aws-lambda-java-integration

AWS Lambda Java Integration

Patterns for creating high-performance AWS Lambda functions in Java with optimized cold starts.

Overview

This skill provides complete patterns for AWS Lambda Java development, covering two main approaches:

1. Micronaut Framework - Full-featured framework with AOT compilation, dependency injection, and cold start < 1s
2. Raw Java - Minimal overhead approach with cold start < 500ms

Both approaches support API Gateway and ALB integration with production-ready configurations.

When to Use

• Deploying Java functions to AWS Lambda
• Optimizing cold starts below 1 second
• Choosing between Micronaut and Raw Java approaches
• Configuring API Gateway or ALB integration
• Setting up CI/CD pipelines for Java Lambda

Instructions

1. Choose Your Approach

Approach	Cold Start	Best For	Complexity
Micronaut	< 1s	Complex apps, DI needed, enterprise	Medium
Raw Java	< 500ms	Simple handlers, minimal overhead	Low

Validate: Confirm the approach fits your use case before proceeding.

2. Project Structure

my-lambda-function/
├── build.gradle (or pom.xml)
├── src/main/java/com/example/Handler.java
└── serverless.yml (or template.yaml)

Validate: Verify project structure matches the template.

3. Implementation Examples

Micronaut Handler

@FunctionBean("my-function")
public class MyFunction implements Function<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {

    private final MyService service;

    public MyFunction(MyService service) {
        this.service = service;
    }

    @Override
    public APIGatewayProxyResponseEvent apply(APIGatewayProxyRequestEvent request) {
        // Process request
        return new APIGatewayProxyResponseEvent()
            .withStatusCode(200)
            .withBody("{\"message\": \"Success\"}");
    }
}

Raw Java Handler

public class MyHandler implements RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {

    private static final MyService service = new MyService();

    @Override
    public APIGatewayProxyResponseEvent handleRequest(APIGatewayProxyRequestEvent request, Context context) {
        return new APIGatewayProxyResponseEvent()
            .withStatusCode(200)
            .withBody("{\"message\": \"Success\"}");
    }
}