how to save user login info in android device,

Main Activity xml

<?xml version="1.0" encoding="utf-8"?>

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="64dp"
        app:layout_constraintBottom_toTopOf="@+id/editText"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="32dp"
        android:layout_marginRight="32dp"
        android:layout_marginBottom="32dp"
        android:text="Save Note"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <EditText
        android:id="@+id/editText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="32dp"
        android:ems="10"
        android:hint="Enter Notes"
        android:inputType="textPersonName"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/button"
        app:layout_constraintHorizontal_bias="0.538"
        app:layout_constraintStart_toStartOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

Main Activity java

package guru.happylife.sharedashish;



import androidx.appcompat.app.AppCompatActivity;

import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    Button button;
    TextView textView;
    EditText editText;

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

        button = findViewById(R.id.button);
        textView = findViewById(R.id.textView);
        editText = findViewById(R.id.editText);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String msg = editText.getText().toString();

                SharedPreferences shrd = getSharedPreferences("demo", MODE_PRIVATE);
                SharedPreferences.Editor editor = shrd.edit();

                editor.putString("str1", msg);
                editor.putString("str2", "This is value 2 added by me");
                editor.putString("str3", "This is value 3 added by me");
                editor.apply();

                textView.setText(msg);

            }
        });

        // Get the value of shared preference back
        SharedPreferences getShared = getSharedPreferences("demo", MODE_PRIVATE);
        String value1 = getShared.getString("str1","Save a note and it will show up here");
        String value2 = getShared.getString("str2","Save a note and it will show up here");
        String value3 = getShared.getString("str3","Save a note and it will show up here");
        textView.setText(value1 + value2 + value3);


    }
}