aws-sdk-java-v2-core

# AWS SDK for Java 2.x Core Patterns ## Overview Use this skill to set up AWS SDK for Java 2.x clients with production-safe defaults. It focuses on the decisions that matter most: - how credentials and region are resolved - how to configure sync and async HTTP clients - how to apply timeouts, retries, lifecycle management, and tests Keep `SKILL.md` focused on setup and delivery flow. Use the `references/` files for deeper API details and expanded examples. ## When to Use - Creating or hardening AWS SDK for Java 2.x service clients - Wiring Spring Boot beans for AWS integration - Debugging auth, region, or credential issues - Choosing between sync (`S3Client`, `DynamoDbClient`) and async (`S3AsyncClient`, `SqsAsyncClient`) clients ## Instructions ### 1. Select the service client type - Sync clients (`S3Client`, `DynamoDbClient`) for request/response flows - Async clients (`S3AsyncClient`, `SqsAsyncClient`) for concurrency, streaming, or backpressure - Reuse one client per service and configuration profile ### 2. Configure credential and region resolution Use `DefaultCredentialsProvider` with environment-aware defaults: - local dev: shared AWS config, SSO, or environment variables - CI/CD: web identity or injected environment variables - AWS runtime: ECS task roles, EKS IRSA, or EC2 instance profiles Override only for multi-account access, test isolation, or profile switching. **Verify**: Call `StsClient.getCallerIdentity()` at startup to confirm credentials resolv...