Index: org/apache/catalina/users/MemoryGroup.java
===================================================================
--- org/apache/catalina/users/MemoryGroup.java	(revision 831814)
+++ org/apache/catalina/users/MemoryGroup.java	(working copy)
@@ -182,7 +182,7 @@
      */
     public String toString() {
 
-        StringBuffer sb = new StringBuffer("<group groupname=\"");
+        StringBuilder sb = new StringBuilder("<group groupname=\"");
         sb.append(groupname);
         sb.append("\"");
         if (description != null) {
Index: org/apache/catalina/users/MemoryRole.java
===================================================================
--- org/apache/catalina/users/MemoryRole.java	(revision 831814)
+++ org/apache/catalina/users/MemoryRole.java	(working copy)
@@ -86,7 +86,7 @@
      */
     public String toString() {
 
-        StringBuffer sb = new StringBuffer("<role rolename=\"");
+        StringBuilder sb = new StringBuilder("<role rolename=\"");
         sb.append(rolename);
         sb.append("\"");
         if (description != null) {
Index: org/apache/catalina/users/MemoryUser.java
===================================================================
--- org/apache/catalina/users/MemoryUser.java	(revision 831814)
+++ org/apache/catalina/users/MemoryUser.java	(working copy)
@@ -248,7 +248,7 @@
      */
     public String toString() {
 
-        StringBuffer sb = new StringBuffer("<user username=\"");
+        StringBuilder sb = new StringBuilder("<user username=\"");
         sb.append(RequestUtil.filter(username));
         sb.append("\" password=\"");
         sb.append(RequestUtil.filter(password));
Index: org/apache/catalina/users/MemoryUserDatabase.java
===================================================================
--- org/apache/catalina/users/MemoryUserDatabase.java	(revision 831814)
+++ org/apache/catalina/users/MemoryUserDatabase.java	(working copy)
@@ -610,7 +610,7 @@
      */
     public String toString() {
 
-        StringBuffer sb = new StringBuffer("MemoryUserDatabase[id=");
+        StringBuilder sb = new StringBuilder("MemoryUserDatabase[id=");
         sb.append(this.id);
         sb.append(",pathname=");
         sb.append(pathname);