Spring Cloud微服务网关Zuul动态路由配置优化和手动触发路由刷新

妖狐艹你老母 2024-03-23 11:02 73阅读 0赞

## 二、DynamicZuulRouteLocator小优化 ##

在之前的文章中提到，`HeartbeatEvent`事件会频繁触发，每次都需要去查询数据库。而且`ZuulRefreshListener`监听的其余四个刷新事件也不会经常触发。所以这里就可以做一下小优化，因为系统上线稳定后，路由一般是不会经常变动的。所以我们可以把路由规则配置给缓存起来，这样就不会每次的心跳都去查询数据库。

这里有分两种情况：

*  单机Zuul网关下的本地缓存
 *  Zuul网关集群下的分布式缓存

### 2.1 本地缓存 ###

直接上代码：

public class DynamicZuulRouteLocator extends SimpleRouteLocator implements RefreshableRouteLocator {
    
        private final ZuulProperties zuulProperties;
    
        private final RoutingRuleService routingRuleService;
    
        private static final ConcurrentHashMap<String, ZuulRoute> routesCache = new ConcurrentHashMap<>();
    
        public DynamicZuulRouteLocator(String servletPath, ZuulProperties properties, RoutingRuleService routingRuleService) {
            super(servletPath, properties);
            this.zuulProperties = properties;
            this.routingRuleService = routingRuleService;
        }
    
        @Override
        public void refresh() {
            doRefresh();
        }
    
        @Override
        protected Map<String, ZuulProperties.ZuulRoute> locateRoutes() {
            Map<String, ZuulProperties.ZuulRoute> allRoutes = null;
            if (routesCache.isEmpty()) {
                allRoutes = routingRuleService.findAllRoutes();
                routesCache.putAll(allRoutes);
            } else {
                allRoutes = routesCache;
            }
            LinkedHashMap<String, ZuulProperties.ZuulRoute> routesMap = new LinkedHashMap<>();
            // 父类的 SimpleRouteLocator的locateRoutes()读取的是配置文件中的路由规则配置
            routesMap.putAll(super.locateRoutes());
            routesMap.putAll(allRoutes);
            LinkedHashMap<String, ZuulProperties.ZuulRoute> values = new LinkedHashMap<>();
            routesMap.forEach((key, value) -> {
                String path = key;
                if (!path.startsWith("/")) {
                    path = "/" + path;
                }
                if (StringUtils.hasText(this.zuulProperties.getPrefix())) {
                    path = this.zuulProperties.getPrefix() + path;
                    if (!path.startsWith("/")) {
                        path = "/" + path;
                    }
                }
                values.put(path, value);
            });
            return values;
        }
    
        public static void clearCache() {
            routesCache.clear();
        }
    }
    复制代码

这是简单地使用了`ConcurrentHashMap`作为本地缓存。当然也可以使用`caffeine`、`Guava Cache`、`Ehcache`等本地缓存框架。使用`ConcurrentHashMap`主要是更加方便快捷，