MainActivity.java

package com.okedroid.contohaplikasi;

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

public class MainActivity extends AppCompatActivity {
    /**
     * By Fathurrahman (okedroid.com)
     */

    EditText userName, passWord;
    SharedPreferences preferences;
    public static final String KEYPREF = "Key Preferences";
    public static final String KEYUSERNAME = "Key Username";
    public static final String KEYPASSWORD = "Key Password";
    //deklarasi editext ,sharedpreferences ,dan Key


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


        getSupportActionBar().setTitle("Contoh SharedPreferences");
        getSupportActionBar().setSubtitle("Belajar di okedroid.com");

        userName = (EditText) findViewById(R.id.userName);
        passWord = (EditText) findViewById(R.id.passWord);
        //instansiasi editext


        preferences = getSharedPreferences(KEYPREF, Context.MODE_PRIVATE);

        //instansiasi preferences

        if (preferences.contains(KEYUSERNAME) && (preferences.contains(KEYPASSWORD))) {
            userName.setText(preferences.getString(KEYUSERNAME, ""));
            passWord.setText(preferences.getString(KEYPASSWORD, ""));

        }
        //kondisi jika aplikasi di buka kembali ,maka akan menyimpan data dari sharedpreferences
        //berdasarkan Key
    }

    public void loginAkun(View view) {
        String user = userName.getText().toString();
        String pass = passWord.getText().toString();
        SharedPreferences.Editor editor = preferences.edit();
        editor.putString(KEYUSERNAME, user);
        editor.putString(KEYPASSWORD, pass);
        editor.apply();
        Toast.makeText(this, "UserName dan Password disimpan", Toast.LENGTH_SHORT).show();
        //menyimpan data user dan pass
        //dengan method appley


    }

    public void clearKolom(View view) {

        userName.setText("");
        passWord.setText("");

      //hanya bertugas mengkosongkan kolom, bukan menghapus data dari SharedPreferences
    }


}