用ZooKeeper做为注册中心搭建基于Spring Cloud实现服务注册与发现

╰半橙微兮° 2022-03-09 06:36 174阅读 0赞

**前提：**

先安装好ZooKeeper的环境，搭建参考：[http://www.cnblogs.com/EasonJim/p/7482961.html][http_www.cnblogs.com_EasonJim_p_7482961.html]

**说明：**

[![417876-20170930092537809-335943735.png][]][417876-20170930092537809-335943735.png]

可以再简单的理解为有两方协作，一个是服务提供这，另一个是服务消费者。

**搭建实例：**

说明：基于Maven的模块工程

**父工程POM：**

![复制代码][copycode.gif]

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <groupId>com.jsoft.testzookeeper</groupId>
        <artifactId>zookeeperdemo</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <packaging>pom</packaging>
        <name>ZooKeeperDemo</name>
        <description>This is ZookKeeperDemo</description>
        
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.4.5.RELEASE</version>
        </parent>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-actuator</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-hystrix</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-ribbon</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>    
            
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <scope>test</scope>
            </dependency>    
        </dependencies>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>Camden.SR7</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
                
                <dependency>
                    <groupId>junit</groupId>
                    <artifactId>junit</artifactId>
                    <version>3.8.1</version>
                    <scope>test</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>    
        
        <modules>
            <module>zookeeperservice</module>
            <module>zookeeperclient</module>
        </modules>
    </project>

![复制代码][copycode.gif]

**服务提供者POM：**

![复制代码][copycode.gif]

<?xml version="1.0"?>
    <project
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
        xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <modelVersion>4.0.0</modelVersion>
        <parent>
            <groupId>com.jsoft.testzookeeper</groupId>
            <artifactId>zookeeperdemo</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </parent>
        <groupId>com.jsoft.testzookeeper</groupId>
        <artifactId>zookeeperservice</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>zookeeperservice</name>
        <url>http://maven.apache.org</url>
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        </properties>
        <dependencies>
            
        </dependencies>
    </project>

![复制代码][copycode.gif]

**application.properties：**

server.port=8800
    spring.application.name=/service-zookeeper
    spring.cloud.zookeeper.discovery.root=/spring-cloud-service
    spring.cloud.zookeeper.connect-string=localhost:2181

说明：定义端口，应用的名称，服务在ZK的路径，ZK的服务器地址，其中ZK的服务器地址可以有多个，用逗号隔开。

**HelloController：**

**服务接口**

![复制代码][copycode.gif]

package com.jsoft.testzookeeper.service.controller;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    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;
    
    @RestController
    public class HelloController {
    
        private static final Logger log = LoggerFactory.getLogger(HelloController.class);
    
        @RequestMapping(value = "/hello", method = RequestMethod.GET)
        public String sayHello(@RequestParam(name = "name") String name) {
            log.info("param:name->{}", name);
            return "hello: " + name;
        }
    }

![复制代码][copycode.gif]

**App：**

**程序入口**

![复制代码][copycode.gif]

package com.jsoft.testzookeeper.service;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    
    @SpringBootApplication
    @EnableDiscoveryClient
    public class App 
    {
        public static void main( String[] args )
        {
            SpringApplication.run(App.class, args);
        }
    }

![复制代码][copycode.gif]

说明：其中要@EnableDiscoveryClient标注为服务发现注解。

**服务消费者POM：**

![复制代码][copycode.gif]

<?xml version="1.0"?>
    <project
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
        xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <modelVersion>4.0.0</modelVersion>
        <parent>
            <groupId>com.jsoft.testzookeeper</groupId>
            <artifactId>zookeeperdemo</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </parent>
        <groupId>com.jsoft.testzookeeper</groupId>
        <artifactId>zookeeperclient</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>zookeeperclient</name>
        <url>http://maven.apache.org</url>
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        </properties>
        <dependencies>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-feign</artifactId>
            </dependency>
        </dependencies>
    </project>

![复制代码][copycode.gif]

说明：由于使用了Feign客户端，所以引入Feign依赖。

**application.properties：**

![复制代码][copycode.gif]

server.port=8810
    spring.application.name=/client-zookeeper
    spring.cloud.zookeeper.discovery.register=false
    spring.cloud.zookeeper.discovery.root=/spring-cloud-service
    spring.cloud.zookeeper.connect-string=localhost:2181
    spring.cloud.zookeeper.dependencies.service-zookeeper.required=true
    spring.cloud.zookeeper.dependencies.service-zookeeper.path=/service-zookeeper
    spring.cloud.zookeeper.dependencies.service-zookeeper.loadBalancerType=ROUND_ROBIN

![复制代码][copycode.gif]

