SpringCloud之Zuul(路由网关)

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。

Authentication
Insights
Stress Testing
Canary Testing
Dynamic Routing
Service Migration
Load Shedding
Security
Static Response handling
Active/Active traffic management

新建一个project为zuul_demo

<!--因为是eureka的注册中心所以需要引入一个客户端的依赖-->
      <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
<!--zuul主要依赖-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
        </dependency>

修改启动类

package com.tg.servicezuul;

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;

@SpringBootApplication
@EnableEurekaClient//开启一个eureka的客户端
@EnableZuulProxy  //开启zuulProxy
public class ServiceZuulApplication {

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

#1.给这个应用服务起名字spring:
spring:
  application:
    name: server-zuul
server:
  port: 8766
zuul:
  routes:
    api-a:        #api-a 这个是自定义的   serviceId对应注册中心的服务 这里的配置解释：通过  
                   #localhost:8766/api-a/**访问 交由  Eureka-RIBBON 去处理            
                 #localhost:8766/api-b/**访问 交由  SERVICE-FEIGN 去处理
      path: /api-a/**
      serviceId: EUREKA-RIBBON
    api-b:
      path: /api-b/**
      serviceId: SERVICE-FEIGN
eureka:
  client:
    service-url:
      defaultZone:  http://localhost:8761/eureka/eureka

启动服务端 客户端 启动 ribbon 和 feign
采用浏览器访问

借用大佬的api网段地址 大家有兴趣可以去看一下

自定义过滤

package com.tg.servicezuul;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;

//不打上注解是扫描不到的
@Component
public class MyZuulFilter extends ZuulFilter {
    private static Logger log = LoggerFactory.getLogger(MyZuulFilter.class);

    //返回值可以为 pre路由之前  post路由之后  error发送错误时候处理 route时候处理
    //分别对应的class大家可以去看一下
    //DebugFilter SendResponseFilter  SendErrorFilter RibbonRoutingFilter
    @Override
    public String filterType() {
        return "pre";
    }

    //过滤的顺序 可以理解 多个过滤器排序
    @Override
    public int filterOrder() {
        return 0;
    }

    //false 是否过滤  true 永久过滤
    @Override
    public boolean shouldFilter() {
        return true;
    }

    //执行的方法
    @Override
    public Object run() throws ZuulException {
        RequestContext ctx = RequestContext.getCurrentContext();
        HttpServletRequest request = ctx.getRequest();
        Object accessToken = request.getParameter( "token" );
        if (accessToken == null) {
            ctx.setSendZuulResponse( false );
            ctx.setResponseStatusCode( 401 );
            try {
                ctx.getResponse().getWriter().write( "token is empty" );
            } catch (Exception e) {
            }

            return null;
        }
        return null;
    }
}

Zuul文档