The ASK SDK requires intent handlers for each of the expected intents. We will create intent handlers for our application-specific intent (for example, a self-intro intent), the launch intent—as well as help, stop, and cancel intents for the inbuilt intents—a fallback intent, and a session end request intent. We will then create a parent lambda handler class that registers all these intent handlers.

Let's start by defining the dependency of ASK SDK for Java in the POM file, as follows:

<dependency>
    <groupId>com.amazon.alexa</groupId>
    <artifactId>ask-sdk</artifactId>
    <version>${ask.sdk.version}</version>
</dependency>

The POM file also has dependencies for aws-lambda-java-core. The ask.sdk.version property is defined along with other properties in the parent project, POM serverless-cookbook-parent-aws-java:

<ask.sdk.version>2.11.2</ask.sdk.version>

We can create the Java Lambda project with the following package structure:

The SelfIntroIntentHandler class defines the speech text that does the introduction, as follows: 

public class SelfIntroIntentHandler implements RequestHandler {

    @Override
    public final boolean canHandle(final HandlerInput input) {
        return input.matches(Predicates.intentName("SelfIntroIntent"));
    }

    @Override
    public final Optional<Response> handle(final HandlerInput input) {
        String speechText = "Hello, this is Alexa saying intro for Heartin Kanikathottu. "
                + "Heartin is a senior software engineer and blogger with around 11 years of IT experience. "
                + "He likes to share his technical knowledge through his blogs such as CloudMaterials.com "
                + "and Java J EE dot com. "
                + "He also likes to mentor juniors and take sessions at meetups and conferences.";

        return input.getResponseBuilder()
                .withSpeech(speechText)
                .withSimpleCard("SelfIntro", speechText)
                .build();
    }

}

The LaunchRequestHandler class defines the speech text for the app launch, as follows:

public class LaunchRequestHandler implements RequestHandler {

    @Override
    public final boolean canHandle(final HandlerInput input) {
        return input.matches(Predicates.requestType(LaunchRequest.class));
    }

    @Override
    public final Optional<Response> handle(final HandlerInput input) {
        String speechText = "Welcome to the Self Intro Alexa Skill for Heartin, you may say 'please say intro'";
        return input.getResponseBuilder()
                .withSpeech(speechText)
                .withSimpleCard("SelfIntro", speechText)
                .withReprompt(speechText)
                .build();
    }
}

The HelpIntentHandler class defines the speech text for the inbuilt intent AMAZON.HelpIntent, as follows:

public class HelpIntentHandler implements RequestHandler {

    @Override
    public final boolean canHandle(final HandlerInput input) {
        return input.matches(intentName("AMAZON.HelpIntent"));
    }

    @Override
    public final Optional<Response> handle(final HandlerInput input) {
        String speechText = "You you may say 'please say intro'!";
        return input.getResponseBuilder()
                .withSpeech(speechText)
                .withSimpleCard("SelfIntro", speechText)
                .withReprompt(speechText)
                .build();
    }
}

The CancelandStopIntentHandler class defines the speech text for the for the inbuilt intents AMAZON.StopIntent and AMAZON.CancelIntent:

public class CancelandStopIntentHandler implements RequestHandler {

    @Override
    public final boolean canHandle(final HandlerInput input) {
        return input.matches(intentName("AMAZON.StopIntent").or(intentName("AMAZON.CancelIntent")));
    }

    @Override
    public final Optional<Response> handle(final HandlerInput input) {
        return input.getResponseBuilder()
                .withSpeech("Goodbye buddy")
                .withSimpleCard("SelfIntro", "Goodbye")
                .build();
    }

}

The FallbackIntentHandler class defines the speech text for the fallbacks when no intents match, as follows:

public class FallbackIntentHandler implements RequestHandler {

    @Override
    public final boolean canHandle(final HandlerInput input) {
        return input.matches(intentName("AMAZON.FallbackIntent"));
    }

    @Override
    public final Optional<Response> handle(final HandlerInput input) {
        String speechText = "Sorry buddy, I don't know that. You can say try saying help!";
        return input.getResponseBuilder()
                .withSpeech(speechText)
                .withSimpleCard("SelfIntro", speechText)
                .withReprompt(speechText)
                .build();
    }

}

We will also define a SessionEndedRequestHandler class for handling session termination requests, as shown in the following code:

public class SessionEndedRequestHandler implements RequestHandler {

    @Override
    public final boolean canHandle(final HandlerInput input) {
        return input.matches(requestType(SessionEndedRequest.class));
    }

    @Override
    public final Optional<Response> handle(final HandlerInput input) {
        //any cleanup logic goes here
        return input.getResponseBuilder().build();
    }

}

Finally, we will create the Lambda handler class that extends SkillStreamHandler, as follows:

public class SelfIntroStreamHandler extends SkillStreamHandler {

    private static Skill skill = Skills.standard()
            .addRequestHandlers(
                    new CancelandStopIntentHandler(),
                    new SelfIntroIntentHandler(),
                    new HelpIntentHandler(),
                    new LaunchRequestHandler(),
                    new SessionEndedRequestHandler())
            .build();

    public SelfIntroStreamHandler() {
        super(skill);
    }

}