Spring Boot 2.2 集成 Spring Cloud Zookeeper - Ribbon 分布式服务消费者

墨蓝 2023-07-08 05:57 26阅读 0赞

### 文章目录 ###

*   *   *  1 摘要
         *  2 核心 Maven 依赖
         *  3 配置文件
         *   *  3.1 bootstrap.yml
             *  3.2 application.yml
         *  4 核心 Java 类
         *   *  4.1 Service 层服务调用
             *  4.2 Controller 层
             *  4.3 SpringBoot 启动类
         *  5 测试
         *  6 推荐参考资料
         *  7 Github 源码

### 1 摘要 ###

Spring Cloud Zookeeper 分布式服务注册中心搭建可参考:

[33 Spring Boot 2.2 集成 Spring Cloud Zookeeper - 分布式服务注册中心 — 2020-02-23][33 Spring Boot 2.2 _ Spring Cloud Zookeeper - _ _ 2020-02-23]

本文将介绍 Spring Cloud Zookeeper 分布式服务消费者 - Ribbon

### 2 核心 Maven 依赖 ###

./cloud-zookeeper-ribbon/pom.xml

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-zookeeper-all</artifactId>
                <exclusions>
                    <exclusion>
                        <groupId>org.apache.zookeeper</groupId>
                        <artifactId>zookeeper</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
            
            <dependency>
                <groupId>org.apache.zookeeper</groupId>
                <artifactId>zookeeper</artifactId>
                <version>${zookeeper.version}</version>
                <exclusions>
                    <exclusion>
                        <groupId>org.slf4j</groupId>
                        <artifactId>slf4j-log4j12</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>

其中 `${zookeeper.version}` 的版本为 `3.4.12` (**不要随意改版本号,会有兼容性问题**)

**注意: SpringBoot 的版本需要在 2.2及以上**

### 3 配置文件 ###

#### 3.1 bootstrap.yml ####

./cloud-zookeeper-ribbon/src/main/resources/bootstrap.yml

## Application bootstrap config
    
    
    ## spring config
    spring:
      cloud:
        zookeeper:
          connect-string: 172.16.140.10:2181

#### 3.2 application.yml ####

./cloud-zookeeper-ribbon/src/main/resources/application.yml

## Application config
    
    ## Server
    server:
      port: 8101
    
    ## Spring config
    spring:
      application:
        name: cloud-zookeeper-ribbon

### 4 核心 Java 类 ###

#### 4.1 Service 层服务调用 ####

./cloud-zookeeper-ribbon/src/main/java/com/ljq/demo/springboot/cloud/zookeeper/ribbon/service/CloudZookeeperRibbonService.java

package com.ljq.demo.springboot.cloud.zookeeper.ribbon.service;
    
    import org.springframework.stereotype.Service;
    import org.springframework.web.client.RestTemplate;
    
    import javax.annotation.Resource;
    import java.util.Date;
    
    /** * @Description: Spring Cloud Zookeeper Ribbon 服务消费者业务层 * @Author: junqiang.lu * @Date: 2020/2/24 */
    @Service("cloudZookeeperRibbonService")
    public class CloudZookeeperRibbonService { 
    
        /** * Zookeeper 服务注册中心服务名称 */
        private static final String CLOUD_ZOOKEEPER_PROVIDER_NAME = "cloud-zookeeper-provider";
        /** * Zookeeper 服务注册中心接口地址-打印用户名称 */
        private static final String API_PATH_ZOOKEEPER_HELLO = "/api/cloud/zookeeper/hello";
    
    
        @Resource
        private RestTemplate restTemplate;
    
        /** * 打印用户名称 * * @param name * @return */
        public String sayHello(String name) { 
            StringBuilder reqUrl = new StringBuilder("http://");
            reqUrl.append(CLOUD_ZOOKEEPER_PROVIDER_NAME);
            reqUrl.append(API_PATH_ZOOKEEPER_HELLO);
            reqUrl.append("?name=").append(name);
    
            System.out.println(new Date() + "-" + reqUrl.toString());
    
            return restTemplate.getForEntity(reqUrl.toString(), String.class).getBody();
        }
    
    
    }

使用 `RestTemplate` 来请求调用 `Zookeeper` 服务,这里 `Ribbon` 将服务名称(ServiceId) 来替代 ip + 端口(port),`RestTemplate` 默认是正常的 `http` 请求,这里需要对 `RestTemplate` 使用 `Ribbon` 提供的注解 `@LoadBalanced` ，具体使用见 `SpringBoot` 启动类 `com.ljq.demo.springboot.cloud.zookeeper.ribbon.CloudZookeeperRibbonApplication`

关于 `Ribbon` 的 `@LoadBalanced` 注解,其作用是实现客户端负载均衡，具体说明可参考:

