Spring Boot中的监视器简介说明

SpringBoot监视器

Spring boot监视器可帮助
     您访问生产环境中正在运行的应用程序的当前状态

Spring boot actuator是spring启动框架中的重要功能

SpringBoot监视器还有一大用途:
     向相关人员触发警报消息
监视器模块对外提供http url访问的方式检查各种状态

SpringBoot监视器的使用方法

实现思路:
    直接引入相应的依赖
    <dependency>
        <groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-actuator</artifactId>
	 </dependency>

一、引入相关依赖

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-actuator</artifactId>
	<version>2.0.4.RELEASE</version>
</dependency>

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

二、进行相关配置
 
server.tomcat.uri-encoding=UTF-8
# 程序运行端口
server.port=8888
# 监视程序运行端口
management.server.port=8090
# 激活所有的内置Endpoints
management.endpoints.web.exposure.include=*
# 开启shutdown这个endpoint
management.endpoint.shutdown.enabled=true


三、编写监视控制器相关代码
package com.java265.Controller;

import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class MainController{

    @ResponseBody
    @RequestMapping("/GetEndPoints")
    public String GetAllPoint(HttpServletRequest request){
        String path = request.getContextPath();
        String host = request.getServerName();
        String endPointPath = "/actuator";
        StringBuilder sb = new StringBuilder();
        
        sb.append("<h2>Sprig Boot Actuator</h2>");
        sb.append("<ul>");
        String url = "http://" + host + ":8090" + path + endPointPath;
        sb.append("<li><a href='" + url + "'>" + url + "</a></li>");
        sb.append("</ul>");
        return sb.toString();
    }
}



// 访问 http://localhost:8888/GetEndPoints
常用的一些内置endpoint
actuator/health         查看程序健康信息
actuator/metrics        查看监视标准
actuator/beans          列出程序中的Spring BEAN 
actuator/env            列出程序运行所有信息

定义actuator/info特殊endpoint

actuator/info可以自定义一些信息
package com.java265.selfactuator;

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

import org.springframework.boot.actuate.info.Info;
import org.springframework.boot.actuate.info.InfoContributor;
import org.springframework.stereotype.Component;

@Component
public class BuildInfoActuator implements InfoContributor{

    @Override
    public void contribute(Info.Builder builder) {
        Map<String,String> data= new HashMap<String,String>();
        data.put("build.version", "1.0.0");
        builder.withDetail("buildInfo", data);
    }
}

actuator/shutdown需要post请求才能访问
  
package com.java265.Controller;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.client.RestTemplate;

@Controller
public class ShutDownController {

    @ResponseBody
    @RequestMapping(path = "/shutdown")
    public String actuatorShutdown(){
        String url = "http://localhost:8090/actuator/shutdown";
        HttpHeaders headers = new HttpHeaders();
        headers.add("Accept", MediaType.APPLICATION_JSON_VALUE);
        headers.setContentType(MediaType.APPLICATION_JSON);

        RestTemplate restTemplate = new RestTemplate();
        HttpEntity<String> requestBody = new HttpEntity<>("", headers);
        String e = restTemplate.postForObject(url, requestBody, String.class);

        return "Result: " + e;
    }
}