Having trouble on username it says null

i got toast null null, it supposed to toast: "Welcome Angelo(username) Dionisio(userSurname)" after logging in but it says "Welcome null null"

after checking the user existance, it supposed to get the name from the database and display to the toast and switch activities...

what is my error?

and i want to store the username, id, usersurname to the shared prefs after displaying the toast in the future..

myLoginActivity.java

public class Login extends AppCompatActivity implements View.OnClickListener {

private EditText editTextEmailPhone;
private EditText editTextPassword;
private Button Login;
private ProgressDialog progressDialog;
Parent_DatabaseHelper mydb;
SQLiteDatabase sqLiteDatabase;
ParentModel parentModel;



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


    editTextEmailPhone = findViewById(R.id.input_username);
    editTextPassword = findViewById(R.id.input_password);
    findViewById(R.id.btn_login).setOnClickListener(Login.this);

    progressDialog = new ProgressDialog(this);

    mydb = new Parent_DatabaseHelper(this);

    sqLiteDatabase = mydb.getReadableDatabase();
}

@Override
public void onClick(View view) {
    switch (view.getId()){
        case R.id.btn_login: {
            userLogin();
            break;
        }

    }


}


private void userLogin() {
    String email = editTextEmailPhone.getText().toString().trim();
    String password = editTextPassword.getText().toString().trim();

    if (email.isEmpty()) {
        editTextEmailPhone.setError("Email or Phone Number is required");
        editTextEmailPhone.requestFocus();
        return;
    }

    if (password.isEmpty()) {
        editTextPassword.setError("Password is required");
        editTextPassword.requestFocus();
        return;
    }
    if (password.length()<6 ){
        editTextPassword.setError("Minimum of length of password should be 6");
        editTextPassword.requestFocus();
        return;
    }

    else{
        progressDialog.setMessage("Please Wait...");
        progressDialog.show();

        boolean exists = mydb.userExistance(email, password);
        if(exists){
            progressDialog.dismiss();
            SharedPrefs.saveSharedSetting(this, "NoAccount", "false");
            Intent intent = new Intent(Login.this, Parent_Home.class);

            ArrayList<ParentModel> arrayList = new ArrayList<>();
            parentModel = new ParentModel();

            String s_parentID;
            String s_parentName;
            String s_parentSurname;

            s_parentID = parentModel.getID();
            s_parentName = parentModel.getName();
            s_parentSurname = parentModel.getSurname();

            Toast.makeText(this, "Welcome " + s_parentName + s_parentSurname, Toast.LENGTH_SHORT).show();
            startActivity(intent);
            finish();
        }
        else {
            Toast.makeText(getApplicationContext(), "Login error", Toast.LENGTH_SHORT).show();
            progressDialog.dismiss();
            return;
        }
    }
}

public void Login_AdminParent(View view) {
    startActivity(new Intent(this, Login_AdminTeacher.class));
}
}

DatabaseHelper.java (incase you need it)

package edu.angelo.parentsportal;

public class Parent_DatabaseHelper extends SQLiteOpenHelper {

public static final String DATABASE_NAME = "Parents_Portal.db";
public static final String TABLE_NAME = "Parents_Table";
public static final String COL_0 = "ID";
public static final String COL_1 = "NAME";
public static final String COL_2 = "SURNAME";
public static final String COL_3 = "EMAIL_ADDRESS";
public static final String COL_4 = "PHONE_NUMBER";
public static final String COL_5 = "PASSWORD";

public Parent_DatabaseHelper(Context context) {
    super(context, DATABASE_NAME, null, 1);

}

@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table " + TABLE_NAME +"(ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, SURNAME TEXT, EMAIL_ADDRESS TEXT, PHONE_NUMBER TEXT, PASSWORD TEXT)");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS "+TABLE_NAME);
onCreate(db);
}

public boolean insertData(String name, String surname, String email_address, String phone_number, String password){
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put(COL_1,name);
    contentValues.put(COL_2,surname);
    contentValues.put(COL_3,email_address);
    contentValues.put(COL_4,phone_number);
    contentValues.put(COL_5,password);
    long result = db.insert(TABLE_NAME, null , contentValues);
    if (result == -1) {
        return false;
    }
    else {
        return true;
    }
}

