From c3e5e4cafad82c85c67c6cb433cdade6639851c2 Mon Sep 17 00:00:00 2001
From: pyh_uestc <664254320@qq.com>
Date: Fri, 24 May 2019 15:19:07 +0800
Subject: [PATCH] fix thread-unsafe in NacosRefreshHistory

---
 .../cloud/alibaba/nacos/refresh/NacosRefreshHistory.java | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/spring-cloud-alibaba-nacos-config/src/main/java/org/springframework/cloud/alibaba/nacos/refresh/NacosRefreshHistory.java b/spring-cloud-alibaba-nacos-config/src/main/java/org/springframework/cloud/alibaba/nacos/refresh/NacosRefreshHistory.java
index ec5a83ca..eeac91a1 100644
--- a/spring-cloud-alibaba-nacos-config/src/main/java/org/springframework/cloud/alibaba/nacos/refresh/NacosRefreshHistory.java
+++ b/spring-cloud-alibaba-nacos-config/src/main/java/org/springframework/cloud/alibaba/nacos/refresh/NacosRefreshHistory.java
@@ -27,10 +27,15 @@ public class NacosRefreshHistory {
 
 	private LinkedList<Record> records = new LinkedList<>();
 
-	private DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
+	private ThreadLocal<DateFormat> dateFormat = new ThreadLocal<DateFormat>(){
+		@Override
+		protected DateFormat initialValue() {
+			return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
+		}
+	};
 
 	public void add(String dataId, String md5) {
-		records.addFirst(new Record(dateFormat.format(new Date()), dataId, md5));
+		records.addFirst(new Record(dateFormat.get().format(new Date()), dataId, md5));
 		if (records.size() > MAX_SIZE) {
 			records.removeLast();
 		}