shared preference android app studio source code

main_activity.java

==================

package com.sam.web.sharedpreference;

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 implements View.OnClickListener{

    private TextView detailsTextView;

    private EditText usernameEditText,passwordEditText;

    private Button saveButton,loadButton;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        detailsTextView=(TextView) findViewById(R.id.detailsTextViewId);

        usernameEditText=(EditText) findViewById(R.id.usernameEditTextID);

        passwordEditText=(EditText) findViewById(R.id.passwordEditTextID);

        saveButton=(Button) findViewById(R.id.saveButtonId);

        loadButton=(Button) findViewById(R.id.loadButtonId);

        saveButton.setOnClickListener(this);

        loadButton.setOnClickListener(this);

    }

    @Override

    public void onClick(View view) {

        if (view.getId()==R.id.saveButtonId){

            String username=usernameEditText.getText().toString();

            String password=passwordEditText.getText().toString();

            //if username null and password null then toast show

            if(username.equals("")&& password.equals(""))

            {

                Toast.makeText(getApplicationContext(),"please enter some data",Toast.LENGTH_SHORT).show();

            }

            else {

                //writing data

                SharedPreferences sharedPreferences=getSharedPreferences("userDetails", Context.MODE_PRIVATE);

                SharedPreferences.Editor editor=sharedPreferences.edit();

                editor.putString("usernameKey","username");

                editor.putString("passwordKey","password");

                editor.commit();

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

            }

        }

        else if (view.getId()==R.id.loadButtonId){

            // to read data

            SharedPreferences sharedPreferences=getSharedPreferences("userDetails", Context.MODE_PRIVATE);

            if (sharedPreferences.contains("usernameKey") && sharedPreferences.contains("passwordKey"))

            {

                String username=sharedPreferences.getString("usernameKey","Data not found");

                String password=sharedPreferences.getString("passwordKey","Data not found");

                detailsTextView.setText(username+" "+password);

            }

        }

    }

}

==========================================================================================================

Activity_main.xml

=================

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

<LinearLayout 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"

    android:orientation="vertical"

    tools:context="com.sam.web.sharedpreference.MainActivity">

 <EditText

     android:textStyle="bold"

     android:textSize="20sp"

     android:textAlignment="center"

     android:hint="Edit your user name"

     android:id="@+id/usernameEditTextID"

     android:layout_marginTop="20dp"

     android:layout_width="match_parent"

     android:layout_height="wrap_content" />

 <EditText

     android:inputType="textPassword"

     android:textStyle="bold"

     android:textSize="20sp"

     android:textAlignment="center"

     android:hint="Edit your user password"

     android:id="@+id/passwordEditTextID"

     android:layout_marginTop="20dp"

     android:layout_width="match_parent"

     android:layout_height="wrap_content" />

    <LinearLayout

        android:gravity="center"

        android:layout_width="match_parent"

        android:layout_height="wrap_content">

        <Button

            android:layout_marginRight="10dp"

            style="@style/Widget.AppCompat.Button.Colored"

            android:textStyle="bold"

            android:textSize="17sp"

            android:text="save"

            android:id="@+id/saveButtonId"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content" />

        <Button

            style="@style/Widget.AppCompat.Button.Colored"

            android:textStyle="bold"

            android:textSize="17sp"

            android:text="load"

            android:id="@+id/loadButtonId"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content" />

    </LinearLayout>

    <TextView

        android:layout_marginTop="20dp"

        android:textAlignment="center"

        android:textStyle="bold"

        android:textSize="20sp"

        android:id="@+id/detailsTextViewId"

        android:layout_width="match_parent"

        android:layout_height="wrap_content" />

</LinearLayout>