diff --git a/src/main/java/com/alibaba/druid/util/StringUtils.java b/src/main/java/com/alibaba/druid/util/StringUtils.java
index 6b5ef08567..7b8e7dabd2 100644
--- a/src/main/java/com/alibaba/druid/util/StringUtils.java
+++ b/src/main/java/com/alibaba/druid/util/StringUtils.java
@@ -15,12 +15,8 @@
  */
 package com.alibaba.druid.util;
 
-import java.util.ArrayList;
-import java.util.Collection;
 import java.util.LinkedHashMap;
-import java.util.List;
 import java.util.Map;
-import java.util.StringTokenizer;
 
 import com.alibaba.druid.support.logging.Log;
 import com.alibaba.druid.support.logging.LogFactory;