From 81f635f47f0737eb551bef1aa55afdf7b268253d Mon Sep 17 00:00:00 2001
From: Yiqun Lin <yqlin@apache.org>
Date: Thu, 4 Oct 2018 10:30:30 +0800
Subject: [PATCH] HADOOP-15817. Reuse Object Mapper in KMSJSONReader.
 Contributed by Jonathan Eagles.

---
 .../apache/hadoop/crypto/key/kms/server/KMSJSONReader.java    | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hadoop-common-project/hadoop-kms/src/main/java/org/apache/hadoop/crypto/key/kms/server/KMSJSONReader.java b/hadoop-common-project/hadoop-kms/src/main/java/org/apache/hadoop/crypto/key/kms/server/KMSJSONReader.java
index f6f670be0a..af781f5277 100644
--- a/hadoop-common-project/hadoop-kms/src/main/java/org/apache/hadoop/crypto/key/kms/server/KMSJSONReader.java
+++ b/hadoop-common-project/hadoop-kms/src/main/java/org/apache/hadoop/crypto/key/kms/server/KMSJSONReader.java
@@ -38,6 +38,7 @@
 @Consumes(MediaType.APPLICATION_JSON)
 @InterfaceAudience.Private
 public class KMSJSONReader implements MessageBodyReader<Object> {
+  private static final ObjectMapper MAPPER = new ObjectMapper();
 
   @Override
   public boolean isReadable(Class<?> type, Type genericType,
@@ -51,7 +52,6 @@ public Object readFrom(Class<Object> type, Type genericType,
       Annotation[] annotations, MediaType mediaType,
       MultivaluedMap<String, String> httpHeaders, InputStream entityStream)
       throws IOException, WebApplicationException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.readValue(entityStream, type);
+    return MAPPER.readValue(entityStream, type);
   }
 }