From c141896af740dcc2fef1e242f64dff8ed41b6981 Mon Sep 17 00:00:00 2001
From: Oliver Drotbohm <odrotbohm@vmware.com>
Date: Tue, 16 Feb 2021 12:52:24 +0100
Subject: [PATCH] #1470 - Mapping discoverer now keeps trailing slashes around.

---
 .../server/core/AnnotationMappingDiscoverer.java | 10 ++++++----
 .../AnnotationMappingDiscovererUnitTest.java     | 16 ++++++++++++++++
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/main/java/org/springframework/hateoas/server/core/AnnotationMappingDiscoverer.java b/src/main/java/org/springframework/hateoas/server/core/AnnotationMappingDiscoverer.java
index 481bc3ed..206b3deb 100644
--- a/src/main/java/org/springframework/hateoas/server/core/AnnotationMappingDiscoverer.java
+++ b/src/main/java/org/springframework/hateoas/server/core/AnnotationMappingDiscoverer.java
@@ -24,11 +24,11 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
-import java.util.regex.Pattern;
 
 import org.springframework.http.HttpMethod;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 import org.springframework.web.bind.annotation.RequestMethod;
 
 /**
@@ -40,8 +40,6 @@ import org.springframework.web.bind.annotation.RequestMethod;
  */
 public class AnnotationMappingDiscoverer implements MappingDiscoverer {
 
-	private static final Pattern MULTIPLE_SLASHES = Pattern.compile("/{2,}");
-
 	private final Class<? extends Annotation> annotationType;
 	private final String mappingAttributeName;
 
@@ -193,6 +191,10 @@ public class AnnotationMappingDiscoverer implements MappingDiscoverer {
 
 			String part = parts[i];
 
+			if (!StringUtils.hasText(part)) {
+				continue;
+			}
+
 			if (i != 0) {
 				result.append("/");
 			}
@@ -200,7 +202,7 @@ public class AnnotationMappingDiscoverer implements MappingDiscoverer {
 			result.append(part.contains(":") ? cleanupPart(part) : part);
 		}
 
-		return MULTIPLE_SLASHES.matcher(result.toString()).replaceAll("/");
+		return (mapping.endsWith("/") ? result.append("/") : result).toString();
 	}
 
 	private static String cleanupPart(String part) {
diff --git a/src/test/java/org/springframework/hateoas/server/core/AnnotationMappingDiscovererUnitTest.java b/src/test/java/org/springframework/hateoas/server/core/AnnotationMappingDiscovererUnitTest.java
index 9702ab58..9982bab9 100755
--- a/src/test/java/org/springframework/hateoas/server/core/AnnotationMappingDiscovererUnitTest.java
+++ b/src/test/java/org/springframework/hateoas/server/core/AnnotationMappingDiscovererUnitTest.java
@@ -168,6 +168,14 @@ class AnnotationMappingDiscovererUnitTest {
 		assertThat(discoverer.getMapping(method)).isEqualTo("/type/spring-web/{symbolicName}-{version}{extension}");
 	}
 
+	@Test // #1470
+	void keepsTrailingSlash() throws Exception {
+
+		Method method = TrailingSlashes.class.getMethod("trailingSlash");
+
+		assertThat(discoverer.getMapping(method)).isEqualTo("/api/myentities/");
+	}
+
 	@RequestMapping("/type")
 	interface MyController {
 
@@ -253,4 +261,12 @@ class AnnotationMappingDiscovererUnitTest {
 		@RequestMapping({ "/method", "/methodAlias" })
 		void method();
 	}
+
+	// #1470
+
+	interface TrailingSlashes {
+
+		@RequestMapping("/api/myentities/")
+		Object trailingSlash();
+	}
 }