How to use SharedPrefernces in Android?

This example demonstrates how do I use shared preferences in android.

Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.

Step 2 − Add the following code to res/layout/activity_main.xml.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="https://schemas.android.com/apk/res/android"
   xmlns:tools="https://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   tools:context=".MainActivity">
   <EditText
      android:id="@+id/etName"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentTop="true"
      android:layout_centerHorizontal="true"
      android:ems="10"
      android:layout_marginTop="75dp"
      android:hint="Enter Name"/>
   <EditText
      android:id="@+id/etPassword"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_below="@id/etName"
      android:ems="10"
      android:layout_centerHorizontal="true"
      android:hint="Enter Password"/>
   <Button
      android:id="@+id/btnLogin"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="Login"
      android:layout_below="@id/etPassword"
      android:layout_alignStart="@id/etPassword"
      android:layout_marginTop="10dp" />
   <CheckBox
      android:id="@+id/checkBox"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_below="@id/btnLogin"
      android:layout_marginTop="10dp"
      android:text="Remember my credentials"
      android:layout_alignStart="@id/btnLogin"/>
</RelativeLayout>

Step 3 − Add the following code to src/MainActivity.java

import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity {
   SharedPreferences sharedPreferences;
   SharedPreferences.Editor editor;
   EditText name, password;
   Button button;
   CheckBox checkBox;
   String strName, strPassword, strCheckBox;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      name = findViewById(R.id.etName);
      password = findViewById(R.id.etPassword);
      button = findViewById(R.id.btnLogin);
      checkBox = findViewById(R.id.checkBox);
      sharedPreferences =PreferenceManager.getDefaultSharedPreferences(this);
      editor = sharedPreferences.edit();
      checkSharedPreference();
      button.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            if (checkBox.isChecked()) {
               editor.putString(getString(R.string.checkBox),"True");
               editor.commit();
               strName = name.getText().toString();
               editor.putString(getString(R.string.name), strName);
               editor.commit();
               strPassword = password.getText().toString();
               editor.putString(getString(R.string.password), strPassword);
               editor.commit();
            } else {
               editor.putString(getString(R.string.checkBox),"False");
               editor.commit();
               editor.putString(getString(R.string.name), "");
               editor.commit();
               editor.putString(getString(R.string.password), "");
               editor.commit();
            }
         }
      });
   }
   private void checkSharedPreference(){
      strCheckBox= sharedPreferences.getString(getString(R.string.checkBox), "False");
      strName = sharedPreferences.getString(getString(R.string.name), "");
      strPassword = sharedPreferences.getString(getString(R.string.password), "");
      name.setText(strName);
      password.setText(strPassword);
      if (strCheckBox.equals("True")) {
         checkBox.setChecked(true);
      } else {
         checkBox.setChecked(false);
      }
   }
}

Step 4 – Open res/values/stringd.xml and add the following code −

<resources>
   <string name="app_name">Sample</string>
   <string name="checkBox">Sample.checkbox</string>
   <string name="name">Sample.name</string>
   <string name="password">Sample.password</string>
</resources>

Step 4 - Add the following code to androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="https://schemas.android.com/apk/res/android"
   package="app.com.sample">
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      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>

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen –