springCloud Finchley 微服务架构从入门到精通【三】服务提供者/服务消费者(ribbon)

ゝ一世哀愁。 2023-10-17 20:15 18阅读 0赞

今天我们来学习 **服务消费者ribbon** 如何调用 **服务提供者**

\#\#一、新建一个 **获取用户信息** 的服务提供者\#\#

\#\#\#1、创建项目\#\#\#

由于 **获取用户信息** 属于业务模块，因此我们需要新建一个maven主项目：**bussnissservice**

![这里写图片描述][70]

**然后在该主项目上创建一个springboot项目**

![这里写图片描述][70 1]

**点击下一步，选择“Eureka Server”**

![这里写图片描述][70 2]

**此时的项目结构：**

![这里写图片描述][70 3]

\#\#\#2、代码实现\#\#\#

同样，将 **application.properties** 修改为 **bootstrap.yml**\*\* (以后不做特殊说明都修改为bootstrap.yml)\*\*

spring:
      application:
        name: service-user
    server:
      port: 8801

**使用@EnableEurekaClient注解开启Eureka客户端**

package com.mayi.springcloud;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    
    @SpringBootApplication
    @EnableEurekaClient
    public class BussnessserviceUserApplication {
        
    
    	public static void main(String[] args) {
        
    		SpringApplication.run(BussnessserviceUserApplication.class, args);
    	}
    }

**新建一个controller包，并在此包下写一个获取所有用户的接口**

import java.util.Map;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class UserManagementController {
        
    	
    	@Value("${server.port}")
    	String serverPort;
    	
    	@GetMapping("/listUsers")
    	public String ListUsers(){
        
    		
    		/**
    		 * 模拟从数据库查询
    		 */
    		List<Map<String, Object>> users = new ArrayList<Map<String, Object>>();
    		for(int i=1; i< 5; i++){
        
    			Map<String, Object> user = new HashMap<String, Object>();
    			user.put("id", i);
    			user.put("name", "小明" + i);
    			users.add(user);
    		}
    		return "服务器端口号：   " + serverPort + "   |   用户信息：   " + users.toString();
    	}
    }

\#\#\#3、测试：\#\#\#

**启动Eureka注册中心–启动 service-user 微服务–然后在浏览器输入**

http://localhost:8801/listUsers

![这里写图片描述][70 4]

端口号为8801的服务器为我们返回了用户列表信息

\#\#二、创建一个服务消费者ribbon\#\#

**ribbon** 是 **Netflix** 发布的 **客户端负载均衡** 组件，（nginx是服务端的负载均衡）

下面看一下具体实现

\#\#\#1、创建项目\#\#\#

![这里写图片描述][70 5]

**选择Eureka Server 和 Ribbon**

![这里写图片描述][70 6]  
**完整pom.xml如下：**

<?xml version="1.0" encoding="UTF-8"?>
    <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.mayi.springcloud</groupId>
    	<artifactId>bussnessservice-user-client-ribbon</artifactId>
    	<version>0.0.1-SNAPSHOT</version>
    	<packaging>jar</packaging>
    
    	<name>bussnessservice-user-client-ribbon</name>
    	<description>用户中心服务调用者ribbon</description>
    
    	<parent>
    		<groupId>org.springframework.boot</groupId>
    		<artifactId>spring-boot-starter-parent</artifactId>
    		<version>2.0.1.RELEASE</version>
    		<relativePath/> 
    	</parent>
    
    	<properties>
    		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    		<java.version>1.8</java.version>
    		<spring-cloud.version>Finchley.M9</spring-cloud.version>
    	</properties>
    
    	<dependencies>
    		<dependency>
    			<groupId>org.springframework.cloud</groupId>
    			<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework.cloud</groupId>
    			<artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
    		</dependency>
    
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-test</artifactId>
    			<scope>test</scope>
    		</dependency>
    	</dependencies>
    
    	<dependencyManagement>
    		<dependencies>
    			<dependency>
    				<groupId>org.springframework.cloud</groupId>
    				<artifactId>spring-cloud-dependencies</artifactId>
    				<version>${spring-cloud.version}</version>
    				<type>pom</type>
    				<scope>import</scope>
    			</dependency>
    		</dependencies>
    	</dependencyManagement>
    
    	<build>
    		<plugins>
    			<plugin>
    				<groupId>org.springframework.boot</groupId>
    				<artifactId>spring-boot-maven-plugin</artifactId>
    			</plugin>
    		</plugins>
    	</build>
    
    	<repositories>
    		<repository>
    			<id>spring-milestones</id>
    			<name>Spring Milestones</name>
    			<url>https://repo.spring.io/milestone</url>
    			<snapshots>
    				<enabled>false</enabled>
    			</snapshots>
    		</repository>
    	</repositories>
    
    
    </project>

\#\#\#2、代码实现\#\#\#

bootstrp.xml

spring:
      application:
        name: service-user-client-ribbon
    server:
      port: 8901

在启动类中\*\*@Bean\*\* 将 **restTemplate**注入到ioc容器, 并使用\*\*@LoadBalanced\*\* 注解声明开启 负载均衡

package com.mayi.springcloud;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.loadbalancer.LoadBalanced;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    import org.springframework.context.annotation.Bean;
    import org.springframework.web.client.RestTemplate;
    
    @SpringBootApplication
    @EnableEurekaClient
    public class BussnessserviceUserClientRibbonApplication {
    
    	public static void main(String[] args) {
    		SpringApplication.run(BussnessserviceUserClientRibbonApplication.class, args);
    	}
    	
    	@Bean
    	@LoadBalanced
    	RestTemplate restTemplate(){
    		return new RestTemplate();
    	}
    }

**接下来，新建一个client包，在该包下写一个ribbon接口**

package com.mayi.springcloud.client;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.client.RestTemplate;
    
    @RestController
    public class UserManagementRibbonClient {
        
    	
    	@Autowired
    	RestTemplate restTemplate;
    	
    	@GetMapping("/listUsersByRibbon")
    	public String ListUsersByRibbon(){
        
    		String result = this.restTemplate.getForObject("http://service-user/listUsers", String.class);
    		return result;
    	}
    }

说明：**service-user** 为服务名称， 一个服务名称对应多个**主机IP和端口号**，这样根据服务名调用就实现了负载均衡的功能

\#\#\#3、测试\#\#\#  
**为测试 ribbon负载均衡功能，我们再启动一个service-user服务，端口号为8802：**

![这里写图片描述][70 7]

访问：http://localhost:8901/listUsersByRibbon

因为默认的负载均衡算法是轮询，所以两台服务器轮流被调用，（也可自行修改负载均衡算法，例如：随机算法，只是简单的配置，这里不再阐述）

![这里写图片描述][70 8]

[70]: https://img-blog.csdn.net/20180427143553213?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3djYmxvZw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70
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[70 2]: https://img-blog.csdn.net/20180427143615950?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3djYmxvZw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70
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[70 8]: https://img-blog.csdn.net/20180427143747854?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3djYmxvZw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70