diff --git a/blade-core-tool/src/main/java/org/springblade/core/tool/utils/XmlUtil.java b/blade-core-tool/src/main/java/org/springblade/core/tool/utils/XmlUtil.java
index eec6c03..286e482 100644
--- a/blade-core-tool/src/main/java/org/springblade/core/tool/utils/XmlUtil.java
+++ b/blade-core-tool/src/main/java/org/springblade/core/tool/utils/XmlUtil.java
@@ -264,8 +264,8 @@ public class XmlUtil {
 	 * 内部类单例
 	 */
 	private static class XmlHelperHolder {
-		private static DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
-		private static XPathFactory xPathFactory = XPathFactory.newInstance();
+		private static final DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
+		private static final XPathFactory xPathFactory = XPathFactory.newInstance();
 	}
 
 }