如何在Spring Boot Actuator中添加依赖服务的健康状态信息

1. 引入Actuator依赖 #

首先在service-a的构建文件中添加Spring Boot Actuator依赖：

Maven（pom.xml） #

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

Gradle（build.gradle） #

implementation 'org.springframework.boot:spring-boot-starter-actuator'

2. 配置端点暴露与详情展示 #

在application.yml或application.properties中开启健康端点并配置详情显示：

application.yml #

management:
  endpoints:
    web:
      exposure:
        include: health  # 仅暴露health端点，也可使用*暴露所有端点
  endpoint:
    health:
      show-details: always  # 始终显示健康详情，生产环境可设为when-authorized

3. 自定义HealthIndicator检查依赖服务 #

为每个依赖服务（service-b、service-c）编写自定义HealthIndicator，通过调用其健康端点判断状态：

示例：ServiceBHealthIndicator #

import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;

@Component
public class ServiceBHealthIndicator implements HealthIndicator {

    private final RestTemplate restTemplate;

    public ServiceBHealthIndicator(RestTemplate restTemplate) {
        this.restTemplate = restTemplate;
    }

    @Override
    public Health health() {
        try {
            // 替换为service-b实际的健康端点地址
            String healthUrl = "http://service-b/actuator/health";
            restTemplate.getForObject(healthUrl, String.class);
            return Health.up().withDetail("service-b", "运行正常").build();
        } catch (Exception e) {
            return Health.down()
                    .withDetail("service-b", "服务不可达")
                    .withDetail("错误信息", e.getMessage())
                    .build();
        }
    }
}

配置RestTemplate Bean #

需要在service-a中注册RestTemplate的Bean：

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

@Configuration
public class RestTemplateConfig {

    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

同理实现ServiceCHealthIndicator #

复制上述代码，将service-b相关内容替换为service-c即可。

4. （可选）结合服务发现动态获取实例 #

如果依赖服务注册到Eureka、Nacos等服务发现组件，可通过DiscoveryClient动态获取实例地址，避免硬编码：

引入服务发现依赖（以Eureka为例） #

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

修改HealthIndicator #

import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;

import java.util.List;

@Component
public class ServiceBHealthIndicator implements HealthIndicator {

    private final RestTemplate restTemplate;
    private final DiscoveryClient discoveryClient;

    public ServiceBHealthIndicator(RestTemplate restTemplate, DiscoveryClient discoveryClient) {
        this.restTemplate = restTemplate;
        this.discoveryClient = discoveryClient;
    }

    @Override
    public Health health() {
        List<String> instanceUrls = discoveryClient.getInstances("service-b").stream()
                .map(instance -> instance.getUri() + "/actuator/health")
                .toList();

        if (instanceUrls.isEmpty()) {
            return Health.down().withDetail("service-b", "无可用实例").build();
        }

        try {
            // 检查第一个可用实例，也可扩展为检查多个实例
            restTemplate.getForObject(instanceUrls.get(0), String.class);
            return Health.up()
                    .withDetail("service-b", "运行正常")
                    .withDetail("可用实例数", instanceUrls.size())
                    .build();
        } catch (Exception e) {
            return Health.down()
                    .withDetail("service-b", "实例不可用")
                    .withDetail("错误信息", e.getMessage())
                    .build();
        }
    }
}

5. 验证效果 #

启动所有服务后，访问http://service-a/actuator/health，即可看到包含service-b、service-c健康状态的响应，示例如下：

{
  "status": "UP",
  "components": {
    "service-b": {
      "status": "UP",
      "details": {
        "service-b": "运行正常"
      }
    },
    "service-c": {
      "status": "UP",
      "details": {
        "service-c": "运行正常"
      }
    }
  }
}

若某依赖服务宕机，对应组件状态会变为DOWN，默认情况下整体健康状态也会变为DOWN（可通过management.health.defaults.enabled=false自定义聚合规则）。

内容的提问来源于stack exchange，提问作者user352290