Create android application to Understand Android Share Preference. - code, android programming

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

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.example.dharmik.p11">



    <application

        android:allowBackup="true"

        android:icon="@mipmap/ic_launcher"

        android:label="@string/app_name"

        android:supportsRtl="true"

        android:theme="@style/AppTheme">

        <activity android:name=".MainActivity">

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />



                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

    </application>



</manifest>

package com.example.dharmik.p11;



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 username,password;

    Button insert,show,delete;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        username=(EditText)findViewById(R.id.et1);

        password=(EditText)findViewById(R.id.et2);

        insert=(Button)findViewById(R.id.bt1);

        show=(Button)findViewById(R.id.bt2);

        delete=(Button)findViewById(R.id.bt3);

        final SharedPreferences sp=getApplicationContext().getSharedPreferences("MyPrefs",MODE_PRIVATE);

        final SharedPreferences.Editor et=sp.edit();

        insert.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                Toast.makeText(getApplicationContext(),"all previous data is being deleted",Toast.LENGTH_SHORT).show();

                et.clear();

                et.commit();

                et.putString("username",username.getText().toString());

                et.putString("password",password.getText().toString());

                et.commit();

                username.setText(null);

                password.setText(null);

                Toast.makeText(getApplicationContext(),"data stored successfully",Toast.LENGTH_SHORT).show();

            }

        });



        show.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                String un=sp.getString("username",null);

                String pass=sp.getString("password",null);

                username.setText(un);

                password.setText(pass);

                Toast.makeText(getApplicationContext(),"data fetched successfully",Toast.LENGTH_SHORT).show();

                if (un==null || pass==null)

                    Toast.makeText(getApplicationContext(),"no data found",Toast.LENGTH_SHORT).show();

            }

        });



        delete.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                et.clear();

                et.commit();

                username.setText(null);

                password.setText(null);

                Toast.makeText(getApplicationContext(),"all data deleted successfully",Toast.LENGTH_SHORT).show();

            }

        });

    }

}

//activity_main.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:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context="com.example.dharmik.p11.MainActivity">



    <TextView

        android:text="@string/username"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_marginLeft="15dp"

        android:layout_marginStart="15dp"

        android:layout_marginTop="91dp"

        android:id="@+id/tv1"

        android:layout_alignParentTop="true"

        android:layout_alignParentLeft="true"

        android:layout_alignParentStart="true" />



    <TextView

        android:text="@string/password"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_marginTop="69dp"

        android:id="@+id/tv2"

        android:layout_below="@+id/tv1"

        android:layout_alignLeft="@+id/tv1"

        android:layout_alignStart="@+id/tv1" />



    <Button

        android:text="@string/insert"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_marginTop="69dp"

        android:id="@+id/bt1"

        android:layout_below="@+id/et2"

        android:layout_centerHorizontal="true" />



    <Button

        android:text="@string/show"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_marginTop="31dp"

        android:id="@+id/bt2"

        android:layout_below="@+id/bt1"

        android:layout_centerHorizontal="true" />



    <Button

        android:text="@string/delete"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/bt3"

        android:layout_below="@+id/bt2"

        android:layout_centerHorizontal="true"

        android:layout_marginTop="20dp" />



    <EditText

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:inputType="textPersonName"

        android:ems="10"

        android:id="@+id/et1"

        android:layout_alignBaseline="@+id/tv1"

        android:layout_alignBottom="@+id/tv1"

        android:layout_alignLeft="@+id/bt2"

        android:layout_alignStart="@+id/bt2" />



    <EditText

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:inputType="text"

        android:ems="10"

        android:id="@+id/et2"

        android:layout_alignBaseline="@+id/tv2"

        android:layout_alignBottom="@+id/tv2"

        android:layout_alignLeft="@+id/et1"

        android:layout_alignStart="@+id/et1" />

</RelativeLayout>

<resources>

    <string name="app_name">p11</string>

    <string name="username">username</string>

    <string name="password">password</string>

    <string name="insert">insert</string>

    <string name="show">show data</string>

    <string name="delete">delete</string>

</resources>

OUTPUT:-