Custom endpoints for Spring Boot Actuator using annotations

In Spring Boot 1.x, in order to write a custom endpoint for Spring Boot Actuator, AbstractEndpoint had to be extended and its invoke method has been overridden with custom logic. Spring Boot Actuator is a production-ready feature for monitoring and managing a Spring Boot application using HTTP endpoints or JMX. Auditing metrics such as health could also be gathered using this feature. Finally, it had to be injected into the Spring Context as a Bean. This endpoint was technologically agnostic, in the sense that it could be invoked using JMX as well as with web requests.

If a custom behavior was required for a particular technology, such as JMX or the web, then AbstractEndpointMvcAdapter or EndpointMBean had to be extended respectively and had to be injected as a Spring Bean. This is cumbersome, and Spring Boot 2.0 has introduced technology-specific annotations such as @Endpoint, @WebEndpoint, and @JmxEndpoint; technology-independent operation annotations such as @ReadOperation, @WriteOperation, and @DeleteOperation; and technology-specific extension annotations such as  @EndpointWebExtension and @EndpointJmxExtension, to ease this process.