SpringCloud之Ribbon

爱被打了一巴掌 2022-04-16 04:06 212阅读 0赞

[附：SpringCloud之系列汇总跳转地址][SpringCloud]

### Ribbon简介 ###

Spring Cloud Ribbon 是基于 Netflix Ribbon 实现的一套客户端负载均衡工具，其主要功能是提供客户端的软件负载均衡算法，将 Netflix 的中间层服务连接在一起。Ribbon 提供多种负载均衡策略：如轮询、随机、响应时间加权等。

Spring cloud有两种服务调用方式，一种是ribbon+restTemplate，另一种是feign（Feign默认集成了ribbon）。在这一篇文章首先介绍ribbon+restTemplate。

### Ribbon实践 ###

在上一篇的基础上，新建一个Ribbon的maven子项目，项目结构

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0MzEzNjM1_size_16_color_FFFFFF_t_70][]

pom.xml（添加 spring-cloud-starter-eureka包时，会自动添加 Ribbon 依赖包。）

<?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.yj</groupId>
    		<artifactId>SpringCloud</artifactId>
    		<version>0.0.1-SNAPSHOT</version>
    	</parent>
    	
    	<artifactId>Ribbon</artifactId>
    	<name>Ribbon</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-eureka</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-web</artifactId>
    		</dependency>
    	</dependencies>
    	
    	<build>
    		<finalName>${artifactId}</finalName>
    		<plugins>
    			<plugin>
    				<groupId>org.springframework.boot</groupId>
    				<artifactId>spring-boot-maven-plugin</artifactId>
    				<configuration>
    					<skip>true</skip>
    				</configuration>
    			</plugin>
    			<plugin>
    				<groupId>org.apache.maven.plugins</groupId>
    				<artifactId>maven-jar-plugin</artifactId>
    				<configuration>
    
    					<archive>
    						<manifest>
    							<mainClass>com.yj.ribbon.RibbonApplication</mainClass>
    							<addClasspath>true</addClasspath>
    							<classpathPrefix>lib</classpathPrefix>
    						</manifest>
    						<manifestEntries>
    							<Class-Path>./</Class-Path>
    						</manifestEntries>
    					</archive>
    					<excludes>
    						<exclude>config/**</exclude>
    						<exclude>**.xml</exclude>
    						<exclude>**.properties</exclude>
    					</excludes>
    				</configuration>
    			</plugin>
    			<plugin>
    				<artifactId>maven-assembly-plugin</artifactId>
    				<configuration>
    					<appendAssemblyId>false</appendAssemblyId>
    					<descriptors>
    						<descriptor>src/main/build/package.xml</descriptor>
    					</descriptors>
    				</configuration>
    				<executions>
    					<execution>
    						<id>make-assembly</id>
    						<phase>package</phase>
    						<goals>
    							<goal>single</goal>
    						</goals>
    					</execution>
    				</executions>
    			</plugin>
    		</plugins>
    		<testResources>
    			<testResource>
    				<directory>src/main/resources</directory>
    			</testResource>
    		</testResources>
    	</build>
    </project>

RibbonController

package com.yj.ribbon.controller;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    import com.yj.ribbon.service.RibbonService;
    
    @RestController
    public class RibbonController {
    
    	@Autowired
    	private RibbonService ribbonService;
    
    	@GetMapping(value = "/hiRibbon")
    	public String hiRibbon(@RequestParam(name="name") String name) {
    		return ribbonService.hiRibbon(name);
    	}
    }

RibbonService

package com.yj.ribbon.service;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.web.client.RestTemplate;
    
    @Service
    public class RibbonService {
    
    	@Autowired
    	private RestTemplate restTemplate;
    
    	public String hiRibbon(String name) {
    		return restTemplate.getForObject("http://eureka-client/hiEureka?name=" + name, String.class);
    	}
    }

④application.properties

server.port=8005
    
    spring.application.name=ribbon
    eureka.client.serviceUrl.defaultZone=http://admin:123456@192.168.37.139:8001/eureka,http://admin:123456@192.168.37.139:8002/eureka
    eureka.instance.prefer-ip-address=true
    eureka.instance.instance-id=${spring.cloud.client.ipAddress}:${server.port}
    eureka.instance.hostname=${spring.cloud.client.ipAddress}

application.properties

⑧RibbonApplication（@LoadBalanced注解让restTemplate可以很容易的通过ribbon实现客户端的负载均衡功能）

package com.yj.ribbon;
    
    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 RibbonApplication {
    	public static void main(String[] args) {
    		SpringApplication.run(RibbonApplication.class, args);
    	}
    	
        @Bean
        @LoadBalanced
        RestTemplate restTemplate() {
            return new RestTemplate();
        }
    }

部署启动，Ribbon项目也被注册到Eureka上面了

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0MzEzNjM1_size_16_color_FFFFFF_t_70 1][]

访问[http://192.168.37.139:8005/hiRibbon?name=yj，交替显示][http_192.168.37.139_8005_hiRibbon_name_yj]hi yj ,i am from port:8003，hi yj ,i am from port:8004

以上的流程可以总结为：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0MzEzNjM1_size_16_color_FFFFFF_t_70 2][]

[附：SpringCloud之系列汇总跳转地址][SpringCloud]

[SpringCloud]: https://blog.csdn.net/qq_24313635/article/details/104061217
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0MzEzNjM1_size_16_color_FFFFFF_t_70 1]: /images/20220416/23f2d39602a9463189c63b31e3aad3b6.png
[http_192.168.37.139_8005_hiRibbon_name_yj]: http://192.168.37.139:8005/hiRibbon?name=yj
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI0MzEzNjM1_size_16_color_FFFFFF_t_70 2]: /images/20220416/8d467d1aef024a6c9d06084f2840941f.png