Index: org/apache/tomcat/util/buf/Base64.java
===================================================================
--- org/apache/tomcat/util/buf/Base64.java	(revision 831814)
+++ org/apache/tomcat/util/buf/Base64.java	(working copy)
@@ -239,7 +239,7 @@
 
     public static String base64Decode( String orig ) {
 	char chars[]=orig.toCharArray();
-	StringBuffer sb=new StringBuffer();
+	StringBuilder sb=new StringBuilder();
 	int i=0;
 
 	int shift = 0;   // # of excess bits stored in accum
Index: org/apache/tomcat/util/buf/HexUtils.java
===================================================================
--- org/apache/tomcat/util/buf/HexUtils.java	(revision 831814)
+++ org/apache/tomcat/util/buf/HexUtils.java	(working copy)
@@ -129,7 +129,7 @@
      */
     public static String convert(byte bytes[]) {
 
-	StringBuffer sb = new StringBuffer(bytes.length * 2);
+	StringBuilder sb = new StringBuilder(bytes.length * 2);
 	for (int i = 0; i < bytes.length; i++) {
 	    sb.append(convertDigit((int) (bytes[i] >> 4)));
 	    sb.append(convertDigit((int) (bytes[i] & 0x0f)));
Index: org/apache/tomcat/util/buf/UDecoder.java
===================================================================
--- org/apache/tomcat/util/buf/UDecoder.java	(revision 831814)
+++ org/apache/tomcat/util/buf/UDecoder.java	(working copy)
@@ -204,7 +204,7 @@
 	if( (!query || str.indexOf( '+' ) < 0) && str.indexOf( '%' ) < 0 )
 	    return str;
 	
-        StringBuffer dec = new StringBuffer();    // decoded string output
+        StringBuilder dec = new StringBuilder();    // decoded string output
         int strPos = 0;
         int strLen = str.length();