[由springcloud ribbon的 @LoadBalanced注解的使用理解][springcloud ribbon_ _LoadBalanced]

#### 4.2 Controller 层 ####

./cloud-zookeeper-ribbon/src/main/java/com/ljq/demo/springboot/cloud/zookeeper/ribbon/controller/CloudZookeeperRibbonController.java

package com.ljq.demo.springboot.cloud.zookeeper.ribbon.controller;
    
    import com.ljq.demo.springboot.cloud.zookeeper.ribbon.service.CloudZookeeperRibbonService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.http.MediaType;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    
    /** * @Description: Spring cloud Zookeeper Ribbon 服务消费者控制层 * @Author: junqiang.lu * @Date: 2020/2/24 */
    @RestController
    @RequestMapping("/api/cloud/zookeeper/ribbon")
    public class CloudZookeeperRibbonController { 
    
        @Autowired
        private CloudZookeeperRibbonService cloudZookeeperRibbonService;
    
    
        /** * 打印用户名称 * * @param name * @return */
        @RequestMapping(value = "/sayHello", method = { RequestMethod.GET, RequestMethod.POST},
                produces = { MediaType.APPLICATION_JSON_VALUE})
        public String sayHello(@RequestParam("name") String name) { 
            return cloudZookeeperRibbonService.sayHello(name);
        }
    
    
    }

#### 4.3 SpringBoot 启动类 ####

./cloud-zookeeper-ribbon/src/main/java/com/ljq/demo/springboot/cloud/zookeeper/ribbon/CloudZookeeperRibbonApplication.java

package com.ljq.demo.springboot.cloud.zookeeper.ribbon;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.client.loadbalancer.LoadBalanced;
    import org.springframework.context.annotation.Bean;
    import org.springframework.web.client.RestTemplate;
    
    /** * @author junqiang.lu */
    @EnableDiscoveryClient
    @SpringBootApplication
    public class CloudZookeeperRibbonApplication { 
    
        public static void main(String[] args) { 
            SpringApplication.run(CloudZookeeperRibbonApplication.class, args);
        }
    
        @LoadBalanced
        @Bean
        RestTemplate restTemplate(){ 
            return new RestTemplate();
        }
    
    
    }

`@EnableDiscoveryClient` 该注解可用于发现 `Cloud` 服务

`@LoadBalanced` 用于负载均衡,这里必须手动注入 `RestTemplate`,并使用 `@LoadBalanced` 注解，否则， `RestTemplate` 默认使用正常的 `http` 请求

### 5 测试 ###

由于本次测试需要调用 `Spring Cloud Zookeeper` 服务，因此服务注册中心的项目(`cloud-zookeeper-provider`)必须先启动

接口请求:

GET http://127.0.0.1:8101/api/cloud/zookeeper/ribbon/sayHello?name=Are%20you%20%E6%AC%A7%E5%85%8B

返回结果:

Hello !Are you 欧克
    server port : 8100
    server timestamp: 1582599140197

从返回的结果中可以看出,返回的端口为服务注册中心项目( `cloud-zoopeeper-provider`)的http端口,使用 `Ribbon` 调用 `Cloud Zoopeeper` 服务成功

### 6 推荐参考资料 ###

[官方文档 Spring Cloud Zookeeper][Spring Cloud Zookeeper]

[Zookeeper 完整系列教程 Spring-Cloud-Zookeeper-Based-Demo][Zookeeper _ Spring-Cloud-Zookeeper-Based-Demo]

[由springcloud ribbon的 @LoadBalanced注解的使用理解][springcloud ribbon_ _LoadBalanced]

### 7 Github 源码 ###

**Gtihub 源码地址** : [https://github.com/Flying9001/springBootDemo][https_github.com_Flying9001_springBootDemo]

个人公众号:**404Code**,分享半个互联网人的技术与思考，感兴趣的可以关注.  
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[33 Spring Boot 2.2 _ Spring Cloud Zookeeper - _ _ 2020-02-23]: https://blog.csdn.net/Mrqiang9001/article/details/104474415
[springcloud ribbon_ _LoadBalanced]: https://blog.csdn.net/xiao_jun_0820/article/details/78917215
[Spring Cloud Zookeeper]: https://cloud.spring.io/spring-cloud-zookeeper/reference/html
[Zookeeper _ Spring-Cloud-Zookeeper-Based-Demo]: https://liuyehcf.github.io/2018/07/13/Spring-Cloud-Zookeeper-Based-Demo
[https_github.com_Flying9001_springBootDemo]: https://github.com/Flying9001/springBootDemo
[404Code]: https://img-blog.csdn.net/20181010223005114?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L01ycWlhbmc5MDAx/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70