Springcloud （4）Zuul中的过滤器-CFANZ编程社区

1.导入依赖信息，由于Zuul是依赖于feign和hystrix的，所以需要把相应的包导入

<!--添加Eureka客户端依赖-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

<!--Feign声明式服务调用-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-feign</artifactId>
    <version>1.4.0.RELEASE</version>
</dependency>

<!--hystrix-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-hystrix</artifactId>
    <version>1.4.0.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-hystrix-dashboard</artifactId>
    <version>1.4.0.RELEASE</version>
</dependency>

<!--整合zuul-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
</dependency>

2. 在主程序中添加@EnableZuulProxy注解

@SpringBootApplication
@EnableZuulProxy
@EnableEurekaClient
public class ServerGatewayApplication {

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

zuul中有四种过滤器：pre，route，error，post 。

filterType()：方法的返回值就是用来执行上面的四种之一。

filterOrder():过滤器的排序，自定义过滤器执行的顺序，数值越大越靠后执行，越小就越先执行

shouldFilter():用于控制当前filter是否执行

run():filter的逻辑

package com.ooyhao.cloud.servergateway.filter;

import com.google.gson.Gson;
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import com.ooyhao.cloud.servergateway.api.ApiResult;
import com.ooyhao.cloud.servergateway.exception.NoAccountException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.netflix.zuul.filters.support.FilterConstants;
import org.springframework.stereotype.Component;

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

/**
 * @ClassName LoginFilter
 * @Author ouYang
 * @Date 2019/4/29 23:13
 * @Description 描述这个类的作用
 * @Version 2.0
 */
@Component
public class LoginFilter extends ZuulFilter {

    private Logger logger = LoggerFactory.getLogger(LoginFilter.class);

    //四种类型：pre,routing,error,post
    //pre:       主要用在路由映射的阶段是寻找路由映射表的
    //routing:   具体的路由转发过滤器是在routing路由器，具体的请求转发的时候会调用
    //error:     一旦前面的过滤器出错了，会调用error过滤器。
    //post:      当routing，error运行完后才会调用该过滤器，是在最后阶段的
    @Override
    public String filterType() {
        return FilterConstants.PRE_TYPE;
    }

    //自定义过滤器执行的顺序，数值越大越靠后执行，越小就越先执行
    @Override
    public int filterOrder() {
        return -1;
    }

    //控制过滤器生效不生效，可以在里面写一串逻辑来控制
    //是否执行该过滤器，true代表需要过滤
    @Override
    public boolean shouldFilter() {
        //获取Request对象
        HttpServletRequest request = RequestContext.getCurrentContext().getRequest();
        String token = request.getParameter("token");
        logger.info("----------< token:{} >----------",token);
        if (token.equals("123456")){
            return false;
        }
        return true;
    }

    //执行过滤逻辑
    @Override
    public Object run() throws ZuulException {
        RequestContext context = RequestContext.getCurrentContext();
        HttpServletResponse response = RequestContext.getCurrentContext().getResponse();
        try {
            System.out.println("认证过滤器");
            int i = 1/0;

        }catch (Exception e){
            System.out.println("e:"+e);
            context.setSendZuulResponse(false);//表示不再调用相应的服务
            context.setResponseStatusCode(400);//返回浏览器的状态码
            ApiResult apiResult = new ApiResult();
            apiResult.setCode(403);
            apiResult.setMessage("用户名不存在");
            apiResult.setSuccess(false);
            apiResult.setObj("account no found");
            Gson gson = new Gson();
            String json = gson.toJson(apiResult);
            response.setCharacterEncoding("utf8");
            response.setContentType("application/json;charset=UTF-8");//设置UTF8并以json格式返回
            context.setResponseBody(json);
//            throw new NoAccountException(e,"account no found",403,"用户名不存在");
//            return null;
        }
        return null;
    }
}