Added caching of DatatypeFactory instances to ConstructionStrategies (#…

…777) (#778)
DozerMapper · Dec 17, 2019 · 2114be1 · 2114be1
1 parent 506403b
commit 2114be1
Showing 1 changed file with 12 additions and 7 deletions.
diff --git a/core/src/main/java/com/github/dozermapper/core/factory/ConstructionStrategies.java b/core/src/main/java/com/github/dozermapper/core/factory/ConstructionStrategies.java
@@ -409,19 +409,24 @@ private static <T> T newInstance(Class<T> clazz) {
 
     private static class XmlGregorian implements BeanCreationStrategy {
 
+        // Instantiating a DatatypeFactory with DatatypeFactory.newInstance() is expensive, so this should be cached.
+        // Regrettably the spec does not require implementations to be thread safe, so we are defensively using
+        // thread local caching here.
+        private static final ThreadLocal<DatatypeFactory> datatypeFactoryHolder = ThreadLocal.withInitial(() -> {
+            try {
+                return DatatypeFactory.newInstance();
+            } catch (DatatypeConfigurationException e) {
+                throw new MappingException(e);
+            }
+        });
+
         public boolean isApplicable(BeanCreationDirective directive) {
             Class<?> actualClass = directive.getActualClass();
             return XMLGregorianCalendar.class.isAssignableFrom(actualClass);
         }
 
         public Object create(BeanCreationDirective directive) {
-            DatatypeFactory dataTypeFactory;
-            try {
-                dataTypeFactory = DatatypeFactory.newInstance();
-            } catch (DatatypeConfigurationException e) {
-                throw new MappingException(e);
-            }
-            return dataTypeFactory.newXMLGregorianCalendar();
+            return datatypeFactoryHolder.get().newXMLGregorianCalendar();
         }
 
     }