玩转SpringCloud（F版本）四．路由网关(zuul)

<parent>
   <groupId>com.fsdmgroupId>
   <artifactId>SpringCloud_test1artifactId>
   <version>1.0-SNAPSHOTversion>
parent>

<dependencies>
   <dependency>
      <groupId>org.springframework.cloudgroupId>
      <artifactId>spring-cloud-starter-netflix-eureka-clientartifactId>
   dependency>
   <dependency>
      <groupId>org.springframework.bootgroupId>
      <artifactId>spring-boot-starter-webartifactId>
   dependency>
   <dependency>
      <groupId>org.springframework.cloudgroupId>
      <artifactId>spring-cloud-starter-netflix-zuulartifactId>
   dependency>

dependencies>

@SpringBootApplication
@EnableZuulProxy
@EnableEurekaClient
@EnableDiscoveryClient
public class Demo5Application {

   public static void main(String[] args) {
      SpringApplication.run(Demo5Application.class, args);
   }
}

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
server:
  port: 8766
spring:
  application:
    name: service-zuul
zuul:
  routes:
    api-a:
      path: /api-a/**
      serviceId: service-ribbon
    api-b:
      path: /api-b/**
      serviceId: service-feign

@Component
public class MyFilter extends ZuulFilter {

    /**
     * filterType：返回一个字符串代表过滤器的类型，在zuul中定义了四种不同生命周期的过滤器类型，具体如下：
     * pre：路由之前
     * routing：路由之时
     * post： 路由之后
     * error：发送错误调用
     */
    @Override
    public String filterType() {
        return "pre";
    }

    //过滤的顺序
    @Override
    public int filterOrder() {
        return 0;
    }

    //这里可以写逻辑判断，是否要过滤，本文true,永远过滤。
    @Override
    public boolean shouldFilter() {
        return true;
    }
    //过滤器的具体逻辑。可用很复杂，包括查sql，nosql去判断该请求到底有没有权限访问。
    @Override
    public Object run() throws ZuulException {
        System.out.println("==============================================================");
        RequestContext ctx = RequestContext.getCurrentContext();
        HttpServletRequest request = ctx.getRequest();
        System.out.println(String.format("%s >>> %s", request.getMethod(), request.getRequestURL().toString()));
        Object accessToken = request.getParameter("token");
        if(accessToken == null) {
            System.out.println("token is empty");
            ctx.setSendZuulResponse(false);
            ctx.setResponseStatusCode(401);
            try {
                ctx.getResponse().getWriter().write("token is empty");
            }catch (Exception e){}

            return null;
        }
        System.out.println("ok");
        return null;
    }
}