From a9128bb48ebd619a80df086cf386864f9f62058c Mon Sep 17 00:00:00 2001
From: Jiaju Zhuang <zhuangjiaju@qq.com>
Date: Wed, 28 Aug 2019 09:36:34 +0800
Subject: [PATCH] fix #506

---
 .../excel/write/metadata/holder/AbstractWriteHolder.java    | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/alibaba/excel/write/metadata/holder/AbstractWriteHolder.java b/src/main/java/com/alibaba/excel/write/metadata/holder/AbstractWriteHolder.java
index e7728377..c210f281 100644
--- a/src/main/java/com/alibaba/excel/write/metadata/holder/AbstractWriteHolder.java
+++ b/src/main/java/com/alibaba/excel/write/metadata/holder/AbstractWriteHolder.java
@@ -23,6 +23,7 @@ import com.alibaba.excel.metadata.Head;
 import com.alibaba.excel.metadata.TableStyle;
 import com.alibaba.excel.metadata.property.ExcelContentProperty;
 import com.alibaba.excel.metadata.property.RowHeightProperty;
+import com.alibaba.excel.util.CollectionUtils;
 import com.alibaba.excel.write.handler.CellWriteHandler;
 import com.alibaba.excel.write.handler.DefaultWriteHandlerLoader;
 import com.alibaba.excel.write.handler.RowWriteHandler;
@@ -267,7 +268,10 @@ public abstract class AbstractWriteHolder extends AbstractHolder implements Writ
 
         // add
         if (parentHandlerMap != null) {
-            handlerList.addAll(parentHandlerMap.get(WriteHandler.class));
+            List<WriteHandler> parentWriteHandler = parentHandlerMap.get(WriteHandler.class);
+            if (!CollectionUtils.isEmpty(parentWriteHandler)) {
+                handlerList.addAll(parentWriteHandler);
+            }
         }
 
         // sort