public ArrayList<ParentModel> getAllParentsData(){
    ArrayList<ParentModel> list = new ArrayList<>();
    String sql = "select * from " + TABLE_NAME;
    SQLiteDatabase mydb = this.getWritableDatabase();
    Cursor cursor = mydb.rawQuery(sql, null);
    if (cursor.moveToFirst()) {
        do {
            ParentModel parentModel = new ParentModel();
            parentModel.setID(cursor.getString(0));
            parentModel.setName(cursor.getString(1));
            parentModel.setSurname(cursor.getString(2));
            parentModel.setEmail(cursor.getString(3));
            parentModel.setPhone_number(cursor.getString(4));
            parentModel.setPassword(cursor.getString(5));
            list.add(parentModel);
        }
        while (cursor.moveToNext());
    }
    return list;
}

public void updateData(int id, String name , String surname , String email , String phone_number , String password){
   ContentValues contentValues = new ContentValues();
    contentValues.put(COL_1, name);
    contentValues.put(COL_2, surname);
    contentValues.put(COL_3, email);
    contentValues.put(COL_4, phone_number);
    contentValues.put(COL_5, password);

    SQLiteDatabase mydb = this.getWritableDatabase();
    mydb.update(TABLE_NAME, contentValues, COL_0 + "=" + id, null);
    mydb.close();
}

public void deleteParent(int id){
    SQLiteDatabase mydb = this.getWritableDatabase();
    mydb.delete(TABLE_NAME, COL_0 + "=" + id, null);
    mydb.close();
}

public boolean userExistance(String emailOrPhone, String pwd) {
    String sql = "select * from " + TABLE_NAME + " where (" + COL_3 + " = '" + emailOrPhone + "' OR " + COL_4 + " = '" + emailOrPhone + "') AND " + COL_5 + " = " + pwd;
    SQLiteDatabase mydb = this.getWritableDatabase();
    Cursor cursor = mydb.rawQuery(sql, null);
    ArrayList<ParentModel> list = new ArrayList<>();
    if (cursor.getCount() > 0) {
        if (cursor.moveToFirst()) {
            do {
                ParentModel parentModel = new ParentModel();
                parentModel.setID(cursor.getString(0));
                parentModel.setName(cursor.getString(1));
                parentModel.setSurname(cursor.getString(2));
                parentModel.setEmail(cursor.getString(3));
                parentModel.setPhone_number(cursor.getString(4));
                parentModel.setPassword(cursor.getString(5));
                list.add(parentModel);
            }
            while (cursor.moveToNext());
        }
        return true;
    }

    else{
        return false;
    }

}
}

Solution

This code here creates ParentModel instance but does not set its members.

    parentModel = new ParentModel();

    String s_parentID;
    String s_parentName;
    String s_parentSurname;

    s_parentID = parentModel.getID();
    s_parentName = parentModel.getName();
    s_parentSurname = parentModel.getSurname();

So s_parentName and s_parentSurname are null.

To fix your problem you should create ParentModel instance before calling userExistance and pass it to userExistance. For example:

. . .
parentModel = new ParentModel();
boolean exists = mydb.userExistance(email, password, parentModel);
. . .

And change userExistance. Add ParentModel parameter and remove parentModel = new ParentModel(); like this:

public boolean userExistance(String emailOrPhone, String pwd, ParentModel parentModel)
{
  String sql = "select * from " + TABLE_NAME + " where (" + COL_3 + " = '" + emailOrPhone + "' OR " + COL_4 + " = '" + emailOrPhone + "') AND " + COL_5 + " = " + pwd;
  SQLiteDatabase mydb = this.getWritableDatabase();
  Cursor cursor = mydb.rawQuery(sql, null);
  ArrayList<ParentModel> list = new ArrayList<>();
  if (cursor.getCount() > 0) {
    if (cursor.moveToFirst()) {
        do {
            parentModel.setID(cursor.getString(0));
            parentModel.setName(cursor.getString(1));
            parentModel.setSurname(cursor.getString(2));
            parentModel.setEmail(cursor.getString(3));
            parentModel.setPhone_number(cursor.getString(4));
            parentModel.setPassword(cursor.getString(5));
            list.add(parentModel);
        }
        while (cursor.moveToNext());
    }
    return true;
}
 return false;

}