#567 - Add extra attributes to Link and use for HAL mediatype.

Adds many additional attributes defined in RFC5988 and verifies they work properly in the neutral representation of Link while also being rendered properly in the HAL module.

Related tickets: #100, #417, #235
Previous pull requests: #240, #238, #223, #79

Author: gregturn

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -15,6 +15,13 @@
  */
 package org.springframework.hateoas;
 
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.experimental.Wither;
+
 import java.io.Serializable;
 import java.util.Collections;
 import java.util.HashMap;
@@ -37,9 +44,14 @@
  * Value object for links.
  * 
  * @author Oliver Gierke
+ * @author Greg Turnquist
  */
 @XmlType(name = "link", namespace = Link.ATOM_NAMESPACE)
 @JsonIgnoreProperties("templated")
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@AllArgsConstructor(access = AccessLevel.PACKAGE)
+@Getter
+@EqualsAndHashCode(of = {"rel", "href", "hreflang", "media", "title", "deprecation"})
 public class Link implements Serializable {
 
 	private static final long serialVersionUID = -9037755944661782121L;
@@ -53,8 +65,13 @@ public class Link implements Serializable {
 	public static final String REL_NEXT = "next";
 	public static final String REL_LAST = "last";
 
-	@XmlAttribute private String rel;
-	@XmlAttribute private String href;
+	@XmlAttribute @Wither private String rel;
+	@XmlAttribute @Wither private String href;
+	@XmlAttribute @Wither private String hreflang;
+	@XmlAttribute @Wither private String media;
+	@XmlAttribute @Wither private String title;
+	@XmlAttribute @Wither private String type;
+	@XmlAttribute @Wither private String deprecation;
 	@XmlTransient @JsonIgnore private UriTemplate template;
 
 	/**
@@ -93,41 +110,6 @@ public Link(UriTemplate template, String rel) {
 		this.rel = rel;
 	}
 
-	/**
-	 * Empty constructor required by the marshalling framework.
-	 */
-	protected Link() {
-
-	}
-
-	/**
-	 * Returns the actual URI the link is pointing to.
-	 * 
-	 * @return
-	 */
-	public String getHref() {
-		return href;
-	}
-
-	/**
-	 * Returns the rel of the link.
-	 * 
-	 * @return
-	 */
-	public String getRel() {
-		return rel;
-	}
-
-	/**
-	 * Returns a {@link Link} pointing to the same URI but with the given relation.
-	 * 
-	 * @param rel must not be {@literal null} or empty.
-	 * @return
-	 */
-	public Link withRel(String rel) {
-		return new Link(href, rel);
-	}
-
 	/**
 	 * Returns a {@link Link} pointing to the same URI but with the {@code self} relation.
 	 * 
@@ -195,46 +177,35 @@ private UriTemplate getUriTemplate() {
 		return template;
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
-	 * @see java.lang.Object#equals(java.lang.Object)
+	 * @see java.lang.Object#toString()
 	 */
 	@Override
-	public boolean equals(Object obj) {
+	public String toString() {
+		String linkString = String.format("<%s>;rel=\"%s\"", href, rel);
 
-		if (this == obj) {
-			return true;
+		if (hreflang != null) {
+			linkString += ";hreflang=\"" + hreflang + "\"";
 		}
 
-		if (!(obj instanceof Link)) {
-			return false;
+		if (media != null) {
+			linkString += ";media=\"" + media + "\"";
 		}
 
-		Link that = (Link) obj;
-
-		return this.href.equals(that.href) && this.rel.equals(that.rel);
-	}
-
-	/* 
-	 * (non-Javadoc)
-	 * @see java.lang.Object#hashCode()
-	 */
-	@Override
-	public int hashCode() {
+		if (title != null) {
+			linkString += ";title=\"" + title + "\"";
+		}
 
-		int result = 17;
-		result += 31 * href.hashCode();
-		result += 31 * rel.hashCode();
-		return result;
-	}
+		if (type != null) {
+			linkString += ";type=\"" + type + "\"";
+		}
 
-	/* 
-	 * (non-Javadoc)
-	 * @see java.lang.Object#toString()
-	 */
-	@Override
-	public String toString() {
-		return String.format("<%s>;rel=\"%s\"", href, rel);
+		if (deprecation != null) {
+			linkString += ";deprecation=\"" + deprecation + "\"";
+		}
+		
+		return linkString;
 	}
 
 	/**
@@ -263,7 +234,29 @@ public static Link valueOf(String element) {
 				throw new IllegalArgumentException("Link does not provide a rel attribute!");
 			}
 
-			return new Link(matcher.group(1), attributes.get("rel"));
+			Link link = new Link(matcher.group(1), attributes.get("rel"));
+
+			if (attributes.containsKey("hreflang")) {
+				link = link.withHreflang(attributes.get("hreflang"));
+			}
+
+			if (attributes.containsKey("media")) {
+				link = link.withMedia(attributes.get("media"));
+			}
+
+			if (attributes.containsKey("title")) {
+				link = link.withTitle(attributes.get("title"));
+			}
+
+			if (attributes.containsKey("type")) {
+				link = link.withType(attributes.get("type"));
+			}
+
+			if (attributes.containsKey("deprecation")) {
+				link = link.withDeprecation(attributes.get("deprecation"));
+			}
+
+			return link;
 
 		} else {
 			throw new IllegalArgumentException(String.format("Given link header %s is not RFC5988 compliant!", element));
@@ -283,7 +276,7 @@ private static Map<String, String> getAttributeMap(String source) {
 		}
 
