Serverless Programming Cookbook

How to do it...

Let us do dependency injection with Guice, which is a lightweight framework suggested by AWS.

1. Add Maven dependency for Guice:

<dependency>    <groupId>com.google.inject</groupId>    <artifactId>guice</artifactId>    <version>4.2.0</version></dependency>

2. Create the Guice configuration class to bind interfaces to implementation:

public class ApplicationModule extends AbstractModule {    protected final void configure() {        bind(IAMService.class).to(IAMServiceImpl.class);    }}

3. Configure the handler class for using Guice:

public final class MyLambdaHandler implements RequestHandler<IAMOperationRequest, IAMOperationResponse> {    private static final Injector INJECTOR =            Guice.createInjector(new ApplicationModule());    private IAMService service ...