finish();
                    }
                }, 3000);
            }else{
                Handler handler = new Handler();
                handler.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        Intent intent = new Intent(MainActivity.this, Login.class);
                        intent.putExtra("isNew", false);
                        startActivity(intent);
                        finish();
                    }
                }, 3000);
            }

        }

Answer 1

The user.getToken() is being used right after object instantiation user.

Utilizador user = new Utilizador();
token = user.getToken();

As no value has been assigned to the field token user.getToken() returns null.

With the elements made available I believe that the method busca() should return a User to be used in the Activity class:

public Utilizador busca(){
    String[] colunas = new String[]{"token", "nome"};
    Cursor cursor = db.query("user", colunas, null, null, null, null, "token ASC");
    if(cursor.getCount() > 0){
        cursor.moveToFirst();
        do{
            Utilizador u = new Utilizador();
            u.setToken(cursor.getString(0));
            u.setNome(cursor.getString(1));
        }while(cursor.moveToNext());
        return u;
    }
    return null;
}

The code in Activity should be changed to:

DB db = new DB(this);
Utilizador user = db.busca();

Since there is the possibility of the query returning nothing, add a test to verify this.

I don’t know if the query can return more than one User or not, if it returns, the method should return a User list.

I wasn’t looking for anything else "wrong".