Shared Preference Example in Android

MainActivity.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorPrimaryDark"
    tools:context="com.example.bhaumik.sharedpreferences.MainActivity">

  <LinearLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:orientation="vertical"
      android:id="@+id/layouts">
      <EditText
          android:id="@+id/et_username"
          android:layout_width="300dp"
          android:layout_height="wrap_content"
          android:hint="Enter UserName"
          android:padding="10dp"
          android:layout_gravity="center_horizontal"
          android:layout_marginTop="30dp"
          android:background="#FFF"/>
      <EditText
          android:id="@+id/et_password"
          android:layout_width="300dp"
          android:layout_height="wrap_content"
          android:hint="Enter Password"
          android:padding="10dp"
          android:layout_gravity="center_horizontal"
          android:layout_marginTop="30dp"
          android:background="#FFF"/>
  </LinearLayout>
    <Button
        android:id="@+id/btn_save"
        android:layout_width="120dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:textAllCaps="false"
        android:layout_marginLeft="30dp"
        android:text="Save It"
        android:layout_below="@+id/layouts"
        android:textSize="17dp"/>

    <Button
        android:id="@+id/btn_display"
        android:layout_width="120dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:textAllCaps="false"
        android:layout_marginLeft="200dp"
        android:text="Display Info"
        android:layout_below="@+id/layouts"
        android:textSize="17dp"/>

    <TextView
        android:id="@+id/tv_show"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/btn_display"
        android:layout_marginTop="20dp"
        android:textSize="20dp"
        android:textColor="#FFF"/>
</RelativeLayout>

MainActivity.java

package com.example.bhaumik.sharedpreferences;


import android.content.Context;
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.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    EditText username,password;
    Button save,display;
    TextView show;

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

        username = (EditText) findViewById(R.id.et_username);
        password = (EditText) findViewById(R.id.et_password);
        save = (Button) findViewById(R.id.btn_save);
        display = (Button) findViewById(R.id.btn_display);
        show = (TextView) findViewById(R.id.tv_show);

        save.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SharedPreferences preferences = getSharedPreferences("userinfo", Context.MODE_PRIVATE);
                SharedPreferences.Editor editor = preferences.edit();
                editor.putString("username",username.getText().toString());
                editor.putString("password",password.getText().toString());
                editor.apply();

                Toast.makeText(MainActivity.this,"User Saved...",Toast.LENGTH_SHORT).show();

            }
        });

        display.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                SharedPreferences preferences = getSharedPreferences("userinfo", Context.MODE_PRIVATE);


                String names = preferences.getString("username","");
                String pwd = preferences.getString("password","");

                show.setText("UserName :-> " + names + "     " + " Password :-> " + pwd);

            }
        });
    }
}