Validation Password Android Studio

On one screen I register the password (button register) and on the other screen I need it to be validated for the application to shut down (button off).

I have tried in many ways, but I can not get the database password to do this validation, I can only validate with a default password.

FIRST SCREEN (Where password is saved)

//Expecificação
EditText editEmail, editSenha; //componetntes do projeto
SQLiteDatabase db; //DB é o banco de dados

//SharedPreferences


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

    if (getIntent().getBooleanExtra("Exit", false)){
        finish();
    }


    editEmail=(EditText)findViewById(R.id.editEmail);
    editSenha=(EditText)findViewById(R.id.editSenha);

    db=openOrCreateDatabase("CadastroDB", Context.MODE_PRIVATE, null);
    db.execSQL("CREATE TABLE IF NOT EXISTS cadastro (Email VARCHAR, Senha VARCHAR);");

}

//Botão Cadastrar

public void startDesligar (View view) {

    if(isEmailValid(editEmail.getText().toString().trim()) && isPasswordValid(editSenha.getText().toString().trim()))
    {
        db.execSQL("INSERT INTO cadastro VALUES('" + editEmail.getText() + "','" + editSenha.getText() + "');");
        showMessage("Tudo certo!", "Dados Gravados");
        clearText();
        Toast.makeText(getApplicationContext(), "Redirecionando...", Toast.LENGTH_LONG).show();
        Intent Desligar = new Intent(this, Desligar.class);
        startActivity(Desligar);
    } else {
        showMessage("Preencha os campos corretamente!", "E-mail/Senha inválido");
    }
}

//ShowMessage

public void showMessage(String title, String message)
{
    AlertDialog.Builder builder=new AlertDialog.Builder(this);
    builder.setCancelable(true);
    builder.setTitle(title);
    builder.setMessage(message);
    builder.show();
}

//ClearText

public void clearText()
{
    editEmail.setText("");
    editSenha.setText("");
}

private boolean isEmailValid (String email) {
    Pattern pattern;
    Matcher matcher;

    final String EMAIL_PATTERN = (".+@.+\.[a-z]+");

    pattern = Pattern.compile(EMAIL_PATTERN);
    matcher = pattern.matcher(email);

    return matcher.matches();
}

private boolean isPasswordValid (String password) {

    Pattern pattern;
    Matcher matcher;

    final String PASSWORD_PATTERN = "^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=\S+$).{4,}$";

    pattern = Pattern.compile(PASSWORD_PATTERN);
    matcher = pattern.matcher(password);

    return matcher.matches();
}

}

SECOND SCREEN (where I use the password to turn off)

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_desligar); // Determina qual layout vai abrir

    senha = (EditText)findViewById(R.id.editSenha); // Senha = EditSenha

    tentativas = (EditText)findViewById(R.id.editTentativas); // Tentativa = editTentativas

    btnir = (Button)findViewById(R.id.button);
}

public void startRecuperacao (View view) {

    Intent Recuperacao = new Intent(this, Recuperacao.class);
    startActivity(Recuperacao);
}

public void btndesligar (View view) {
    if
            (senha.getText().toString().equals("senha digitada")) {
        Intent intent = new Intent(this, CadastroActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        intent.putExtra("Exit", true);
        Toast.makeText(getApplicationContext(), "Desligando...", Toast.LENGTH_SHORT).show();
        startActivity(intent);
        finish();
    } else {
        Toast.makeText(getApplicationContext(), "Senha Incorreta", Toast.LENGTH_SHORT).show();
        tentativas.setVisibility(View.VISIBLE); //Deixar o texto com o número de tentativas
        counter--;
        tentativas.setText(Integer.toString(counter));

        if (counter == 0) {
            btnir.setEnabled(false); //Desabilitar o botão de Desligar
        }
    }

}

}