Zuul的应用

一、介绍

注：Zuul中默认就已经集成了Ribbon负载均衡和Hystix熔断机制。但是所有的超时策略都是走的默认值，比如熔断超时时间只有1S，很容易就触发了。

二、依赖

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-netflix-zuul</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

三、配置

单一配置：
zuul:
  prefix: /api  #前缀
  retryable: true
  routes:
    user-service: # 这里是路由id，随意写
      path: /user-service/** # 这里是映射路径
      url: http://127.0.0.1:8081 # 映射路径对应的实际url地址 

动态路由：
zuul:
  routes:
    user-service: # 这里是路由id，随意写
      path: /user-service/** # 这里是映射路径
      serviceId: user-service # 指定服务名称 

简化配置：
zuul:
  routes:
    user-service: /user-service/** # 这里是映射路径 

综合配置：
zuul:
  retryable: true
ribbon:
  ConnectTimeout: 250 # 连接超时时间(ms)
  ReadTimeout: 2000 # 通信超时时间(ms)
  OkToRetryOnAllOperations: true # 是否对所有操作重试
  MaxAutoRetriesNextServer: 2 # 同一服务不同实例的重试次数
  MaxAutoRetries: 1 # 同一实例的重试次数
hystrix:
  command:
      default:
        execution:
          isolation:
            thread:
              timeoutInMillisecond: 6000 # 熔断超时时长：6000ms

 四、过滤器

参考：https://blog.csdn.net/wo18237095579/article/details/83543592

@Component
@EnableConfigurationProperties({JwtProperties.class, FilterProperties.class})
public class AuthFilter extends ZuulFilter{

    @Autowired
    private JwtProperties prop;
    @Autowired
    private FilterProperties filterProp;

    @Override
    public String filterType() {
        return FilterConstants.PRE_TYPE;
    }

    @Override
    public int filterOrder() {
        return FilterConstants.PRE_DECORATION_FILTER_ORDER-1;
    }

    @Override
    public boolean shouldFilter() {
        RequestContext ctx=RequestContext.getCurrentContext();
        HttpServletRequest request=ctx.getRequest();
        String path=request.getRequestURI();
        boolean isAllowPath=isAllowPath(path);
        return !isAllowPath;
    }

    public boolean isAllowPath(String path){
        for(String allowPath:filterProp.getAllowPaths()){
            if(path.startsWith(allowPath)) {
                return true;
            }
        }
        return false;
    }

    @Override
    public Object run() throws ZuulException {
        RequestContext ctx=RequestContext.getCurrentContext();
        HttpServletRequest request=ctx.getRequest();
        String token= CookieUtils.getCookieValue(request,prop.getCookieName());

        try {
            UserInfo user= JwtUtils.getUserInfo(prop.getPublicKey(),token);
        } catch (Exception e) {
            ctx.setSendZuulResponse(false);
            ctx.setResponseStatusCode(403);
        }
        return null;
    }
}