是否可以基于 Spring 云网关中的路径进行路由？

Question

my problem is the following: I need to set up gateway to route depending on the incoming path, for example: http://whatever.com/get/abcd:efgh:jklm:nopq-1234-5678-90ab should direct to http://service.com/service5 because the number following the second to last dash is a 5. Accordingly, http://whatever.com/get/abcd:efgh:jklm:nopq-1234-8678-90ab should direct to http://service.com/service8 because the number following the second to last dash is an 8. The preceding abcd:efgh: etc is not static so it can be anything, but it does have a format with exact number of semicolons and dashes, so a regex could do the trick, I guess. However, I could not find anything in Path route predicate. (I could do fine with Query as it accepts REGEX, but in this special case I need to route depending on the path).

Is this possible at all? Thank you in advance!

Answer 1

You can create a RoutLocator bean and define your destination route based on your incoming route path. See if this helps https://www.baeldung.com/spring-cloud-gateway#routing-handler

Answer 2

Create your CustomRoutePredicateFactory class

public class CustomRoutePredicateFactory extends AbstractRoutePredicateFactory<CustomRoutePredicateFactory.Config> {

    public CustomRoutePredicateFactory(Class<Config> configClass) {
        super(configClass);
    }

    public Predicate<ServerWebExchange> apply(Config config) {
        return (ServerWebExchange t) -> {
            boolean result = false;

            int pathServerId = 0; // logic to extract server id from request URL
            if(config.getServerId() == pathServerId) {
                result= true;
            }
            return result;
        };
    }

    public static class Config {
        private int serverId;
        public Config(int serverId) {
            this.serverId = serverId;
        }
        public int getServerId() {
            return this.serverId;
        }
    }
}

Apply your Predicate Factory twice (for 5 and 8 each) in RouteLocatorBuilder (programatically or in configuration). Sample below for programatically

       .route(p -> p
             .predicate(customRoutePredicateFactory.apply(
                   new CustomRoutePredicateFactory.Config(5)))
             .uri("lb://service5")
       )

Have fun. Enjoy Coding.