Incorporate feedback from @rstoyanchev.

Improve ResourceAssemblerSupport by introducing a dedicated method instead of an overload. Got rid of EntityId in the course. ControllerLinkBuilder now inspects type hierarchy for @RequestMapping annotations instead of the class only. Made links list in ResourceSupport final. Polished variable names and JavaDoc.

src/main/java/org/springframework/hateoas/ResourceSupport.java

@@ -31,7 +31,7 @@ import org.springframework.util.Assert;
 public class ResourceSupport implements Identifiable<Link> {
 
 	@XmlElement(name = "link", namespace = Link.ATOM_NAMESPACE)
-	private List<Link> links;
+	private final List<Link> links;
 
 	public ResourceSupport() {
 		this.links = new ArrayList<Link>();

src/main/java/org/springframework/hateoas/mvc/ControllerLinkBuilder.java

@@ -35,16 +35,16 @@ import org.springframework.web.util.UriTemplate;
  */
 public class ControllerLinkBuilder {
 
-	private final UriComponents builder;
+	private final UriComponents uriComponents;
 
 	/**
 	 * Creates a new {@link ControllerLinkBuilder}.
 	 * 
-	 * @param builder must not be {@literal null}.
+	 * @param uriComponents must not be {@literal null}.
 	 */
 	private ControllerLinkBuilder(UriComponentsBuilder builder) {
 		Assert.notNull(builder);
-		this.builder = builder.build();
+		this.uriComponents = builder.build();
 	}
 
 	/**
@@ -59,7 +59,7 @@ public class ControllerLinkBuilder {
 
 	public static ControllerLinkBuilder linkTo(Class<?> controller, Object... parameters) {
 
-		RequestMapping annotation = controller.getAnnotation(RequestMapping.class);
+		RequestMapping annotation = AnnotationUtils.findAnnotation(controller, RequestMapping.class);
 		String[] mapping = annotation == null ? new String[0] : (String[]) AnnotationUtils.getValue(annotation);
 
 		if (mapping.length > 1) {
@@ -89,12 +89,12 @@ public class ControllerLinkBuilder {
 		}
 
 		String[] segments = StringUtils.tokenizeToStringArray(object.toString(), "/");
-		return new ControllerLinkBuilder(UriComponentsBuilder.fromUri(builder.toUri()).pathSegment(segments));
+		return new ControllerLinkBuilder(UriComponentsBuilder.fromUri(uriComponents.toUri()).pathSegment(segments));
 	}
 
 	/**
-	 * Adds the given {@link AbstractEntity}'s id as sub-resource. Will simply return the current builder if the given
-	 * entity is {@literal null}.
+	 * Adds the given {@link AbstractEntity}'s id as sub-resource. Will simply return the current uriComponents if the
+	 * given entity is {@literal null}.
 	 * 
 	 * @param identifyable
 	 * @return
@@ -109,12 +109,12 @@ public class ControllerLinkBuilder {
 	}
 
 	/**
-	 * Returns a URI resulting from the builder.
+	 * Returns a URI resulting from the uriComponents.
 	 * 
 	 * @return
 	 */
 	public URI toUri() {
-		return builder.encode().toUri();
+		return uriComponents.encode().toUri();
 	}
 
 	public Link withRel(String rel) {

src/main/java/org/springframework/hateoas/mvc/ResourceAssemblerSupport.java

@@ -36,25 +36,6 @@ import org.springframework.util.Assert;
 public abstract class ResourceAssemblerSupport<T extends Identifiable<?>, D extends ResourceSupport> implements
 		ResourceAssembler<T, D> {
 
-	public static class EntityId {
-
-		private final Object id;
-
-		public EntityId(Object id) {
-			Assert.notNull(id);
-			this.id = id;
-		}
-
-		public static EntityId id(Object object) {
-			return new EntityId(object);
-		}
-
-		@Override
-		public String toString() {
-			return this.id.toString();
-		}
-	}
-
 	private final Class<?> controllerClass;
 	private final Class<D> resourceType;
 
@@ -77,11 +58,12 @@ public abstract class ResourceAssemblerSupport<T extends Identifiable<?>, D exte
 	 * Converts all given entities into resources.
 	 * 
 	 * @see #toResource(Object)
-	 * @param entities
+	 * @param entities must not be {@literal null}.
 	 * @return
 	 */
 	public List<D> toResources(Iterable<? extends T> entities) {
 
+		Assert.notNull(entities);
 		List<D> result = new ArrayList<D>();
 
 		for (T entity : entities) {
@@ -102,21 +84,21 @@ public abstract class ResourceAssemblerSupport<T extends Identifiable<?>, D exte
 	}
 
 	protected D createResource(T entity, Object... parameters) {
-		return createResource(entity, EntityId.id(entity.getId()), parameters);
+		return createResourceWithId(entity.getId(), entity, parameters);
 	}
 
 	/**
 	 * Creates a new resource with a self link to the given id.
 	 * 
-	 * @param entity
-	 * @param id
+	 * @param entity must not be {@literal null}.
+	 * @param id must not be {@literal null}.
 	 * @return
 	 */
-	protected D createResource(T entity, EntityId id) {
-		return createResource(entity, id, new Object[0]);
+	protected D createResourceWithId(Object id, T entity) {
+		return createResourceWithId(id, entity, new Object[0]);
 	}
 
-	protected D createResource(T entity, EntityId id, Object... parameters) {
+	protected D createResourceWithId(Object id, T entity, Object... parameters) {
 
 		Assert.notNull(entity);
 		Assert.notNull(id);
@@ -154,4 +136,4 @@ public abstract class ResourceAssemblerSupport<T extends Identifiable<?>, D exte
 	protected D instantiateResource(T entity) {
 		return BeanUtils.instantiateClass(resourceType);
 	}
-}
+}