From 14a5a794908008470f03b0578136f21a8df4cb7e Mon Sep 17 00:00:00 2001
From: Greg Turnquist <gturnquist@pivotal.io>
Date: Wed, 7 Jun 2017 09:30:26 -0500
Subject: [PATCH] #594 - Protect against Spring 5 non-null inputs.

Spring 5 has adopted a "no nulls" policy that causes certain methods to throw exceptions instead of returning a null. This updates Spring HATEOAS to handle it suitably.

Original pull request: #595.
---
 .../hateoas/core/AnnotationMappingDiscoverer.java           | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/main/java/org/springframework/hateoas/core/AnnotationMappingDiscoverer.java b/src/main/java/org/springframework/hateoas/core/AnnotationMappingDiscoverer.java
index a40cb44e..18141fca 100644
--- a/src/main/java/org/springframework/hateoas/core/AnnotationMappingDiscoverer.java
+++ b/src/main/java/org/springframework/hateoas/core/AnnotationMappingDiscoverer.java
@@ -108,7 +108,11 @@ public class AnnotationMappingDiscoverer implements MappingDiscoverer {
 
 	private String[] getMappingFrom(Annotation annotation) {
 
-		Object value = mappingAttributeName == null ? getValue(annotation) : getValue(annotation, mappingAttributeName);
+		Object value = null;
+
+		if (annotation != null) {
+			value = mappingAttributeName == null ? getValue(annotation) : getValue(annotation, mappingAttributeName);
+		}
 
 		if (value instanceof String) {
 			return new String[] { (String) value };