From 9b0326b7f1f05bf3ff092be45b3039092151d7e5 Mon Sep 17 00:00:00 2001
From: Victor Uria Valle <victor.uria.valle@cern.ch>
Date: Sun, 14 Jul 2024 03:21:36 +0200
Subject: [PATCH] Fix thread safety in Json.mapper() (refs #4672)

---
 .../src/main/java/io/swagger/v3/core/util/Json.java      | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/modules/swagger-core/src/main/java/io/swagger/v3/core/util/Json.java b/modules/swagger-core/src/main/java/io/swagger/v3/core/util/Json.java
index 84c318fd62..899c7476ed 100644
--- a/modules/swagger-core/src/main/java/io/swagger/v3/core/util/Json.java
+++ b/modules/swagger-core/src/main/java/io/swagger/v3/core/util/Json.java
@@ -6,13 +6,12 @@
 
 public class Json {
 
-    private static ObjectMapper mapper;
+    private static final class ObjectMapperHolder {
+        private static final ObjectMapper MAPPER = ObjectMapperFactory.createJson();
+    }
 
     public static ObjectMapper mapper() {
-        if (mapper == null) {
-            mapper = ObjectMapperFactory.createJson();
-        }
-        return mapper;
+        return ObjectMapperHolder.MAPPER;
     }
 
     public static ObjectWriter pretty() {