Spring Cloud学习--Spring Cloud Zookeeper 服务注册与发现

布满荆棘的人生 2022-05-26 10:57 246阅读 0赞

之前几篇博客我们已经介绍过使用Eureka和Consul作为注册中心的实现及代码示例，这边博客我们学习了解一下Spring Cloud给我们提供的用Zookeeper作为注册中心的实现机制。

####  Zookeeper ####

Zookeeper是一个高性能，分布式的，开源分布式应用协调服务。它提供了简单原始的功能，分布式应用可以基于它实现更高级的服务，比如同步，配置管理，集群管理，名空间。它被设计为易于编程，使用文件系统目录树作为数据模型。

1、Zookeeper安装启动

官网下载：http://zookeeper.apache.org/releases.html\#download

解压运行：zkServer.cmd

![70][]

### 服务提供者 ###

服务提供者将自己的地址信息暴露到Zookeeper中即可，简单来说就是一些IP、端口、实例名等基本信息

1、pom.mxl配置

<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">
    	<parent>
    	    <groupId>org.springframework.boot</groupId>
    	    <artifactId>spring-boot-starter-parent</artifactId>
    	    <version>1.5.10.RELEASE</version>
    	</parent>
    	
    	<dependencyManagement>
    	    <dependencies>
    	        <dependency>
    	            <groupId>org.springframework.cloud</groupId>
    	            <artifactId>spring-cloud-dependencies</artifactId>
    	            <version>Edgware.SR3</version>
    	            <type>pom</type>
    	            <scope>import</scope>
    	        </dependency>
    	    </dependencies>
    	</dependencyManagement>
    	<modelVersion>4.0.0</modelVersion>
    	<groupId>com.tianjunwei</groupId>
    	<artifactId>TJWspringCloud-zookeeper</artifactId>
    	<version>1.0.0-SNAPSHOT</version>
    	<packaging>jar</packaging>
    	<name>TJWspringCloud-zookeeper</name>
    	<properties>
    		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    	</properties>
    	<dependencies>
    		<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>ch.qos.logback</groupId>  
                <artifactId>logback-core</artifactId>  
            </dependency>  
            <dependency>  
                <groupId>ch.qos.logback</groupId>  
                <artifactId>logback-classic</artifactId>  
            </dependency>  
            <dependency>  
                <groupId>ch.qos.logback</groupId>  
                <artifactId>logback-access</artifactId>  
            </dependency>  
    	
    	</dependencies>
    	<build>
    		<resources>
    			<resource>
    				<directory>src/main/java</directory>
    				<includes>
    					<include>**/*.xml</include>
    				</includes>
    			</resource>
    			<resource>
    				<directory>src/test/java</directory>
    				<includes>
    					<include>**/*.xml</include>
    				</includes>
    			</resource>
    			<resource>
    				<directory>src/main/resources</directory>
    				<includes>
    					<include>**/*.*</include>
    				</includes>
    			</resource>
    		</resources>
    		<plugins>  
    			<plugin>
    				<groupId>org.springframework.boot</groupId>
    				<artifactId>spring-boot-maven-plugin</artifactId>
    			</plugin>
    			
    	        <plugin>  
    	            <groupId>org.apache.maven.plugins</groupId>  
    	            <artifactId>maven-compiler-plugin</artifactId>  
    	            <version>2.0.2</version>  
    	            <configuration>  
    	                <source>1.8</source>  
    	                <target>1.8</target>  
    	            </configuration>  
    	        </plugin>  
    	    </plugins>  
    	</build>
    </project>

2、在application.properties中添加服务提供者自身及Zookeeper的相关配置

server.port=8822
    spring.application.name=spring-cloud-zookeeper
    spring.cloud.zookeeper.connectString=localhost:2181
    spring.cloud.zookeeper.discovery.instanceHost=localhost
    spring.cloud.zookeeper.discovery.instancePort=${server.port}

3、服务提供者相关代码：

服务提供者暴露服务名为spring-cloud-zookeeper的服务。

import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @Configuration
    @EnableAutoConfiguration
    @EnableDiscoveryClient
    @RestController
    public class ZookeeperMain {
    
      @RequestMapping("/hi")
      public String home() {
        return "Hello zookeeper";
      }
    
      public static void main(String[] args) {
        SpringApplication.run(ZookeeperMain.class, args);
      }
    
