1、使用ribbon实现负载均衡
ribbon是一个负载均衡客户端 类似nginx反向代理，可以很好的控制htt和tcp的一些行为。Feign默认集成了ribbon。
启动两个会员服务工程，端口号分别为8762、8763，订单服务使用负载均衡策略轮训到会员服务接口。
在上一篇SpringCloud微服务基础上修改Service_Menber项目代码区分端口项目
package com.zhang.controller; import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; import java.util.ArrayList;
import java.util.List; @RestController
public class MemberController { @Value("${server.port}")
private String serverPort; @RequestMapping("/getMemberAll")
public List<String> getUserList() {
List<String> listUser = new ArrayList<String>();
listUser.add("zhangsan");
listUser.add("lisi");
listUser.add("zhang");
listUser.add("端口号:"+serverPort);
return listUser;
} }
将Service_Menber项目复制一份，名为Service_Menber负载均衡，端口改为8763。分别启动Eureka、Service_Menber、Service_Menber负载均衡、Service_Order，然后访问http://127.0.0.1:8764/getOrderUserAll，第一次出现8762 第二次出现8763。依次轮询，说明负载均衡配置成功。
2、路由网关(zuul)
Zuul的主要功能是路由转发和过滤器。路由功能是微服务的一部分，比如／api/user转发到到user服务，/api/shop转发到到shop服务。zuul默认和Ribbon结合实现了负载均衡的功能， 类似于nginx转发。
创建Service_Zuul项目
添加配置：
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8888/eureka/
server:
port: 8769
spring:
application:
name: service-zuul
zuul:
routes:
api-a:
path: /api-member/**
service-id: service-member #访问 http://127.0.0.1:8769/api-member/getMemberAll ==》http://127.0.0.1:8762/getMemberAll
api-b:
path: /api-order/**
service-id: service-order #访问 http://127.0.0.1:8769/api-order/getOrderUserAll ==》http://127.0.0.1:8764/getOrderUserAll
添加依赖：
<?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.zhang</groupId>
<artifactId>zuul</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>zuul</name>
<description>Demo project for Spring Boot</description> <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.2.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</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.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-zuul</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies> <dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Dalston.RC1</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>
添加Java代码
package com.zhang; import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy; @EnableZuulProxy
@EnableEurekaClient
@SpringBootApplication
public class ZullApplication { public static void main(String[] args) {
SpringApplication.run(ZullApplication.class, args);
} }
package com.zhang; import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component; import javax.servlet.http.HttpServletRequest; @Component
public class MyFilter extends ZuulFilter { private static Logger log = LoggerFactory.getLogger(MyFilter.class); public String filterType() {
return "pre";
} public int filterOrder() {
return 0;
} public boolean shouldFilter() {
return true;
} public Object run() {
RequestContext ctx = RequestContext.getCurrentContext();
HttpServletRequest request = ctx.getRequest();
log.info(String.format("%s >>> %s", request.getMethod(), request.getRequestURL().toString()));
Object accessToken = request.getParameter("token");
String refer=request.getHeader("refer"); if (accessToken != null) {
return null;
}
log.warn("token is empty");
ctx.setSendZuulResponse(false);
ctx.setResponseStatusCode(401);
try {
ctx.getResponse().getWriter().write("token is empty");
} catch (Exception e) {
}
return null; }
}
启动项目 访问http://127.0.0.1:8769/api-member/getMemberAll?token=zhang 相当于访问http://127.0.0.1:8762/getMemberAll
访问http://127.0.0.1:8769/api-order/getOrderUserAll?token=oo 相当于访问http://127.0.0.1:8764/getOrderUserAll