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

spring.application.name=boot


# server.servlet.context-path=/boot
# management.server.servlet.context-path=/boot
# JVM (Micrometer)要求給應用設置commonTag
management.metrics.tags.application=${spring.application.name}
#去掉重復的metrics
spring.metrics.servo.enabled=false

management.endpoint.metrics.enabled=true
management.endpoint.metrics.sensitive=false
#顯式配置不需要權限驗證對外開放的端點
management.endpoints.web.exposure.include=*
management.endpoints.jmx.exposure.include=*

management.endpoint.health.show-details=always
#Actuator 的 Web 訪問方式的根地址為 /actuator，可以通過 management.endpoints.web.base-path 參數(shù)進行修改
management.endpoints.web.base-path=/actuator
management.metrics.export.prometheus.enabled=true

/**
  * @Author jeffSmile
  * @Date 下午 6:10 2020/5/24 0024
  * @Description 定義一個接口，來把耗時很長的任務提交到這個 demoThreadPool 線程池，以模擬線程池隊列滿的情況
  **/

 @GetMapping("slowTask")
 public void slowTask() {
  ThreadPoolProvider.getDemoThreadPool().execute(() -> {
   try {
    TimeUnit.HOURS.sleep(1);
   } catch (InterruptedException e) {
   }
  });
 }

package com.mongo.boot.service;

import jodd.util.concurrent.ThreadFactoryBuilder;

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class ThreadPoolProvider {

 //一個工作線程的線程池，隊列長度10
 private static ThreadPoolExecutor demoThreadPool = new ThreadPoolExecutor(
   1, 1,
   2, TimeUnit.SECONDS,
   new ArrayBlockingQueue<>(10),
   new ThreadFactoryBuilder().setNameFormat("demo-threadpool-%d").get());
 //核心線程數(shù)10，最大線程數(shù)50的線程池，隊列長度50
 private static ThreadPoolExecutor ioThreadPool = new ThreadPoolExecutor(
   10, 50,
   2, TimeUnit.SECONDS,
   new ArrayBlockingQueue<>(100),
   new ThreadFactoryBuilder().setNameFormat("io-threadpool-%d").get());

 public static ThreadPoolExecutor getDemoThreadPool() {
  return demoThreadPool;
 }

 public static ThreadPoolExecutor getIOThreadPool() {
  return ioThreadPool;
 }
}

package com.mongo.boot.service;

import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ThreadPoolExecutor;

/**
 * @Author jeffSmile
 * @Date 下午 6:12 2020/5/24 0024
 * @Description 自定義的 HealthIndicator 類，用于單一線程池的健康狀態(tài)
 **/

public class ThreadPoolHealthIndicator implements HealthIndicator {
 private ThreadPoolExecutor threadPool;

 public ThreadPoolHealthIndicator(ThreadPoolExecutor threadPool) {
  this.threadPool = threadPool;
 }

 @Override
 public Health health() {
  //補充信息
  Map<String, Integer> detail = new HashMap<>();
  //隊列當前元素個數(shù)
  detail.put("queue_size", threadPool.getQueue().size());
  //隊列剩余容量
  detail.put("queue_remaining", threadPool.getQueue().remainingCapacity());

  //如果還有剩余量則返回UP，否則返回DOWN
  if (threadPool.getQueue().remainingCapacity() > 0) {
   return Health.up().withDetails(detail).build();
  } else {
   return Health.down().withDetails(detail).build();
  }
 }
}

package com.mongo.boot.service;

import org.springframework.boot.actuate.health.CompositeHealthContributor;
import org.springframework.boot.actuate.health.HealthContributor;
import org.springframework.boot.actuate.health.NamedContributor;
import org.springframework.stereotype.Component;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/***
 * @Author jeffSmile
 * @Date 下午 6:13 2020/5/24 0024
 * @Description 定義一個 CompositeHealthContributor，來聚合兩個 ThreadPoolHealthIndicator 的實例，
 * 分別對應 ThreadPoolProvider 中定義的兩個線程池
 **/

@Component
public class ThreadPoolsHealthContributor implements CompositeHealthContributor {

 //保存所有的子HealthContributor
 private Map<String, HealthContributor> contributors = new HashMap<>();

 ThreadPoolsHealthContributor() {
  //對應ThreadPoolProvider中定義的兩個線程池
  this.contributors.put("demoThreadPool", new ThreadPoolHealthIndicator(ThreadPoolProvider.getDemoThreadPool()));
  this.contributors.put("ioThreadPool", new ThreadPoolHealthIndicator(ThreadPoolProvider.getIOThreadPool()));
 }

 @Override
 public HealthContributor getContributor(String name) {
  //根據(jù)name找到某一個HealthContributor
  return contributors.get(name);
 }

 @Override
 public Iterator<NamedContributor<HealthContributor>> iterator() {
  //返回NamedContributor的迭代器，NamedContributor也就是Contributor實例+一個命名
  return contributors.entrySet().stream()
    .map((entry) -> NamedContributor.of(entry.getKey(), entry.getValue())).iterator();
 }
}

package com.mongo.boot.config;

import com.mongo.boot.service.ThreadPoolProvider;
import org.springframework.boot.actuate.info.Info;
import org.springframework.boot.actuate.info.InfoContributor;
import org.springframework.stereotype.Component;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ThreadPoolExecutor;


/**
 * @Author jeffSmile
 * @Date 下午 6:37 2020/5/24 0024
 * @Description 通過 Actuator 的 InfoContributor 功能，對外暴露程序內(nèi)部重要組件的狀態(tài)數(shù)據(jù)
 **/

@Component
public class ThreadPoolInfoContributor implements InfoContributor {

 private static Map threadPoolInfo(ThreadPoolExecutor threadPool) {
  Map<String, Object> info = new HashMap<>();
  info.put("poolSize", threadPool.getPoolSize());//當前池大小
  info.put("corePoolSize", threadPool.getCorePoolSize());//設置的核心池大小
  info.put("largestPoolSize", threadPool.getLargestPoolSize());//最大達到過的池大小
  info.put("maximumPoolSize", threadPool.getMaximumPoolSize());//設置的最大池大小
  info.put("completedTaskCount", threadPool.getCompletedTaskCount());//總完成任務數(shù)
  return info;
 }

 @Override
 public void contribute(Info.Builder builder) {
  builder.withDetail("demoThreadPool", threadPoolInfo(ThreadPoolProvider.getDemoThreadPool()));
  builder.withDetail("ioThreadPool", threadPoolInfo(ThreadPoolProvider.getIOThreadPool()));
 }
}

#開啟 JMX
spring.jmx.enabled=true

<dependency>
 <groupId>org.jolokia</groupId>
 <artifactId>jolokia-core</artifactId>
</dependency>