Android SDK reference
Read time: 2 minutes
Last edited: May 20, 2022
Overview
This topic documents how to get started with the Android SDK, and links to reference information on all of the supported features.
LaunchDarkly's SDKs are open source. In addition to this reference guide, we provide source, API reference documentation, and a sample application:
Resource | Location |
---|---|
SDK API documentation | SDK API docs |
GitHub repository | android-client-sdk |
Sample application | hello-android |
Published module | Maven |
The LaunchDarkly Android SDK is compatible with Android SDK versions 21 and higher (Android 5.0, Lollipop).
Getting started
After you complete the Getting started process, follow these instructions to start using the LaunchDarkly SDK in your Android application.
First, declare a dependency on the LaunchDarkly Android SDK:
implementation 'com.launchdarkly:launchdarkly-android-client-sdk:3.1.1'
The SDK uses AndroidX from Jetpack. If your project does not use AndroidX, read Android's migration guide.
If you use ProGuard or R8, the aar
artifact should automatically include the configuration for the Android SDK. If this is not the case for your build, include the Proguard configuration lines from consumer-proguard-rules.pro into your proguard file.
Next, import the LaunchDarkly client in your application code:
import com.launchdarkly.sdk.*;import com.launchdarkly.sdk.android.*;
After you install the SDK, create a single, shared instance of LDClient
. To create a client instance, you need your environment's mobile key. This authorizes your application to connect to a particular environment within LaunchDarkly. Your mobile key is available in the Projects tab of your Account settings page. Mobile keys are not secret and you can expose them in your client-side code without risk. Never embed a server-side SDK key into a client-side application.
It's important to make LDClient
a singleton. The client instance maintains internal state that allows LaunchDarkly to serve feature flags without making any remote requests. Do not instantiate a new client with every request.
The following example shows the simplest way to create the client. It will block for up to five seconds until the latest feature flags are retrieved from LaunchDarkly.
Here is how to create the client:
LDConfig ldConfig = new LDConfig.Builder().mobileKey("YOUR_MOBILE_KEY").build();LDUser user = new LDUser.Builder("user key").email("fake@example.com").build();LDClient client = LDClient.init(this.getApplication(), ldConfig, user, 5);
However, calling blocking code from the main thread in an Android app is not a best practice. The preferred method allows you to use the client immediately. The app stores flags from the previous launch on the device and retrieves them for immediate use. The client still connects in the background and continually updates itself with the latest flags.
You must make feature flags available to mobile SDKs before the SDK can evaluate those flags. If an SDK tries to evaluate a feature flag that is not available, the user will receive the default value for that flag.
To make a flag available to this SDK, check the SDKs using Mobile key checkbox during flag creation, or on the flag's Settings tab. To make all of a project's flags available to this SDK by default, check the SDKs using Mobile key checkbox in your project Settings.
Here is the preferred method:
LDClient client = LDClient.init(this.getApplication(), ldConfig, user, 0);
You can use client
to check which variation a particular user will receive for a feature flag.
Here's how:
boolean showFeature = client.boolVariation(flagKey, true);if (showFeature) {// Application code to show the feature}else {// The code to run if the feature is off}
Shutting down
Shut down the client when your application terminates. To learn more, read Shutting down.
Data collection
To learn more about data collection within this SDK and implications on submissions to the Apple App Store, read the Apple App Store data collection policy.
Supported features
This SDK supports the following features:
- Aliasing users
- Configuration
- Evaluating flags
- Flag evaluation reasons
- Flushing events
- Getting all flags
- Identifying and changing users
- Logging configuration
- Monitoring SDK status
- Multiple environments
- Offline mode
- Relay Proxy configuration
- Sending custom events
- Shutting down
- Subscribing to flag changes
- User configuration