Merge pull request #2300 from harawata/gh/2297-quick-return

Avoid unnecessary `ConcurrentHashMap#put()` calls in `TypeHandlerRegistry`

Author: harawata

src/main/java/org/apache/ibatis/type/TypeHandlerRegistry.java

@@ -54,7 +54,7 @@
  */
 public final class TypeHandlerRegistry {
 
-  private final Map<JdbcType, TypeHandler<?>>  jdbcTypeHandlerMap = new EnumMap<>(JdbcType.class);
+  private final Map<JdbcType, TypeHandler<?>> jdbcTypeHandlerMap = new EnumMap<>(JdbcType.class);
   private final Map<Type, Map<JdbcType, TypeHandler<?>>> typeHandlerMap = new ConcurrentHashMap<>();
   private final TypeHandler<Object> unknownTypeHandler;
   private final Map<Class<?>, TypeHandler<?>> allTypeHandlersMap = new HashMap<>();
@@ -252,10 +252,10 @@ private <T> TypeHandler<T> getTypeHandler(Type type, JdbcType jdbcType) {
 
   private Map<JdbcType, TypeHandler<?>> getJdbcHandlerMap(Type type) {
     Map<JdbcType, TypeHandler<?>> jdbcHandlerMap = typeHandlerMap.get(type);
-    if (NULL_TYPE_HANDLER_MAP.equals(jdbcHandlerMap)) {
-      return null;
+    if (jdbcHandlerMap != null) {
+      return NULL_TYPE_HANDLER_MAP.equals(jdbcHandlerMap) ? null : jdbcHandlerMap;
     }
-    if (jdbcHandlerMap == null && type instanceof Class) {
+    if (type instanceof Class) {
       Class<?> clazz = (Class<?>) type;
       if (Enum.class.isAssignableFrom(clazz)) {
         Class<?> enumClass = clazz.isAnonymousClass() ? clazz.getSuperclass() : clazz;
@@ -292,7 +292,7 @@ private Map<JdbcType, TypeHandler<?>> getJdbcHandlerMapForEnumInterfaces(Class<?
   }
 
   private Map<JdbcType, TypeHandler<?>> getJdbcHandlerMapForSuperclass(Class<?> clazz) {
-    Class<?> superclass =  clazz.getSuperclass();
+    Class<?> superclass = clazz.getSuperclass();
     if (superclass == null || Object.class.equals(superclass)) {
       return null;
     }