From b738cb148cb2a15e72a5c27200eca2d4b383bf9c Mon Sep 17 00:00:00 2001
From: Steve Loughran <stevel@apache.org>
Date: Wed, 17 Oct 2018 10:29:09 +0100
Subject: [PATCH] HADOOP-15854. AuthToken Use StringBuilder instead of
 StringBuffer. Contributed by Beluga Behr.

---
 .../apache/hadoop/security/authentication/util/AuthToken.java   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hadoop-common-project/hadoop-auth/src/main/java/org/apache/hadoop/security/authentication/util/AuthToken.java b/hadoop-common-project/hadoop-auth/src/main/java/org/apache/hadoop/security/authentication/util/AuthToken.java
index e959f65b0b..844501c678 100644
--- a/hadoop-common-project/hadoop-auth/src/main/java/org/apache/hadoop/security/authentication/util/AuthToken.java
+++ b/hadoop-common-project/hadoop-auth/src/main/java/org/apache/hadoop/security/authentication/util/AuthToken.java
@@ -128,7 +128,7 @@ public boolean isExpired() {
    * Generates the token.
    */
   private void generateToken() {
-    StringBuffer sb = new StringBuffer();
+    StringBuilder sb = new StringBuilder();
     sb.append(USER_NAME).append("=").append(getUserName()).append(ATTR_SEPARATOR);
     sb.append(PRINCIPAL).append("=").append(getName()).append(ATTR_SEPARATOR);
     sb.append(TYPE).append("=").append(getType()).append(ATTR_SEPARATOR);