Polished Resources abstraction.

Added correct equals(…)/hashCode() methods to PagedResource, PageMetadata. Polished toString() methods of ResourceSupport, Resource, Resources and PagedResources. Added factory method to PagedResources to easily create a plain instance from a set of entities.

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

@@ -15,30 +15,117 @@
  */
 package org.springframework.hateoas;
 
+import java.util.ArrayList;
+import java.util.Collection;
+
 import javax.xml.bind.annotation.XmlAttribute;
+import javax.xml.bind.annotation.XmlRootElement;
 
 import org.codehaus.jackson.annotate.JsonAutoDetect;
 import org.codehaus.jackson.annotate.JsonAutoDetect.Visibility;
 import org.codehaus.jackson.annotate.JsonProperty;
+import org.springframework.util.Assert;
 
 /**
  * DTO to implement binding response representations of pageable collections.
  * 
  * @author Oliver Gierke
  */
+@XmlRootElement(name = "entities")
 @JsonAutoDetect(fieldVisibility = Visibility.ANY)
-public class PagedResources<T extends Resource<?>> extends Resources<T> {
+public class PagedResources<T> extends Resources<T> {
 
 	@JsonProperty("page")
-	private PageMetadata pageMetadata;
+	private PageMetadata metadata;
+
+	/**
+	 * Default constructor to allow instantiation by reflection.
+	 */
+	protected PagedResources() {
+		this(new ArrayList<T>(), null);
+	}
+
+	/**
+	 * Creates a new {@link PagedResources} from the given content and {@link PageMetadata}.
+	 * 
+	 * @param content must not be {@literal null}.
+	 * @param metadata
+	 * @param links
+	 */
+	public PagedResources(Collection<T> content, PageMetadata metadata, Link... links) {
+		super(content, links);
+		this.metadata = metadata;
+	}
 
 	/**
 	 * Returns the pagination metadata.
 	 * 
-	 * @return the pageMetadata
+	 * @return the metadata
 	 */
 	public PageMetadata getMetadata() {
-		return pageMetadata;
+		return metadata;
+	}
+
+	/**
+	 * Factory method to easily create a {@link PagedResources} instance from a set of entities and pagination metadata.
+	 * 
+	 * @param content must not be {@literal null}.
+	 * @param metadata
+	 * @return
+	 */
+	@SuppressWarnings("unchecked")
+	public static <T extends Resource<S>, S> PagedResources<T> fromEntities(Iterable<S> content, PageMetadata metadata) {
+
+		Assert.notNull(content);
+		ArrayList<T> resources = new ArrayList<T>();
+
+		for (S element : content) {
+			resources.add((T) new Resource<S>(element));
+		}
+
+		return new PagedResources<T>(resources, metadata);
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.ResourceSupport#toString()
+	 */
+	@Override
+	public String toString() {
+		return String.format("PagedResource { content: %s, metadata: %s }", getContent(), metadata);
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.Resources#equals(java.lang.Object)
+	 */
+	@Override
+	public boolean equals(Object obj) {
+
+		if (this == obj) {
+			return true;
+		}
+
+		if (obj == null || !getClass().equals(obj.getClass())) {
+			return false;
+		}
+
+		PagedResources<?> that = (PagedResources<?>) obj;
+		boolean metadataEquals = this.metadata == null ? that.metadata == null : this.metadata.equals(that.metadata);
+
+		return metadataEquals ? super.equals(obj) : false;
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.Resources#hashCode()
+	 */
+	@Override
+	public int hashCode() {
+
+		int result = super.hashCode();
+		result += this.metadata == null ? 0 : 31 * this.metadata.hashCode();
+		return result;
 	}
 
 	/**
@@ -65,6 +152,24 @@ public class PagedResources<T extends Resource<?>> extends Resources<T> {
 		@JsonProperty
 		private long number;
 
+		protected PageMetadata() {
+
+		}
+
+		/**
+		 * @param size
+		 * @param number
+		 * @param totalElements
+		 * @param totalPages
+		 */
+		public PageMetadata(long size, long number, long totalElements, long totalPages) {
+
+			this.size = size;
+			this.number = number;
+			this.totalElements = totalElements;
+			this.totalPages = totalPages;
+		}
+
 		/**
 		 * Returns the requested size of the page.
 		 * 
@@ -107,8 +212,44 @@ public class PagedResources<T extends Resource<?>> extends Resources<T> {
 		 */
 		@Override
 		public String toString() {
-			return String.format("Page metadata [number: %d, total pages: %d, total elements: %d, size: %d]", number,
+			return String.format("Metadata { number: %d, total pages: %d, total elements: %d, size: %d }", number,
 					totalPages, totalElements, size);
 		}
+
+		/* 
+		 * (non-Javadoc)
+		 * @see java.lang.Object#equals(java.lang.Object)
+		 */
+		@Override
+		public boolean equals(Object obj) {
+
+			if (this == obj) {
+				return true;
+			}
+
+			if (obj == null || !obj.getClass().equals(getClass())) {
+				return false;
+			}
+
+			PageMetadata that = (PageMetadata) obj;
+
+			return this.number == that.number && this.size == that.size && this.totalElements == that.totalElements
+					&& this.totalPages == that.totalPages;
+		}
+
+		/* 
+		 * (non-Javadoc)
+		 * @see java.lang.Object#hashCode()
+		 */
+		@Override
+		public int hashCode() {
+
+			int result = 17;
+			result += 31 * (int) (this.number ^ (this.number >>> 32));
+			result += 31 * (int) (this.size ^ (this.size >>> 32));
+			result += 31 * (int) (this.totalElements ^ (this.totalElements >>> 32));
+			result += 31 * (int) (this.totalPages ^ (this.totalPages >>> 32));
+			return result;
+		}
 	}
 }