From e98c2dbb36daaf76c56c73f4630367a9006bc7e8 Mon Sep 17 00:00:00 2001
From: Alfredo Diaz <alfredo.diaz@therore.net>
Date: Sun, 17 May 2015 01:29:28 +0200
Subject: [PATCH] prevent NullPointerException if znode contains no data. TODO
 comment about possible race conditions due to method TreeCache.process(..) is
 asynchronous

---
 .../cloud/zookeeper/config/ZookeeperPropertySource.java    | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperPropertySource.java b/spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperPropertySource.java
index bf024c88..9ab7a72b 100644
--- a/spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperPropertySource.java
+++ b/spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperPropertySource.java
@@ -42,6 +42,11 @@ public class ZookeeperPropertySource extends EnumerablePropertySource<CuratorFra
 			cache = TreeCache.newBuilder(source, context).build();
 			cache.start();
 			running = true;
+            /*
+                TODO: race condition since TreeCache.process(..) is invoked asynchronously.
+                Methods getProperty and getPropertyNames could be invoked before that TreeCache.process(..) receives
+                all the WatchedEvents.
+            */
 		}
 		catch (NoNodeException e) {
 			// no node, ignore
@@ -74,7 +79,7 @@ public class ZookeeperPropertySource extends EnumerablePropertySource<CuratorFra
 			return;
 		for (Map.Entry<String, ChildData> entry : children.entrySet()) {
 			ChildData child = entry.getValue();
-			if (child.getData().length == 0) {
+			if (child.getData()==null || child.getData().length == 0) {
 				findKeys(keys, child.getPath());
 			}
 			else {