 		Map<String, String> attributes = new HashMap<String, String>();
-		Pattern keyAndValue = Pattern.compile("(\\w+)=\"(\\p{Lower}[\\p{Lower}\\p{Digit}\\.\\-]*|" + URI_PATTERN + ")\"");
+		Pattern keyAndValue = Pattern.compile("(\\w+)=\"(\\p{Lower}[\\p{Lower}\\p{Digit}\\.\\-\\s]*|" + URI_PATTERN + ")\"");
 		Matcher matcher = keyAndValue.matcher(source);
 
 		while (matcher.find()) {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2016 the original author or authors.
+ * Copyright 2013-2017 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.
@@ -29,10 +29,11 @@
  * Value object to represent a list of {@link Link}s.
  * 
  * @author Oliver Gierke
+ * @author Greg Turnquist
  */
 public class Links implements Iterable<Link> {
 
-	private static final Pattern LINK_HEADER_PATTERN = Pattern.compile("(<[^>]*>;rel=\"[^\"]*\")");
+	private static final Pattern LINK_HEADER_PATTERN = Pattern.compile("(<[^>]*>(;\\w+=\"[^\"]*\")+)");
 
 	static final Links NO_LINKS = new Links(Collections.<Link> emptyList());
 

src/main/java/org/springframework/hateoas/hal/LinkMixin.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -28,13 +28,46 @@
  * 
  * @author Alexander Baetz
  * @author Oliver Gierke
+ * @author Greg Turnquist
  */
-@JsonIgnoreProperties(value = "rel")
+@JsonIgnoreProperties({"rel", "media"})
 abstract class LinkMixin extends Link {
 
 	private static final long serialVersionUID = 4720588561299667409L;
 
-	/* 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.Link#getHreflang()
+	 */
+	@Override
+	@JsonInclude(Include.NON_NULL)
+	public abstract String getHreflang();
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.Link#getTitle()
+	 */
+	@Override
+	@JsonInclude(Include.NON_NULL)
+	public abstract String getTitle();
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.Link#getType()
+	 */
+	@Override
+	@JsonInclude(Include.NON_NULL)
+	public abstract String getType();
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.Link#getDeprecation()
+	 */
+	@Override
+	@JsonInclude(Include.NON_NULL)
+	public abstract String getDeprecation();
+	
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.hateoas.Link#isTemplate()
 	 */

src/test/java/org/springframework/hateoas/AbstractJackson2MarshallingIntegrationTest.java

@@ -1,17 +1,34 @@
+/*
+ * Copyright 2012-2017 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package org.springframework.hateoas;
 
 import java.io.StringWriter;
 import java.io.Writer;
 
 import org.junit.Before;
 
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.databind.ObjectMapper;
 
 /**
  * Base class to test objects against the Jackson 2.0 {@link ObjectMapper}.
  * 
  * @author Oliver Gierke
  * @author Jon Brisbin
+ * @author Greg Turnquist
  */
 public abstract class AbstractJackson2MarshallingIntegrationTest {
 
@@ -20,6 +37,7 @@ public abstract class AbstractJackson2MarshallingIntegrationTest {
 	@Before
 	public void setUp() {
 		mapper = new ObjectMapper();
+		mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
 	}
 
 	protected String write(Object object) throws Exception {

src/test/java/org/springframework/hateoas/LinkUnitTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -28,6 +28,7 @@
  * Unit tests for {@link Link}.
  * 
  * @author Oliver Gierke
+ * @author Greg Turnquist
  */
 public class LinkUnitTest {
 
@@ -103,21 +104,46 @@ public void returnsNullForNullOrEmptyLink() {
 		assertThat(Link.valueOf(""), is(nullValue()));
 	}
 
+	/**
+	 * @see #54
+	 * @see #100
+	 */
 	@Test
 	public void parsesRFC5988HeaderIntoLink() {
 
 		assertThat(Link.valueOf("</something>;rel=\"foo\""), is(new Link("/something", "foo")));
 		assertThat(Link.valueOf("</something>;rel=\"foo\";title=\"Some title\""), is(new Link("/something", "foo")));
+		assertThat(Link.valueOf("</customer/1>;rel=\"self\";hreflang=\"en\";media=\"pdf\";title=\"pdf customer copy\";type=\"portable document\";deprecation=\"http://example.com/customers/deprecated\""),
+			is(new Link("/customer/1")
+				.withHreflang("en")
+				.withMedia("pdf")
+				.withTitle("pdf customer copy")
+				.withType("portable document")
+				.withDeprecation("http://example.com/customers/deprecated")));
+	}
+
+	/**
+	 * @see #100
+	 */
+	@Test
+	public void ignoresUnrecognizedAttributes() {
+		Link link = Link.valueOf("</something>;rel=\"foo\";unknown=\"should fail\"");
+
+		assertThat(link.getHref(), is("/something"));
+		assertThat(link.getRel(), is("foo"));
 	}
 
 	@Test(expected = IllegalArgumentException.class)
 	public void rejectsMissingRelAttribute() {
-		Link.valueOf("</something>);title=\"title\"");
+		Link.valueOf("</something>;title=\"title\"");
 	}
 
 	@Test(expected = IllegalArgumentException.class)
 	public void rejectsLinkWithoutAttributesAtAll() {
-		Link.valueOf("</something>);title=\"title\"");
+
+		Link link = Link.valueOf("</something>");
+
+		System.out.println(link);
 	}
 
 	@Test(expected = IllegalArgumentException.class)