spring cloud 2.x版本 Zuul路由网关教程

前言

本文采用Spring cloud本文为2.1.8RELEASE，version=Greenwich.SR3

本文基于前两篇文章eureka-server、eureka-client、eureka-ribbon和eureka-feign的实现。
参考

eureka-server

eureka-client

eureka-ribbon

eureka-feign

概念

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，例如将请求/api/goods转发到商品服务上、/api/order转发到订单服务上等。

Zull默认和Ribbon结合实现了负载均衡功能。

创建Zuul工程

1.1 创建sping boot工程：eureka-zuul

1.2 添加pom.xml相关依赖

<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
</dependency>

1.3 application添加配置信息

spring:
  application:
    name: eureka-zuul
server:
  port: 8400

eureka:
  instance:
    hostname: localhost
    lease-renewal-interval-in-seconds: 5
    lease-expiration-duration-in-seconds: 10
  client:
    service-url:
      defaultZone: http://eureka1.server.com:8701/eureka/,http://eureka2.server.com:8702/eureka/,http://eureka3.server.com:8703/eureka/

zuul:
  routes:
    eureka-ribbon: #对应服务名称,可以自定义（最好保持一致）
      path: /ribbon/*
      serviceId: eureka-ribbon #对应服务名称
    eureka-feign:
      path: /eureka-feign/*
      serviceId: eureka-feign #对应服务名称

1.4 启动类EurekaZuulApplication增加注解

package spring.cloud.demo.eurekazuul;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;

@EnableZuulProxy
@SpringBootApplication
public class EurekaZuulApplication {

    public static void main(String[] args) {
        SpringApplication.run(EurekaZuulApplication.class, args);
    }

}

@EnableZuulProxy:开启Zuul网关注解

1.5 启动eureka-zuul服务

打开浏览器，分别输入http://localhost:8400/ribbon/sayHello,http://localhost:8400/eureka-feign/feign/sayHello,显示结果分别如下：

可以看到Zuul按照路由转发的配置规则，把/ribbon/的请求转发到eureka-ribbon服务上，把/eureka-feign/的请求转发到eureka-feign的服务上。

至此，一个简单基于Zuul路由网关就搭建完成了。

彩蛋

添加自定义过滤器

Zuul过滤器有四种类型分别是

pre 路由前

route 路由时

post 路由完毕

error 发生错误时

创建自定义过滤器filter

package spring.cloud.demo.eurekazuul.fillter;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import org.apache.commons.lang.StringUtils;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 简单filter过滤器
 * @auther: maomao
 * @DateT: 2019-09-17
 */
public class CommonFilter extends ZuulFilter {

    /**
     * 在请求被路由之前调用
     * @return
     */
    @Override
    public String filterType() {
        return "pre";
    }

    /**
     * filter执行顺序，通过数字指定 ,优先级为0，数字越大，优先级越低
     * @return
     */
    @Override
    public int filterOrder() {
        return 0;
    }

    /**
     * 是否执行该过滤器，此处为true，说明需要过滤
     * @return
     */
    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() throws ZuulException {
        RequestContext requestContext = RequestContext.getCurrentContext();
        HttpServletRequest request = requestContext.getRequest();

        //获取请求参数
        String token = request.getParameter("token");

        //校验token是否可以通过
        if (StringUtils.isNotBlank(token) && token.equals("maomao")) {
            requestContext.setSendZuulResponse(true);
            requestContext.setResponseStatusCode(200);
            requestContext.set("code", 1);
        } else {
            requestContext.setSendZuulResponse(false);
            requestContext.setResponseStatusCode(401);
            HttpServletResponse response = requestContext.getResponse();
            response.setHeader("content-type", "text/html;charset=utf-8");
            requestContext.setResponseBody("网关认证失败，停止路由");
            requestContext.set("code", 0);
        }
        return null;
    }
}

将过滤器加入Bean，增加Config类

package spring.cloud.demo.eurekazuul.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import spring.cloud.demo.eurekazuul.fillter.CommonFilter;

/**
 * @auther: maomao
 * @DateT: 2019-09-17
 */
@Configuration
public class ZuulFilterConfig {

    @Bean
    public CommonFilter commonFilter() {
        return new CommonFilter();
    }
}