diff --git a/build.gradle b/build.gradle
index 9a0e6b3..f26ebb0 100644
--- a/build.gradle
+++ b/build.gradle
@@ -54,7 +54,7 @@ uploadArchives {
                 authentication(userName: NEXUS_USERNAME, password: NEXUS_PASSWORD)
             }
             pom.project {
-                version '1.1.20'
+                version '1.1.21'
                 artifactId ARTIFACT_Id
                 groupId GROUP_ID
                 packaging TYPE
diff --git a/src/main/java/com/taover/util/UtilString.java b/src/main/java/com/taover/util/UtilString.java
index 8db5934..7e571a2 100644
--- a/src/main/java/com/taover/util/UtilString.java
+++ b/src/main/java/com/taover/util/UtilString.java
@@ -16,6 +16,9 @@ public class UtilString {
 		if(source == null){
 			return null;
 		}
+		if(source.equals("")){
+			return "";
+		}
 		
 		Pattern pattern = Pattern.compile("\\S");
 		int startIndex = -1;
@@ -37,6 +40,9 @@ public class UtilString {
 		if(source == null){
 			return null;
 		}
+		if(source.equals("")){
+			return "";
+		}
 		
 		Pattern pattern = Pattern.compile("\\S");
 		int endIndex = source.length();
--
libgit2 0.21.2