Manage Google Maps API Key with Gradle in Android Studio

In Android Studio (checked with version 0.8.11) you can add Google Maps Activity (New->Google->Google Maps Activity) to your project and Android studio will generate necessary files for you, you only have to insert your keys. There are also instructions generated. Look for google_maps_api.xml files in your debug/res/values/ and release/res/values folders.

You can achieve this with manifest placeholder feature: http://tools.android.com/tech-docs/new-build-system/user-guide/manifest-merger#TOC-Placeholder-support

in build.gradle file:

buildTypes {
    debug {
        manifestPlaceholders = [ google_map_key:"your_dev_key"]
    }
    release {
        manifestPlaceholders = [ google_map_key:"prod_key"]
    }
}

and then in manifest:

<meta-data
    android:name="com.google.android.maps.v2.API_KEY"
    android:value="${google_map_key}"/>

That's exact thing for different keys for different flavors and this is cleaner solution than using string resources.

P.S. On the other hand I would better consider getting api keys from backend and do not hardcode them on the client. This is more secure and more flexible approach.

Since you are using gradle you can do the following:

build.gradle

android {
  .. .. ...
    buildTypes {
       debug {
          resValue "string", "google_maps_api_key", "[YOUR DEV KEY]"
       }
       release {
           resValue "string", "google_maps_api_key", "[YOUR PROD KEY]"
       }
    }
  }

And in your AndroidManifest.xml

<meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="@string/google_maps_api_key"/>

This way you only have one AndroidManifest.xml and you set value based on your build type. Hope this helps.