#269 - Polishing.

Simplified slash removal and made sure slashes occuring multiple times are removed properly.

Original pull request: #423.

src/main/java/org/springframework/hateoas/core/AnnotationMappingDiscoverer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ import static org.springframework.core.annotation.AnnotationUtils.*;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
+import java.util.regex.Pattern;
 
 import org.springframework.util.Assert;
 
@@ -29,6 +30,8 @@ import org.springframework.util.Assert;
  */
 public class AnnotationMappingDiscoverer implements MappingDiscoverer {
 
+	private static final Pattern MULTIPLE_SLASHES = Pattern.compile("\\/{2,}");
+
 	private final Class<? extends Annotation> annotationType;
 	private final String mappingAttributeName;
 
@@ -68,8 +71,8 @@ public class AnnotationMappingDiscoverer implements MappingDiscoverer {
 		String[] mapping = getMappingFrom(findAnnotation(type, annotationType));
 
 		if (mapping.length > 1) {
-			throw new IllegalStateException(String.format("Multiple class level mappings defined on class %s!",
-					type.getName()));
+			throw new IllegalStateException(
+					String.format("Multiple class level mappings defined on class %s!", type.getName()));
 		}
 
 		return mapping.length == 0 ? null : mapping[0];
@@ -99,8 +102,8 @@ public class AnnotationMappingDiscoverer implements MappingDiscoverer {
 		String[] mapping = getMappingFrom(findAnnotation(method, annotationType));
 
 		if (mapping.length > 1) {
-			throw new IllegalStateException(String.format("Multiple method level mappings defined on method %s!",
-					method.toString()));
+			throw new IllegalStateException(
+					String.format("Multiple method level mappings defined on method %s!", method.toString()));
 		}
 
 		String typeMapping = getMapping(type);
@@ -112,16 +115,6 @@ public class AnnotationMappingDiscoverer implements MappingDiscoverer {
 		return typeMapping == null || "/".equals(typeMapping) ? mapping[0] : join(typeMapping, mapping[0]);
 	}
 
-	private String join(String typeMapping, String mapping) {
-		StringBuilder builder = new StringBuilder();
-
-		builder.append(typeMapping.endsWith("/") ? typeMapping.substring(0, typeMapping.length() - 1) : typeMapping);
-		builder.append('/');
-		builder.append(mapping.startsWith("/") ? mapping.substring(1) : mapping);
-
-		return builder.toString();
-	}
-
 	private String[] getMappingFrom(Annotation annotation) {
 
 		Object value = mappingAttributeName == null ? getValue(annotation) : getValue(annotation, mappingAttributeName);
@@ -137,4 +130,15 @@ public class AnnotationMappingDiscoverer implements MappingDiscoverer {
 		throw new IllegalStateException(String.format(
 				"Unsupported type for the mapping attribute! Support String and String[] but got %s!", value.getClass()));
 	}
+
+	/**
+	 * Joins the given mappings making sure exactly one slash.
+	 * 
+	 * @param typeMapping must not be {@literal null} or empty.
+	 * @param mapping must not be {@literal null} or empty.
+	 * @return
+	 */
+	private static String join(String typeMapping, String mapping) {
+		return MULTIPLE_SLASHES.matcher(typeMapping.concat("/").concat(mapping)).replaceAll("/");
+	}
 }