    }

### 服务消费者 ###

服务消费者同样注册到Zookeeper中，从zk中获取到所需要的服务信息。

1、pom.xml中配置

<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">
    	<parent>
    	    <groupId>org.springframework.boot</groupId>
    	    <artifactId>spring-boot-starter-parent</artifactId>
    	    <version>1.5.10.RELEASE</version>
    	</parent>
    	
    	<dependencyManagement>
    	    <dependencies>
    	        <dependency>
    	            <groupId>org.springframework.cloud</groupId>
    	            <artifactId>spring-cloud-dependencies</artifactId>
    	            <version>Edgware.SR3</version>
    	            <type>pom</type>
    	            <scope>import</scope>
    	        </dependency>
    	    </dependencies>
    	</dependencyManagement>
    	<modelVersion>4.0.0</modelVersion>
    	<groupId>com.tianjunwei</groupId>
    	<artifactId>TJWspringCloud-zookeeper-client</artifactId>
    	<version>1.0.0-SNAPSHOT</version>
    	<packaging>jar</packaging>
    	<name>TJWspringCloud-zookeeper</name>
    	<properties>
    		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    	
    	</properties>
    	
    	<dependencies>
    		<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>ch.qos.logback</groupId>  
                <artifactId>logback-core</artifactId>  
            </dependency>  
            <dependency>  
                <groupId>ch.qos.logback</groupId>  
                <artifactId>logback-classic</artifactId>  
            </dependency>  
            <dependency>  
                <groupId>ch.qos.logback</groupId>  
                <artifactId>logback-access</artifactId>  
            </dependency>  
    	
    	</dependencies>
    	<build>
    		<resources>
    			<resource>
    				<directory>src/main/java</directory>
    				<includes>
    					<include>**/*.xml</include>
    				</includes>
    			</resource>
    			<resource>
    				<directory>src/test/java</directory>
    				<includes>
    					<include>**/*.xml</include>
    				</includes>
    			</resource>
    			<resource>
    				<directory>src/main/resources</directory>
    				<includes>
    					<include>**/*.*</include>
    				</includes>
    			</resource>
    		</resources>
    		<plugins>  
    			<plugin>
    				<groupId>org.springframework.boot</groupId>
    				<artifactId>spring-boot-maven-plugin</artifactId>
    			</plugin>
    			
    	        <plugin>  
    	            <groupId>org.apache.maven.plugins</groupId>  
    	            <artifactId>maven-compiler-plugin</artifactId>  
    	            <version>2.0.2</version>  
    	            <configuration>  
    	                <source>1.8</source>  
    	                <target>1.8</target>  
    	            </configuration>  
    	        </plugin>  
    	    </plugins>  
    	</build>
    </project>

2、application.properties中添加自身及zk相关的配置

server.port=8833
    spring.application.name=spring-cloud-zookeeper-client
    spring.cloud.zookeeper.connectString=localhost:2181
    spring.cloud.zookeeper.discovery.instanceHost=localhost
    spring.cloud.zookeeper.discovery.instancePort=${server.port}

3、服务调用

在服务消费者通过服务名称来找到对应调用服务提供者的信息。

import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
    import org.springframework.cloud.client.discovery.DiscoveryClient;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.client.loadbalancer.LoadBalanced;
    import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.client.RestTemplate;
    
    @Configuration
    @EnableAutoConfiguration
    @EnableDiscoveryClient
    @RestController
    public class ZookeeperClientMain {
    
    	@Autowired
    	RestTemplate restTemplate;
    	
        @Bean
        @LoadBalanced
        public RestTemplate restTemplate() {
            return new RestTemplate();
        }
    
    	@RequestMapping(value = "/hi", method = RequestMethod.GET)
        public String add() {
            return restTemplate.getForEntity("http://spring-cloud-zookeeper/hi", String.class).getBody();
        }
    
      public static void main(String[] args) {
        SpringApplication.run(ZookeeperClientMain.class, args);
      }
    
    }

服务调用结果：

![70 1][]

总结：总体来说使用zk作为注册中心与其他注册中心（consul和eureka）类似，对于开发人员来说几乎可以不用在意注册中心到底是哪种类型，因为在服务进行调用的代码都是一致的。

[70]: /images/20220526/43970f91ab9a401c80c552f913b53888.png
[70 1]: /images/20220526/189fdde8024644929f31898fe3e0f93d.png