搭建springcloud的demo之Ribbon负载均衡基本配置(四)

****Spring Cloud Ribbon是基于Netfilx Ribbon实现的一套客户端的负载均衡的工具;

springcloud的负载均衡算法可以自定义;
集中式LB(偏硬件):即在服务的消费方和提供方之间使用的LB设施(可以是硬件,如F5,也可以是软件,如nginx)由该设施负责把访问请求通过某种策略发至服务的提供方;
进程内LB(偏软件):将LB逻辑集成到消费方,消费方从服务注册中心获知有哪些地址可用,然后自己再从这些地址中选择出一个合适的服务器;
Ribbon就属于进程内LB,她只是一个类库,继承于消费方进程,消费方通过它来获取到服务提供方的地址;

Ribbon的初步配置

修改microservicecloud-consumer-dept-80工程
修改pom.xml

<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>
  <parent>
    <groupId>com.yt.springcloud</groupId>
    <artifactId>microservicecloud</artifactId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>
  
  <artifactId>microservicecloud-consumer-dept-80</artifactId>
  <description>部门微服务消费者</description>
  
  <dependencies>
  
  	<dependency><!-- 自己定义的api -->
  		<groupId>com.yt.springcloud</groupId>
  		<artifactId>microservicecloud-api</artifactId>
  		<version>${project.version}</version>
  	</dependency>
  	
  	<dependency><!-- springboot-web -->
  		<groupId>org.springframework.boot</groupId>
  		<artifactId>spring-boot-starter-web</artifactId>
  	</dependency>
  	
  	 <!-- 修改后立即生效,热部署 (一修改,自动发布,自动构建)-->
  	<dependency>
  		<groupId>org.springframework</groupId>
  		<artifactId>springloaded</artifactId>
  	</dependency>
  	<dependency>
  		<groupId>org.springframework.boot</groupId>
  		<artifactId>spring-boot-devtools</artifactId>
  	</dependency>
  	
  		<!-- Ribbon相关 (eureka后面没有server的就是客户端,ribbon要跟eureka整合,类似于mysql和java的驱动包)-->
  	<dependency>
  		<groupId>org.springframework.cloud</groupId>
  		<artifactId>spring-cloud-starter-eureka</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-config</artifactId>
  	</dependency>
  	
  </dependencies>
  
  
  
</project> 

修改application.yml 追加eureka的服务注册地址

server :
   port: 80
   
   
eureka:
   client:
     register-with-eureka: false
     service-url:
       defaultZone: http//:eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/

对ConfigBean进行新注解@LoadBalanced 获得Rest时加入Ribbon的配置

package com.yt.springcloud.cfgbeans;

import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

@Configuration//其实就是ApplicationContext.xml
public class ConfigBean {
	
	/**
	 * RestTemplate提供了多种便捷访问远程Http服务的方法
	 * 是一种简单便捷的访问restful服务模板类,是Spring提供的用于访问Rest服务的客户端模板工具集
	 * @return
	 */
	@Bean
	@LoadBalanced//ribbon是客户端的负载均衡工具,所以在rest去访问微服务的时候,自带负载均衡,这个注解是开启ribbon负载均衡的
	public RestTemplate getRestTemplate() {
		return new RestTemplate();
	}

}

主启动类DeptConsumer80_App添加@EnableEurekaClient

package com.yt.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableEurekaClient
public class DeptConsumer80_App {
	
	public static void main(String[] args) {
		SpringApplication.run(DeptConsumer80_App.class, args);
	}

}

修改DeptController_Consumer客户端访问类

package com.yt.springcloud.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import com.yt.springcloud.entity.Dept;

@RestController
public class DeptController_consumer {
	
	//private static final String REST_URL_PREFIX="http://localhost:8001";
	private static final String REST_URL_PREFIX="http://MICROSERVICECLOUD-DEPT";//改成微服务的服务名称
	
	/**
	 * 使用RestTemplate访问restful接口非常的简单粗暴无脑
	 * (url,requestMap,ResponseBean.class)这三个参数分别代表
	 * REST请求地址,请求参数,HTTP响应转换被转换成的对象类型
	 */
	@Autowired
	private RestTemplate restTemplate;
	
	@RequestMapping(value="/consumer/dept/add")
	public boolean add(Dept dept) {
		return restTemplate.postForObject(REST_URL_PREFIX+"/dept/add", dept, boolean.class);
	}
	
	@RequestMapping(value="/consumer/dept/get/{id}")
	public Dept get(@PathVariable("id") Long id) {
		return restTemplate.getForObject(REST_URL_PREFIX+"/dept/get/"+id, Dept.class);
	}
	
	@SuppressWarnings("unchecked")
	@RequestMapping(value="/consumer/dept/list")
	public List<Dept> list(Dept dept) {
		return restTemplate.getForObject(REST_URL_PREFIX+"/dept/list", List.class);
	}
	
	@RequestMapping(value="/consumer/dept/discovery")
	public Object discovery(Dept dept) {
		return restTemplate.getForObject(REST_URL_PREFIX+"/dept/discovery", Object.class);
	}

}
 

先启动3个eureka集群后,再启动micros-provider-dept-8001并注册进eureka
启动microservicecloud-consumer-dept-80
自测:http://localhost/consumer/dept/get/1