Calls to filter(collection) will now transform non-Ordered filters to Ordered filters.

fixes gh-445

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/route/builder/GatewayFilterSpec.java

@@ -20,12 +20,18 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.util.Collection;
+import java.util.List;
 import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import reactor.retry.Repeat;
+import reactor.retry.Retry;
+
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.cloud.gateway.filter.GatewayFilter;
 import org.springframework.cloud.gateway.filter.OrderedGatewayFilter;
@@ -59,9 +65,6 @@ import org.springframework.core.Ordered;
 import org.springframework.http.HttpStatus;
 import org.springframework.web.server.ServerWebExchange;
 
-import reactor.retry.Repeat;
-import reactor.retry.Retry;
-
 /**
  * Applies specific filters to routes.
  */
@@ -109,17 +112,30 @@ public class GatewayFilterSpec extends UriSpec {
 	 * @return a {@link GatewayFilterSpec} that can be used to apply additional filters
 	 */
 	public GatewayFilterSpec filters(GatewayFilter... gatewayFilters) {
-		this.routeBuilder.filters(gatewayFilters);
+		List<GatewayFilter> filters = transformToOrderedFilters(Stream.of(gatewayFilters));
+		this.routeBuilder.filters(filters);
 		return this;
 	}
 
+	public List<GatewayFilter> transformToOrderedFilters(Stream<GatewayFilter> stream) {
+		return stream
+				.map(filter -> {
+					if (filter instanceof Ordered) {
+						return filter;
+					} else {
+						return new OrderedGatewayFilter(filter, 0);
+					}
+				}).collect(Collectors.toList());
+	}
+
 	/**
 	 * Applies the list of filters to the route.
 	 * @param gatewayFilters the filters to apply
 	 * @return a {@link GatewayFilterSpec} that can be used to apply additional filters
 	 */
 	public GatewayFilterSpec filters(Collection<GatewayFilter> gatewayFilters) {
-		this.routeBuilder.filters(gatewayFilters);
+		List<GatewayFilter> filters = transformToOrderedFilters(gatewayFilters.stream());
+		this.routeBuilder.filters(filters);
 		return this;
 	}
 

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/route/builder/GatewayFilterSpecTests.java

@@ -39,12 +39,33 @@ public class GatewayFilterSpecTests {
 
 		Route route = routeBuilder.build();
 		assertThat(route.getFilters()).hasSize(1);
-		GatewayFilter filter = route.getFilters().get(0);
+		assertFilter(route.getFilters().get(0), type, order);
+	}
+
+	private void assertFilter(GatewayFilter filter, Class<? extends GatewayFilter> type, int order) {
 		assertThat(filter).isInstanceOf(type);
 		Ordered ordered = (Ordered) filter;
 		assertThat(ordered.getOrder()).isEqualTo(order);
 	}
 
+	@Test
+	public void testFilters() {
+		ConfigurableApplicationContext context = mock(ConfigurableApplicationContext.class);
+		Route.AsyncBuilder routeBuilder = Route.async()
+				.id("123")
+				.uri("abc:123")
+				.predicate(exchange -> true);
+		RouteLocatorBuilder.Builder routes = new RouteLocatorBuilder(context).routes();
+		GatewayFilterSpec spec = new GatewayFilterSpec(routeBuilder, routes);
+		spec.filters(new MyUnorderedFilter(), new MyOrderedFilter());
+
+		Route route = routeBuilder.build();
+		assertThat(route.getFilters()).hasSize(2);
+
+		assertFilter(route.getFilters().get(0), OrderedGatewayFilter.class, 0);
+		assertFilter(route.getFilters().get(1), MyOrderedFilter.class, 1000);
+	}
+
 	protected static class MyOrderedFilter implements GatewayFilter, Ordered {
 		@Override
 		public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {