springboot zuul 动态路由的实现

之前文章讲过zuul使用的filter进行路由等信息配置

PreDecorationFilter 进行路由查找，他依托RouteLocator进行查找

Spring Cloud默认的路由定位器由SimpleRouteLocator来实现

SimpleRouteLocator代码如下

@Override
public Route getMatchingRoute(final String path) {

   return getSimpleMatchingRoute(path);

}

protected Route getSimpleMatchingRoute(final String path) {
   if (log.isDebugEnabled()) {
      log.debug("Finding route for path: " + path);
   }

   // This is called for the initialization done in getRoutesMap()
   getRoutesMap();

   if (log.isDebugEnabled()) {
      log.debug("servletPath=" + this.dispatcherServletPath);
      log.debug("zuulServletPath=" + this.zuulServletPath);
      log.debug("RequestUtils.isDispatcherServletRequest()="
            + RequestUtils.isDispatcherServletRequest());
      log.debug("RequestUtils.isZuulServletRequest()="
            + RequestUtils.isZuulServletRequest());
   }

   String adjustedPath = adjustPath(path);

   ZuulRoute route = getZuulRoute(adjustedPath);

   return getRoute(route, adjustedPath);
}

protected Map getRoutesMap() {
   if (this.routes.get() == null) {
      this.routes.set(locateRoutes());
   }
   return this.routes.get();
}

protected Map locateRoutes() {
   LinkedHashMap routesMap = new LinkedHashMap<>();
   for (ZuulRoute route : this.properties.getRoutes().values()) {
      routesMap.put(route.getPath(), route);
   }
   return routesMap;
}

使用继承这默认的SimpleRouteLocator  实现protected方法locateRoutes ，可以改成从数据库里面查询，也可以改成zk查询

 

路由动态刷新

org.springframework.cloud.netflix.zuul.filters.SimpleRouteLocator#doRefresh  zuul的路由刷新是通过该方法刷新的

 

zuul内部提供了ZuulRefreshListener，它会监听ApplicationEventPublisher发布的事件，如果事件为RoutesRefreshedEvent，则会调用routeLocator的refresh函数，

然后在自定义的路由定位器中可以直接调用SimpleRouteLocator的doRefresh函数