#841 - Added builder API to HalLinkRelation.

This allows more convenient setup of multiple HalLinkRelation instances for the same curie.

Additional unit tests.

src/main/java/org/springframework/hateoas/mediatype/hal/HalLinkRelation.java

@@ -105,6 +105,16 @@ public class HalLinkRelation implements LinkRelation, MessageSourceResolvable {
 		return new HalLinkRelation(null, rel);
 	}
 
+	/**
+	 * Creates a new {@link HalLinkRelationBuilder} for the given curie.
+	 *
+	 * @param curie must not be {@literal null} or empty.
+	 * @return will never be {@literal null}.
+	 */
+	public static HalLinkRelationBuilder curieBuilder(String curie) {
+		return relation -> new HalLinkRelation(curie, relation);
+	}
+
 	/**
 	 * Creates a new {@link HalLinkRelation} curied to the given value.
 	 *
@@ -162,6 +172,22 @@ public class HalLinkRelation implements LinkRelation, MessageSourceResolvable {
 				.toArray(String[]::new);
 	}
 
+	/**
+	 * Simple builder interface to easily create multiple {@link HalLinkRelation}s for a single curie.
+	 *
+	 * @author Oliver Drotbohm
+	 */
+	public interface HalLinkRelationBuilder {
+
+		/**
+		 * Creates a new {@link HalLinkRelation} based on the current curie settings.
+		 *
+		 * @param relation must not be {@literal null} or empty.
+		 * @return will never be {@literal null}.
+		 */
+		HalLinkRelation relation(String relation);
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see java.lang.Object#toString()