How to execute Async task repeatedly after fixed time intervals in Android?


This example demonstrates how do I execute AsyncTask repeatedly after fixed time intervals 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="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   tools:context=".MainActivity">
   <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:text="AsyncTask"
      android:textSize="24sp"
      android:textStyle="bold">
   </TextView>
</RelativeLayout>

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

import androidx.appcompat.app.AppCompatActivity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      RunTask();
   }
   private void RunTask() {
      MyToast myToast = new MyToast();
      myToast.execute();
   }
   private class MyToast extends AsyncTask<String, Void,String> {
      @Override
      protected String doInBackground(String... strings) {
         return null;
      }
      @Override
      protected void onPostExecute(String s) {
         final Handler handler = new Handler();
         handler.postDelayed(new Runnable() {
            @Override
            public void run() {
               handler.postDelayed(this, 5000);
               Toast.makeText(getApplicationContext(), "AsyncTask runs every 5 seconds", Toast.LENGTH_SHORT).show();
            }
         }, 3000);
      }
   }
}

Step 4 − Add the following code to androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://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 −

Click here to download the project code.

raja
Published on 11-Sep-2019 14:32:59
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