Add support for optionally matching trailing / in path predicate. Fixes #511

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/handler/predicate/PathRoutePredicateFactory.java

@@ -17,6 +17,7 @@
 
 package org.springframework.cloud.gateway.handler.predicate;
 
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.function.Predicate;
@@ -40,6 +41,7 @@ import static org.springframework.http.server.PathContainer.parsePath;
  */
 public class PathRoutePredicateFactory extends AbstractRoutePredicateFactory<PathRoutePredicateFactory.Config> {
 	private static final Log log = LogFactory.getLog(RoutePredicateFactory.class);
+	private static final String MATCH_OPTIONAL_TRAILING_SEPARATOR_KEY = "matchOptionalTrailingSeparator";
 
 	private PathPatternParser pathPatternParser = new PathPatternParser();
 
@@ -53,12 +55,13 @@ public class PathRoutePredicateFactory extends AbstractRoutePredicateFactory<Pat
 
 	@Override
 	public List<String> shortcutFieldOrder() {
-		return Collections.singletonList(PATTERN_KEY);
+		return Arrays.asList(PATTERN_KEY, MATCH_OPTIONAL_TRAILING_SEPARATOR_KEY);
 	}
 
 	@Override
 	public Predicate<ServerWebExchange> apply(Config config) {
 		synchronized (this.pathPatternParser) {
+			pathPatternParser.setMatchOptionalTrailingSeparator(config.isMatchOptionalTrailingSeparator());
 			config.pathPattern = this.pathPatternParser.parse(config.pattern);
 		}
 		return exchange -> {
@@ -88,6 +91,7 @@ public class PathRoutePredicateFactory extends AbstractRoutePredicateFactory<Pat
 	public static class Config {
 		private String pattern;
 		private PathPattern pathPattern;
+		private boolean matchOptionalTrailingSeparator = true;
 
 		public String getPattern() {
 			return pattern;
@@ -98,10 +102,20 @@ public class PathRoutePredicateFactory extends AbstractRoutePredicateFactory<Pat
 			return this;
 		}
 
+		public boolean isMatchOptionalTrailingSeparator() {
+			return matchOptionalTrailingSeparator;
+		}
+
+		public Config setMatchOptionalTrailingSeparator(boolean matchOptionalTrailingSeparator) {
+			this.matchOptionalTrailingSeparator = matchOptionalTrailingSeparator;
+			return this;
+		}
+
 		@Override
 		public String toString() {
 			return new ToStringCreator(this)
 					.append("pattern", pattern)
+					.append("matchOptionalTrailingSeparator", matchOptionalTrailingSeparator)
 					.toString();
 		}
 	}

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

@@ -170,6 +170,19 @@ public class PredicateSpec extends UriSpec {
 				.applyAsync(c -> c.setPattern(pattern)));
 	}
 
+	/**
+	 * A predicate that checks if the path of the request matches the given pattern
+	 * @param pattern the pattern to check the path against.
+	 *                The pattern is a {@link org.springframework.util.PathMatcher} pattern
+	 * @param matchOptionalTrailingSeparator set to false if you do not want this path to match
+	 *                                       when there is a trailing <code>/</code>
+	 * @return a {@link BooleanSpec} to be used to add logical operators
+	 */
+	public BooleanSpec path(String pattern, boolean matchOptionalTrailingSeparator) {
+		return asyncPredicate(getBean(PathRoutePredicateFactory.class)
+				.applyAsync(c -> c.setPattern(pattern).setMatchOptionalTrailingSeparator(matchOptionalTrailingSeparator)));
+	}
+
 	/**
 	 * This predicate is BETA and may be subject to change in a future release.
 	 * A predicate that checks the contents of the request body

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/handler/predicate/PathRoutePredicateFactoryTests.java

@@ -44,6 +44,12 @@ public class PathRoutePredicateFactoryTests extends BaseWebClientTests {
 				.expectStatus().isOk()
 				.expectHeader().valueEquals(HANDLER_MAPPER_HEADER, RoutePredicateHandlerMapping.class.getSimpleName())
 				.expectHeader().valueEquals(ROUTE_ID_HEADER, "path_test");
+
+		//since the configuration does not allow the trailing / to match this should fail
+		testClient.get().uri("/abc/123/function/")
+				.header(HttpHeaders.HOST, "www.path.org")
+				.exchange()
+				.expectStatus().is4xxClientError();
 	}
 
 	@Test

spring-cloud-gateway-core/src/test/resources/application.yml

@@ -128,7 +128,7 @@ spring:
       - id: path_test
         uri: ${test.uri}
         predicates:
-        - Path=/{org}/{scope}/function
+        - Path=/{org}/{scope}/function,false
         - Host=**.path.org
         filters:
         - SetPath=/anything/{org}{scope}