How to Dynamically Configure Routes in Spring Cloud Gateway with Zuul and Nacos

First, locate the routing code in the source.

1. Auto-configuration class: ZuulServerAutoConfiguration.java

This class contains the following code:

<code>@Bean
@ConditionalOnMissingBean(SimpleRouteLocator.class)
public SimpleRouteLocator simpleRouteLocator() {
    return new SimpleRouteLocator(this.server.getServlet().getContextPath(), this.zuulProperties);
}
</code>

RouteLocator is the routing locator. If the system does not provide one, the built‑in SimpleRouteLocator is used.

2. Next, examine SimpleRouteLocator.java, which includes the method:

<code>/**
 * Compute a map of path pattern to route. The default is just a static map from the
 * {@link ZuulProperties}, but subclasses can add dynamic calculations.
 * @return map of Zuul routes
 */
protected Map<String, ZuulRoute> locateRoutes() {
    LinkedHashMap<String, ZuulRoute> routesMap = new LinkedHashMap<>();
    for (ZuulRoute route : this.properties.getRoutes().values()) {
        routesMap.put(route.getPath(), route);
    }
    return routesMap;
}
</code>

This method assembles the route information configured in the configuration file. By overriding

locateRoutes

, you can load routes dynamically.

3. Create a custom route locator, e.g.,

CustomizeRouteLocator.java

(illustrated below).

4. Implement a concrete class that reads routing information from Nacos, the configuration center (illustrated below).

5. Define a custom bean to receive the route information stored in Nacos.

6. Add the necessary settings to

bootstrap.yml

:

<code>spring:
  application:
    name: cloud-gateway
---
spring:
  profiles:
    active:
      - dev
</code>

Here we configure the address of the Nacos service.

7. In Nacos, create a configuration file whose dataId follows the pattern

{spring.application.name}-{spring.profiles.active}.{fileExtension}

, for example:

After these steps, the dynamic routing configuration is complete.