I want to save with shared preference but the app crashes

Question

I want to make an app that basically the user inputs some strings inside a

 <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:orientation="horizontal">

    <com.google.android.material.textfield.TextInputLayout

        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="2"
        android:textColorHint="#ffffff"
        app:errorEnabled="true">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/texto"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:backgroundTint="#4249ff"
            android:hint="@string/BtnO"
            android:textColor="#ffffff" />
    </com.google.android.material.textfield.TextInputLayout>

    <Button
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:onClick="confirmInput"
        android:text="@string/Btns" />

</LinearLayout>

So when the user presses the confirm button I want it to be saved but the app crashes instead its the first time I'm using shared preferences and I don't really understand it.I doesn't save the value the user.Also I know I have used hint but with my shared preferences it changes the hint into a text instead of it staying like that. Here is my java code:

public class MainActivity extends AppCompatActivity {
    private EditText nameInput;
    private EditText homeInput;
    private SharedPreferences prefs;

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

        SharedPreferences prefs= getSharedPreferences("my_data",MODE_PRIVATE);
        String name = prefs.getString("MY_NAME","name");
        String home = prefs.getString("MY_HOME","home");

        ((EditText)findViewById(R.id.texto)).setText(name);
        ((EditText)findViewById(R.id.textd)).setText(home);

        nameInput =(EditText)findViewById(R.id.texto);
        nameInput =(EditText)findViewById(R.id.textd);

    }

    public void copy(View view) {
    }

    public void confirmInput(View view) {
        String name=nameInput.getText().toString();
        SharedPreferences.Editor editor = prefs.edit();
        editor.putString("MY_NAME",name);
        editor.apply();
    }
    public void confirmInput2(View view) {
        String home=homeInput.getText().toString();
        SharedPreferences.Editor editor=prefs.edit();
        editor.putString("MY_HOME",home);
        editor.apply();
    }

}

You should start by getting the stack trace from the Android logcat. This will tell you which line of code causes the crash. — Code-Apprentice, Mar 23 '20 at 20:43

score 0 · Accepted Answer · answered Mar 23 '20 at 20:50

I think the error is because there are two declarations of SharedPreferences prefs one in the onCreate method level and another in the beginning of the class

The error would be fix just by removing the prefs declaration onCreate and just use the variable defined in the beginning of the class as below

   @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //Take a look here!
    this.prefs= getSharedPreferences("my_data",MODE_PRIVATE);
    String name = prefs.getString("MY_NAME","name");
    String home = prefs.getString("MY_HOME","home");

    ((EditText)findViewById(R.id.texto)).setText(name);
    ((EditText)findViewById(R.id.textd)).setText(home);

    nameInput =(EditText)findViewById(R.id.texto);
    nameInput =(EditText)findViewById(R.id.textd);

}

score 0 · Answer 2 · answered Mar 23 '20 at 21:00

Just make this minor change:

    prefs= 
         getSharedPreferences("my_data",MODE_PRIVATE);
         String name=prefs.getString("MY_NAME","name");

Instead of

      SharedPreferences prefs= 
       getSharedPreferences("my_data",MODE_PRIVATE);
       String name = prefs.getString("MY_NAME","name");

You have already defined sharedpref object globally. You dont need to again create it.

I want to save with shared preference but the app crashes

2 Answers2