How to refresh Activity when IntentService is finished in android?

Before getting into the example, we should know what Intent service is in android. Intent Service is going to do background operation asynchronously. When user call startService() from activity, it doesn’t create an instance for each request and it going to stop service after done some action in service class or else we need to stop service using stopSelf().
This example demonstrates How to refresh Activity when IntentService is finished.
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"?>
<android.support.constraint.ConstraintLayout 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"
   tools:context = ".MainActivity">
   <TextView
      android:id = "@+id/text"
      android:layout_width = "wrap_content"
      android:layout_height = "wrap_content"
      android:text = "Start Service"
      android:textSize = "25sp"
      app:layout_constraintBottom_toBottomOf = "parent"
      app:layout_constraintLeft_toLeftOf = "parent"
      app:layout_constraintRight_toRightOf = "parent"
      app:layout_constraintTop_toTopOf = "parent" />
</android.support.constraint.ConstraintLayout>
In the above code, we have taken text view, when the user gets the data from intent service it will update.
Step 3 − Add the following code to src/MainActivity.java
package com.example.andy.myapplication;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.v4.content.LocalBroadcastManager;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
   TextView text;
   BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
      @Override
      public void onReceive(Context context, Intent intent) {
         String someValue = intent.getStringExtra("someName");
         text.setText(someValue);
      }
   };
   @Override
   protected void onStart() {
      super.onStart();
      IntentFilter intentFilter = new IntentFilter();
      intentFilter.addAction("com.example.andy.myapplication");
      LocalBroadcastManager.getInstance(this).registerReceiver(broadcastReceiver, intentFilter);
   }
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      text = findViewById(R.id.text);
      text.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            startService(new Intent(MainActivity.this, service.class));
         }
      });
   }
   @Override
   protected void onStop() {
      super.onStop();
      LocalBroadcastManager.getInstance(this).unregisterReceiver(broadcastReceiver);
   }
}
Create a class called service.class file and add the following code –
package com.example.andy.myapplication;

import android.app.IntentService;
import android.content.Intent;
import android.os.IBinder;
import android.support.v4.content.LocalBroadcastManager;

public class service extends IntentService {
   public static volatile boolean shouldStop = false;
   public service() {
      super(service.class.getSimpleName());
   }
   @Override
   public IBinder onBind(Intent intent) {
      return null;
   }
   @Override
   protected void onHandleIntent(Intent intent) {
      Intent intent1 = new Intent("com.example.andy.myapplication");
      intent1.putExtra("someName", "Tutorialspoint.com");
      LocalBroadcastManager.getInstance(this).sendBroadcast(intent1);
      if(shouldStop){
         stopSelf();
         return;
      }
   }
}
Step 4 − Add the following code to manifest.xml
<?xml version = "1.0" encoding = "utf-8"?>
<manifest xmlns:android = "http://schemas.android.com/apk/res/android"
   package = "com.example.andy.myapplication">
   <uses-permission android:name = "android.permission.WAKE_LOCK"/>
   <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>
      <service android:name = ".service"/>
   </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 –
In the above result, it has shown a default screen of an application. When user click on “Start Service” it will start service and update the textview as shown below-
Click here to download the project code