玩转SpringCloud专题(七)-SpringCloud注册中心Eureka优雅停服

由于eureka的自我保护机制，直接对服务进行停止会使得eureka serve进入自我保护模式。服务并不会从列表中删除。

1.不需要再 Eureka Server 中配置关闭自我保护

首先将服务开启自我保护
然后让对应的服务具有优雅停服的功能，比如provider服务

2.需要再服务中添加 actuator.jar 包

需要添加actuator的jar包，只需要将pom文件改成

<dependency>
          <groupId>org.springframework.cloud</groupId>
           <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
  </dependency>
或者
<dependency>
　　　　　 <groupId>org.springframework.boot</groupId>
　　　　 　　<artifactId>spring-boot-starter-actuator</artifactId> 
</dependency>

注意actuator的依赖在spring-cloud-starter-eureka-server中，所以我们要将Eureka的依赖修改为此

application.yml全局配置文件添加如下

management:
  endpoints:
    web:
      exposure:
        include: shutdown #暴漏shutdown端点服务
  endpoint:
    shutdown:
      enabled: true

3.启动服务

然后在postman里边用post请求方式，请求如下地址

http://ip:port/actuator/shutdown

4.发送一个关闭服务的 URL 请求

我们也可以通过HttpClient来发送一个停止服务的请求

<dependency>
   <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.8</version>
</dependency>

创建一个java类

package com.bruceliu.utils;

/**
 * @BelongsProject: springcloud0310
 * @BelongsPackage: com.bruceliu.utils
 * @Author: bruceliu
 * @QQ:1241488705
 * @CreateTime: 2020-03-10 18:35
 * @Description: TODO
 */
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * @program: springcloud-eureka-consumer
 * @description: httpClient停止服务
 * @author: 波波烤鸭
 * @create: 2019-06-03 21:01
 */
public class HttpClientUtil {
    public static String doGet(String url, Map<String, String> param) {

        // 创建Httpclient对象
        CloseableHttpClient httpclient = HttpClients.createDefault();

        String resultString = "";
        CloseableHttpResponse response = null;
        try {
            // 创建uri
            URIBuilder builder = new URIBuilder(url);
            if (param != null) {
                for (String key : param.keySet()) {
                    builder.addParameter(key, param.get(key));
                }
            }
            URI uri = builder.build();

            // 创建http GET请求
            HttpGet httpGet = new HttpGet(uri);

            // 执行请求
            response = httpclient.execute(httpGet);
            // 判断返回状态是否为200
            if (response.getStatusLine().getStatusCode() == 200) {
                resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (response != null) {
                    response.close();
                }
                httpclient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return resultString;
    }

    public static String doGet(String url) {
        return doGet(url, null);
    }

    public static String doPost(String url, Map<String, String> param) {
        // 创建Httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String resultString = "";
        try {
            // 创建Http Post请求
            HttpPost httpPost = new HttpPost(url);
            // 创建参数列表
            if (param != null) {
                List<NameValuePair> paramList = new ArrayList<>();
                for (String key : param.keySet()) {
                    paramList.add(new BasicNameValuePair(key, param.get(key)));
                }
                // 模拟表单
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList, "utf-8");
                httpPost.setEntity(entity);
            }
            // 执行http请求
            response = httpClient.execute(httpPost);
            resultString = EntityUtils.toString(response.getEntity(), "utf-8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                response.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        return resultString;
    }

    public static String doPost(String url) {
        return doPost(url, null);
    }

    public static String doPostJson(String url, String json) {
        // 创建Httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String resultString = "";
        try {
            // 创建Http Post请求
            HttpPost httpPost = new HttpPost(url);
            // 创建请求内容
            StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);
            httpPost.setEntity(entity);
            // 执行http请求
            response = httpClient.execute(httpPost);
            resultString = EntityUtils.toString(response.getEntity(), "utf-8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                response.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        return resultString;
    }

    public static void main(String[] args) {
        String url = "http://127.0.0.1:8080/actuator/shutdown";
        //该url必须要使用dopost方式来发送
        HttpClientUtil.doPost(url);
    }
}

执行main方法，观察服务提供者及注册中心注册的服务

服务端的服务被停止了