api-keys-local-props.md

Hiding API keys in local.properties

1. Make sure your build directory is gitignored. It should be, by default, in a new Android Studio project -- you can double check by making sure that your .gitignore file contains the line:

/build

2. In your project root directory, add the API key to local.properties file like this:

apiKey="hgjfkhg5764317698315768549027nfdsngadf"

Where hgjfkhg5764317698315768549027nfdsngadf would be your API key.

3. Add the following lines at the root level of your app-level build.gradle file:

def localPropertiesFile = rootProject.file("local.properties")
def localProperties = new Properties()
localProperties.load(new FileInputStream(localPropertiesFile))

4. Pull the API into your project as a build config value by adding the following line to your app level build.gradle file in the android { defaultConfig { } } block:

def localPropertiesFile = rootProject.file("local.properties")
def localProperties = new Properties()
localProperties.load(new FileInputStream(localPropertiesFile))


android {
    // ...
    
    defaultConfig {
        // ...
        buildConfigField "String", "API_KEY", localProperties['apiKey']

    }
    
    // ...
    
}

5. Sync Gradle and build the project. You can now access the key in your Java code with BuildConfig.API_KEY, for example:

String myApiKey = BuildConfig.API_KEY;

6. You can add as many secret values as you'd like to your local.properties by following these steps. Give each one a unique reference, i.e. myApiKey2, BuildConfig.API_KEY_2