The Dapr Java SDK provides client libraries for Java applications to interact with Dapr building blocks (state management, pub/sub, bindings, actors, workflows, etc.). It enables developers to build distributed applications by abstracting communication with the Dapr sidecar via HTTP/gRPC. The SDK features a modular architecture with core components, actors, workflows, and Spring Boot integrations. Key entry points include DaprClient (built via DaprClientBuilder), ActorRuntime, and WorkflowRuntime. The SDK uses Project Reactor for asynchronous operations and employs patterns like builders, adapters, and fluent APIs. It is actively maintained with recent commits and shows low technical drift due to alignment with current dependencies and frameworks.