MainActivity.java

package com.example.githubpush;

import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    EditText email,mobile;

    SharedPreferences sharedPreferences;
    SharedPreferences.Editor editor;

    Button retrieve;

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

        email = findViewById(R.id.email);
        mobile = findViewById(R.id.mobile);

        retrieve = findViewById(R.id.retrive);

        sharedPreferences = getSharedPreferences("my_sp",MODE_PRIVATE);
        editor = sharedPreferences.edit();


        findViewById(R.id.save).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                editor.putString("email",email.getText().toString()).apply();
                editor.putString("mobile",mobile.getText().toString()).apply();
                Toast.makeText(MainActivity.this, "saved successfully", Toast.LENGTH_SHORT).show();

                //editor.putString("email",email.getText().toString()).commit();
            }
        });

        retrieve.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                email.setText(sharedPreferences.getString("email",""));
                mobile.setText(sharedPreferences.getString("mobile",""));
            }
        });



    }

}