From 69c62d33cae0d4099ecf472e37c80aaccc9e5fbb Mon Sep 17 00:00:00 2001
From: Terry W Brady <terrywbrady@gmail.com>
Date: Tue, 8 May 2018 15:55:41 -0700
Subject: [PATCH] add initial exception

---
 .../dspace/app/rest/repository/CommunityRestRepository.java   | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/dspace-spring-rest/src/main/java/org/dspace/app/rest/repository/CommunityRestRepository.java b/dspace-spring-rest/src/main/java/org/dspace/app/rest/repository/CommunityRestRepository.java
index 563bccecda..5eec2249df 100644
--- a/dspace-spring-rest/src/main/java/org/dspace/app/rest/repository/CommunityRestRepository.java
+++ b/dspace-spring-rest/src/main/java/org/dspace/app/rest/repository/CommunityRestRepository.java
@@ -96,6 +96,10 @@ public class CommunityRestRepository extends DSpaceRestRepository<CommunityRest,
     // with pagination and authorization check
     @SearchRestMethod(name = "subCommunities")
     public Page<CommunityRest> findSubCommunities(@Param(value = "parent") UUID parentCommunity, Pageable pageable) {
+        if (parentCommunity == null) {
+            throw new IllegalArgumentException("Missing parameter 'parent'.  "
+                    + "This parameter should contain the UUID of a parent community");
+        }
         Context context = obtainContext();
         List<Community> subCommunities = new ArrayList<Community>();
         try {