Create a banner with AdMob on Android using Java or Kotlin

Step 1: AdMob Configuration

1. Create an AdMob account: If you don’t have an AdMob account yet, go to AdMob and sign up.
2. Create an app and an ad:
   • After logging in to AdMob, create a new app and a new banner ad.
3. Get the ad unit ID:
   • Copy the ad unit ID you have created, as you will need it in your app’s code.

Step 2: Android Project Setup

1. Open your project in Android Studio:
   • Make sure you have Android Studio installed and open your project.
2. Add the AdMob dependency:
   • Open your build.gradle file (Module: app) and make sure you have the following dependency:

implementation 'com.google.android.gms:play-services-ads:22.5.0'

Also, add the application ID (I recommend saving it in your app’s strings):

   <meta-data
            android:name="com.google.android.gms.ads.APPLICATION_ID"
            android:value="@string/ads_app" />

Change the content of @string/ads_app to your application ID.

Sync the project:

• Sync your project so that dependencies are downloaded and installed.

Step 3: Implementing the Banner in Your Activity

1. Create an exportable banner:
   • Create a new file named banner.xml inside res > layout and now add this content:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:id="@+id/banner"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:layout_alignParentBottom="true"
    android:orientation="vertical">

    <com.google.android.gms.ads.AdView
        xmlns:ads="http://schemas.android.com/apk/res-auto"
        android:id="@+id/adview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        ads:adSize="BANNER"
        ads:adUnitId="your_ad_unit_id "/>

</LinearLayout>

In your_ad_unit_id you’ll need to add your AdMob ad unit id.

*I recommend you save the ad unit id in Strings so you can quickly change it in the future.

For that:

• Go to res > values > strings

• Add a new key, with your ad unit id.

 <string name="ads_banner" translatable="false">your_ad_unit_id</string>

• To use it you’ll have to put:

ads:adUnitId="@stringads_banner"

2. Add the banner to the View where you want to display it:

<include layout="@layout/banner"></include>

And that’s it:

Java code:

Open your Java file (MainActivity.java for example) and add the following code to load the banner:

import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;

public class MainActivity extends AppCompatActivity {

    private AdView adView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Find the AdView by its ID
        adView = findViewById(R.id.adView);

        // Create an ad request
        AdRequest adRequest = new AdRequest.Builder().build();

        // Load the ad into the AdView
        adView.loadAd(adRequest);
    }

    @Override
    protected void onDestroy() {
        // Release resources when the activity is destroyed
        if (adView != null) {
            adView.destroy();
        }
        super.onDestroy();
    }
}

Kotlin code:

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.google.android.gms.ads.AdRequest
import com.google.android.gms.ads.AdView

class MainActivity : AppCompatActivity() {

    private lateinit var adView: AdView

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Find the AdView by its ID
        adView = findViewById(R.id.adView)

        // Create an ad request
        val adRequest = AdRequest.Builder().build()

        // Load the ad into the AdView
        adView.loadAd(adRequest)
    }

    override fun onDestroy() {
        // Release resources when the activity is destroyed
        adView.destroy()
        super.onDestroy()
    }
}

Step 4: Permissions in the Manifest

Make sure you have internet access permission in your AndroidManifest.xml file:

<uses-permission android:name="android.permission.INTERNET" />

Step 5: Run the Application

That’s it! Now you should be able to run your application and see the AdMob banner at the top or bottom of your activity.

Please note that it may take some time for ads to appear after implementation due to AdMob’s settings and ad loading.

Extra: Test Code

I share the default test code with which it is recommended to run any ad you want to display in the development environment to avoid being penalized by Google AdMob:

<string name="ads_app" translatable="false">ca-app-pub-3940256099942544~3347511713</string>
<string name="ads_banner" translatable="false">ca-app-pub-3940256099942544/6300978111</string>