Previously, we learn about Android Persistence with Internal Storage. Now we see how to use Android Persistence with Shared Preferences.

Android provides many ways of storing data of an application. One of this way is called Shared Preferences. Shared Preferences allow you to save and retrieve data in the form of key, value pair.

In order to use shared preferences, you have to call a method getSharedPreferences () that returns a SharedPreference instance pointing to the file that contains the values of preferences.

The SharedPreferences class provides a general framework that allows you to save and retrieve persistent key-value pairs of primitive data types. You can use SharedPreferences to save any primitive data: booleans, floats, ints, longs, and strings.  

1.      Create an android project.

2.      Add controls in activity_main.xml

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

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    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=".MainActivity" >

 

    <LinearLayout

          android:layout_width="fill_parent"

          android:layout_height="wrap_content"

          android:layout_marginTop="30sp"

          android:orientation="horizontal"   >

 

        <TextView

              android:id="@+id/tvName"

              android:layout_width="0dp"

              android:layout_height="wrap_content"

              android:layout_weight=".40"

              android:text="Employee Name-: "   />

 

        <EditText

              android:id="@+id/editName"

              android:layout_width="0dp"

              android:layout_height="wrap_content"

              android:layout_weight=".60"

              android:maxLength="20"   />

    </LinearLayout>

 

    <LinearLayout

          android:layout_width="fill_parent"

          android:layout_height="wrap_content"

          android:layout_marginTop="30sp"

          android:orientation="horizontal"   >

 

        <TextView

              android:id="@+id/tvSallary"

              android:layout_width="0dp"

              android:layout_height="wrap_content"

              android:layout_weight=".40"

              android:text="Sallary-: "   />

 

        <EditText

              android:id="@+id/editSallary"

              android:layout_width="0dp"

              android:layout_height="wrap_content"

              android:layout_weight=".60"

              android:digits="1234567890-."

              android:inputType="number"

              android:maxLength="15"   />

    </LinearLayout>

 

    <LinearLayout

          android:layout_width="fill_parent"

          android:layout_height="wrap_content"

          android:layout_gravity="center"

          android:layout_marginTop="30sp"

          android:gravity="center"   >

 

        <Button

              android:id="@+id/btnSave"

              android:layout_width="wrap_content"

              android:layout_height="wrap_content"

              android:text="  Save    " />

    </LinearLayout>

 

    <Button

          android:id="@+id/btnGetData"

          android:layout_width="wrap_content"

          android:layout_height="wrap_content"

          android:layout_gravity="center"

          android:layout_marginTop="10sp"

          android:text="Retrieve Data"   />

 

</LinearLayout>

 3.      And paste following code in MainActivity.class 

package  com.example.androidpersistencesample;
 
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import  android.content.SharedPreferences;
import  android.content.SharedPreferences.Editor;
import android.view.View;
import  android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
 
public class MainActivity extends  Activity {
            Button  btnSave, btnGetData;
            EditText  etname;
            EditText  etSallary;
 
// Define key Name
            public  static final String MyPREFERENCES = "Employee";
            public  static final String EName = "EmployeeName";
            public  static final String ESallary = "EmployeeSallary";
 
            // Shared  Preferences allow you to save and retrieve data in the form of
            //  key,value pair.
            SharedPreferences  sharedpreferences;
 
            @Override
            protected  void onCreate(Bundle savedInstanceState) {
                        super.onCreate(savedInstanceState);
                        setContentView(R.layout.activity_main);
                        btnSave = (Button) findViewById(R.id.btnSave);
                        btnGetData = (Button) findViewById(R.id.btnGetData);
                        etname = (EditText) findViewById(R.id.editName);
                        etSallary = (EditText) findViewById(R.id.editSallary);
 
                        // This method retrieve data from file and fill value in edit text
                        readDatafromFile();
 
                        btnSave.setOnClickListener(new OnClickListener() {
 
                                    @Override
                                    public void onClick(View v) {
 
                                                // Interface used for modifying values in a SharedPreferences
                                                Editor editor = sharedpreferences.edit();
 
                                                // put key and value in Editor
                                                editor.putString(EName, etname.getText().toString());
                                                editor.putString(ESallary, etSallary.getText().toString());
 
                                                // after add data clear edittext
                                                etname.setText("");
                                                etSallary.setText("");
 
                                                // Commit your preferences changes back from this Editor to the
                                                // SharedPreferences object it is editing.
                                                editor.commit();
 
                                                Toast.makeText(getApplicationContext(), "Data saved",
                                                                        Toast.LENGTH_SHORT).show();
                                    }
                        });
                        btnGetData.setOnClickListener(new OnClickListener() {
 
                                    @Override
                                    public void onClick(View v) {
 
                                                readDatafromFile();
                                    }
                        });
            }
 
            public void readDatafromFile() {
 
                        // getSharedPreferences use if you need multiple preferences files
                        // identified by name, which you specify with the first parameter.
                        sharedpreferences = getSharedPreferences(MyPREFERENCES,
                                                Context.MODE_PRIVATE);
 
                        // set value in edit text
                        if (sharedpreferences.contains(EName)) {
 
                                    etname.setText(sharedpreferences.getString(EName, ""));
 
                        }
                        if (sharedpreferences.contains(ESallary)) {
                                    etSallary.setText(sharedpreferences.getString(ESallary, ""));
 
                        }
            }
}

And run your application

Exit your activity and reopen this application