Spring Boot Actuator - how to add custom logic to /shutdown endpoint

Question

In my project I started using Spring Boot Actuator. I use /shutdown endpoint to gracefully stop the embedded Tomcat (this works well), but I also need to do some custom logic during shutdown. Is there any way, how to do it?

Answer 1

I can think of two ways to perform some logic before shutting down the application:

1. Registering a Filter, it's a web application after all.
2. Intercepting the invoke method using the @Before advice

Servlet Filter

---

Since /shutdown is a Servlet endpoint, you can register a Filter to run before the /shutdown endpoint gets called:

public class ShutdownFilter extends OncePerRequestFilter {
    @Override
    protected void doFilterInternal(HttpServletRequest request,
                                    HttpServletResponse response,
                                    FilterChain filterChain) 
                                    throws ServletException, IOException {
        // Put your logic here
        filterChain.doFilter(request, response);
    }
}

Also don't forget to register it:

@Bean
@ConditionalOnProperty(value = "endpoints.shutdown.enabled", havingValue = "true")
public FilterRegistrationBean filterRegistrationBean() {
    FilterRegistrationBean registrationBean = new FilterRegistrationBean();
    registrationBean.setFilter(new ShutdownFilter());
    registrationBean.setUrlPatterns(Collections.singleton("/shutdown"));

    return registrationBean;
}

Defining an @Aspect

---

If you send a request to the /shutdown endpoint, assuming the shutdown endpoint is enabled and security does not block the request, the invoke method will be called. You can define an @Aspect to intercept this method call and put your logic there:

@Aspect
@Component
public class ShutdownAspect {
    @Before("execution(* org.springframework.boot.actuate.endpoint.ShutdownEndpoint.invoke())")
    public void runBeforeShutdownHook() {
        // Put your logic here
        System.out.println("Going to shutdown...");
    }
}

Also don't forget to enable the AspectJAutoProxy:

@SpringBootApplication
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class Application { ... }

And spring-aspects dependency:

compile 'org.springframework:spring-aspects'