How to detect application heap size in android?

This example demonstrates how do I detect application heap size 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"?>
<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:gravity="center"
   android:padding="8dp"
   tools:context=".MainActivity">
   <Button
      android:onClick="HeapSize"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="Detect Heap Size"/>
   <TextView
      android:textSize="24sp"
      android:textStyle="bold"
      android:id="@+id/textView"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content" />
</LinearLayout>

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

import androidx.appcompat.app.AppCompatActivity;
import android.app.ActivityManager;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import java.util.Objects;
public class MainActivity extends AppCompatActivity {
   TextView textView;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      textView = findViewById(R.id.textView);
   }
   public void HeapSize(View view) {
      ActivityManager activityManager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
      int memoryClass = Objects.requireNonNull(activityManager).getMemoryClass();
      textView.setText("Heap Size: " + memoryClass);
   }
}

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 the android studio, open one of your project's activity files and click the Run icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen −