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

梦里梦外; 2023-07-08 09:03 6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 核心代码
         *   *  4.1 Service 层-Feign 注解方式调用服务
             *  4.2 Controller 层
             *  4.3 SpringBoot 启动类
         *  5 测试
         *  6 参考资料推荐
         *  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]

Spring Cloud Zookeeper 分布式服务调用-Ribbon 方式可参考:

[34 Spring Boot 2.2 集成 Spring Cloud Zookeeper - Ribbon 分布式服务消费者 — 2020-02-25][34 Spring Boot 2.2 _ Spring Cloud Zookeeper - Ribbon _ _ 2020-02-25]

本文将介绍通过 Feign 调用 Spring Cloud Zookeeper 服务.

`Feign` 内部集成 `Ribbon`,通过注解的方式，使用更加方便

### 2 核心 Maven 依赖 ###

./cloud-zookeeper-feign/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>
    
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
            </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-feign/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-feign/src/main/resources/application.yml

## Application config
    
    ## Server
    server:
      port: 8102
    
    ## Spring config
    spring:
      application:
        name: cloud-zookeeper-feign

### 4 核心代码 ###

#### 4.1 Service 层-Feign 注解方式调用服务 ####

./cloud-zookeeper-feign/src/main/java/com/ljq/demo/springboot/cloud/zookeeper/feign/service/CloudZookeeperFeignService.java

package com.ljq.demo.springboot.cloud.zookeeper.feign.service;
    
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.http.MediaType;
    import org.springframework.stereotype.Service;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    
    /** * @Description: Spring Cloud Zookeeper 分布式服务消费者-Feign 业务层 * @Author: junqiang.lu * @Date: 2020/2/25 */
    @FeignClient(value = "cloud-zookeeper-provider")
    @Service("cloudZookeeperFeignService")
    public interface CloudZookeeperFeignService { 
    
    
        /** * 打印用户名称 * * @param name * @return */
        @GetMapping(value = "/api/cloud/zookeeper/hello", produces = { MediaType.APPLICATION_JSON_VALUE})
        String sayHello(@RequestParam("name") String name);
    
    
    }

使用 `@FeignClient(value = "cloud-zookeeper-provider")` 注解即可实现对 Spring Cloud Zookeeper 服务的调用,其中 `cloud-zookeeper-provide` 为服务名称(`serviceId`,`zookeeper` 默认将 `spring.application.name` 作为服务名称)

**注意:`Feign` 只支持一种请求方式**,即如上述代码中所示,使用 `@GetMapping` 指定`GET` 方式请求,也可以使用 `@PostMapping` 指定 `POST` 请求，但是不能使用 `@RequestMapping(method = {RequestMethod.GET, RequestMethod.POST})` 指定两种请求方式,否则会在启动时抛出异常，导致启动失败

#### 4.2 Controller 层 ####

./cloud-zookeeper-feign/src/main/java/com/ljq/demo/springboot/cloud/zookeeper/feign/controller/CloudZookeeperFeignController.java

package com.ljq.demo.springboot.cloud.zookeeper.feign.controller;
    
    import com.ljq.demo.springboot.cloud.zookeeper.feign.service.CloudZookeeperFeignService;
    import org.springframework.beans.factory.annotation.Autowired;
    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;
    
    import java.util.Date;
    
    /** * @Description: Spring Cloud Zookeeper 分布式服务消费者-Feign 控制层 * @Author: junqiang.lu * @Date: 2020/2/25 */
    @RestController
    @RequestMapping("/api/cloud/zookeeper/feign")
    public class CloudZookeeperFeignController { 
    
        @Autowired
        private CloudZookeeperFeignService cloudZookeeperFeignService;
    
        /** * 打印用户名称 * * @param name * @return */
        @RequestMapping(value = "/sayHello", method = { RequestMethod.GET, RequestMethod.POST})
        public String sayHello(@RequestParam("name") String name) { 
            System.out.println(new Date() + "-" + name);
            return cloudZookeeperFeignService.sayHello(name);
        }
    
    
    }

#### 4.3 SpringBoot 启动类 ####

/Users/ljq/develop/repository/git/springBootDemo/cloud-zookeeper-feign/src/main/java/com/ljq/demo/springboot/cloud/zookeeper/feign/CloudZookeeperFeignApplication.java

package com.ljq.demo.springboot.cloud.zookeeper.feign;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    /** * @author junqiang.lu */
    @EnableFeignClients
    @EnableDiscoveryClient
    @SpringBootApplication
    public class CloudZookeeperFeignApplication { 
    
        public static void main(String[] args) { 
            SpringApplication.run(CloudZookeeperFeignApplication.class, args);
        }
    
    }

`@EnableDiscoveryClient` 用于发现 Spring cloud 服务

`@EnableFeignClients` 用于启用 `Feign` 来请求 Spring Cloud Zookeeper 服务

### 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

请求接口:

GET http://127.0.0.1:8102/api/cloud/zookeeper/feign/sayHello?name=Are%20you%20%E6%AC%A7%E5%85%8B

返回参数:

Hello !Are you 欧克
    server port : 8100
    server timestamp: 1582615867196

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 `Feign` 调用 `Cloud Zoopeeper` 服务成功

### 6 参考资料推荐 ###

[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
[34 Spring Boot 2.2 _ Spring Cloud Zookeeper - Ribbon _ _ 2020-02-25]: https://blog.csdn.net/Mrqiang9001/article/details/104495167
[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
[springcloud ribbon_ _LoadBalanced]: https://blog.csdn.net/xiao_jun_0820/article/details/78917215
[https_github.com_Flying9001_springBootDemo]: https://github.com/Flying9001/springBootDemo
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