Spring Boot actuator endpoints

last modified July 31, 2023

In this article we show how to enable actuator endpoints in a Spring Boot application.

Spring Boot is a popular application framework for creating enterprise application in Java, Kotlin, or Groovy.

Actuator endpoints are used to provide information and monitor our applications. They are enabled with the spring-boot-actuator module.

The following is a partial is of built-in actuator endpoints.

- beans - displays a complete list of all Spring beans

- caches - exposes available caches

- env - exposes properties from Spring's ConfigurableEnvironment

- health - shows application health information

- metrics - shows metrics information for the current application

- shutdown - lets the application be gracefully shutdown

- threaddump - performs a thread dump.

The actuator endpoint returns a list of available endpoints. Endpoints are available for HTTP and JMX.

By default, only the health endpoint is enabled. We can enable endpoints via the management.endpoints.web.exposure.include property

management.endpoints.web.exposure.include=*

Here we enable most endpoints with the star operator.

management.endpoints.web.exposure.include=health,info,beans,env

We can enable only specific endpoints.

management.endpoint.shutdown.enabled=true

Some endpoints, such as shutdown, must be enabled explicitly due to their sensitivity.

Spring Boot actuator example

The following application enables actuator endpoints.

build.gradle … src ├───main │ ├───java │ │ └───com │ │ └───zetcode │ │ │ Application.java │ │ ├───actuator │ │ │ MyEndpoint.java │ │ └───controller │ │ HelloController.java │ └───resources │ application.properties └───test ├───java └───resources

This is the project structure.

build.gradle

plugins { id ‘org.springframework.boot’ version ‘3.1.1’ id ‘io.spring.dependency-management’ version ‘1.1.0’ id ‘java’ }

group = ‘com.zetcode’ version = ‘0.0.1-SNAPSHOT’ sourceCompatibility = ‘17’

repositories { mavenCentral() }

dependencies { implementation ‘org.springframework.boot:spring-boot-starter-web’ implementation ‘org.springframework.boot:spring-boot-starter-actuator’ }

This is the Gradle build file. We include the spring-boot-starter-actuator module.

resources/application.properties

spring.main.banner-mode=off management.endpoints.web.exposure.include=health,beans,env,now

In the Application properties file, we enable the health, beans, env, and now endpoints. The now endpoint is a custom one.

com/zetcode/controller/MyController.java

package com.zetcode.controller;

import org.springframework.http.ResponseEntity; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController;

@RestController public class HelloController {

@GetMapping(path = "/hello")
public ResponseEntity<String> hello() {

    return ResponseEntity.ok("hello there!");
}

}

The application has a simple controller with one mapping.

com/zetcode/actuator/MyEndpoint.java

package com.zetcode.actuator;

import org.springframework.boot.actuate.endpoint.annotation.Endpoint; import org.springframework.boot.actuate.endpoint.annotation.ReadOperation; import org.springframework.context.annotation.Bean; import org.springframework.stereotype.Component;

import java.time.LocalDateTime;

@Endpoint(id=“now”) @Component public class MyEndpoint {

@ReadOperation
@Bean
public LocalDateTime now() {
    return LocalDateTime.now();
}

}

We create a custom actuator with @Endpoint. It returns the current datetime.

com/zetcode/Application.java

package com.zetcode;

import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication public class Application {

public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
}

}

The Application sets up the Spring Boot application.

$ ./gradlew bootRun

We build the application and run it.

$ curl localhost:8080/actuator/health {“status”:“UP”} $ curl localhost:8080/actuator/now “2023-07-31T16:38:54.3963529”

We check two endpoints.

In this tutorial we have worked with actuator endpoints.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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