说明：由于服务提供者的应用名使用了斜杠，所以必须采用依赖关系spring.cloud.zookeeper.dependencies进行别名的选择，注意，使用了这个之后要引入actuator健康监控组件，不然调用时会报错。

**App：**

**程序入口**

![复制代码][copycode.gif]

package com.jsoft.testzookeeper.client;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.netflix.feign.EnableFeignClients;
    
    @SpringBootApplication
    @EnableDiscoveryClient
    @EnableCircuitBreaker
    @EnableFeignClients
    public class App 
    {
        public static void main( String[] args )
        {
            SpringApplication.run(App.class,args);
        }
    }

![复制代码][copycode.gif]

说明：@EnableCircuitBreaker为断路器的支持，@EnableFeignClients为Feign客户端的支持。

**Client的实现：**

主要有两种，基于RestTemplate和Feign

**RestTemplate**

![复制代码][copycode.gif]

package com.jsoft.testzookeeper.client.service;
    
    import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.web.client.RestTemplate;
    
    @Service
    public class HelloService {
    
        @Autowired
        private RestTemplate restTemplate;
    
        @HystrixCommand(fallbackMethod = "sayHelloFallback")
        public String sayHello(String name) {
            return restTemplate.getForEntity("http://service-zookeeper/hello?name=" + name, String.class).getBody();
        }
    
        private String sayHelloFallback(String name) {
            return "service error";
        }
    }

![复制代码][copycode.gif]

说明：@HystrixCommand为断路器写法。

**Feign**

![复制代码][copycode.gif]

package com.jsoft.testzookeeper.client.service;
    
    import org.springframework.cloud.netflix.feign.FeignClient;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    
    import com.jsoft.testzookeeper.client.service.fallback.FeignFallback;
    
    @FeignClient(value = "service-zookeeper", fallback = FeignFallback.class)
    public interface ServiceFeign {
    
        @RequestMapping(value = "/hello")
        String sayHello(@RequestParam(name = "name") String name);
    }

![复制代码][copycode.gif]

说明：fallback为断路器回调。

**消费服务：**

![复制代码][copycode.gif]

package com.jsoft.testzookeeper.client.controller;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    
    import com.jsoft.testzookeeper.client.service.HelloService;
    import com.jsoft.testzookeeper.client.service.ServiceFeign;
    
    @RestController
    public class HelloController {
    
        @Autowired
        private HelloService helloService;
    
        @Autowired
        private ServiceFeign serviceFeign;
    
        @RequestMapping(value = "hello")
        public String hello(@RequestParam String name) {
            return helloService.sayHello(name);
        }
    
        @RequestMapping(value = "hello2")
        public String hello2(@RequestParam String name) {
            return serviceFeign.sayHello(name);
        }
    }

![复制代码][copycode.gif]

**总结：**

Spring Cloud在服务发现和注册上其实很多坑，上面展示的只是核心代码，最全的还是参考例子代码进行调试。

Maven示例：

[https://github.com/easonjim/spring-cloud-demo/tree/master/ZooKeeper][https_github.com_easonjim_spring-cloud-demo_tree_master_ZooKeeper]

参考：

[http://theseus.iteye.com/blog/2366237][http_theseus.iteye.com_blog_2366237]

[http://www.cnblogs.com/skyblog/p/5133752.html][http_www.cnblogs.com_skyblog_p_5133752.html]

[http://blog.csdn.net/mn960mn/article/details/51803703][http_blog.csdn.net_mn960mn_article_details_51803703]

[http://www.jianshu.com/p/775c363d0fda][http_www.jianshu.com_p_775c363d0fda]

==>如有问题，请联系我：easonjim\#163.com，或者下方发表评论。<==

[http_www.cnblogs.com_EasonJim_p_7482961.html]: http://www.cnblogs.com/EasonJim/p/7482961.html
[417876-20170930092537809-335943735.png]: /images/20220309/7ee21ab026c24d5384851e55a8511168.png
[copycode.gif]: /images/20220309/32e6d65d5e4040a2b535d837bbcdfbfb.png
[https_github.com_easonjim_spring-cloud-demo_tree_master_ZooKeeper]: https://github.com/easonjim/spring-cloud-demo/tree/master/ZooKeeper
[http_theseus.iteye.com_blog_2366237]: http://theseus.iteye.com/blog/2366237
[http_www.cnblogs.com_skyblog_p_5133752.html]: http://www.cnblogs.com/skyblog/p/5133752.html
[http_blog.csdn.net_mn960mn_article_details_51803703]: http://blog.csdn.net/mn960mn/article/details/51803703
[http_www.jianshu.com_p_775c363d0fda]: http://www.jianshu.com/p/775c363d0fda