Generalized logic to find an annotated Enum value and extracted it to ClassUtil.

Author: Alejandro Rivera

src/main/java/com/fasterxml/jackson/databind/util/ClassUtil.java

@@ -842,6 +842,34 @@ public static Class<? extends Enum<?>> findEnumType(Class<?> cls)
         return (Class<? extends Enum<?>>) cls;
     }
 
+    /**
+     * A method that will look for the first Enum value annotated with the given Annotation.
+     * <p>
+     * If there's more than one value annotated, the first one found will be returned. Which one exactly is used is undetermined.
+     *
+     * @param enumClass The Enum class to scan for a value with the given annotation
+     * @param annotationClass The annotation to look for.
+     * @return the Enum value annotated with the given Annotation or {@code null} if none is found.
+     * @throws IllegalArgumentException if there's a reflection issue accessing the Enum
+     * @since 2.8
+     */
+    public static <T extends Annotation> Enum<?> findFirstAnnotatedEnumValue(Class<Enum<?>> enumClass, Class<T> annotationClass) {
+        Field[] fields = getDeclaredFields(enumClass);
+        for (Field field : fields) {
+            Annotation defaultValueAnnotation = field.getAnnotation(annotationClass);
+            if (defaultValueAnnotation != null && field.isEnumConstant()) {
+                try {
+                    Method valueOf = enumClass.getDeclaredMethod("valueOf", String.class);  // using `getMethod` causes IllegalAccessException
+                    valueOf.setAccessible(true);
+                    return enumClass.cast(valueOf.invoke(null, field.getName()));
+                } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
+                    throw new IllegalArgumentException("Could not extract Enum annotated with " + annotationClass.getSimpleName(), e);
+                }
+            }
+        }
+        return null;
+    }
+
     /*
     /**********************************************************
     /* Jackson-specific stuff

src/main/java/com/fasterxml/jackson/databind/util/EnumResolver.java

@@ -1,11 +1,9 @@
 package com.fasterxml.jackson.databind.util;
 
 import com.fasterxml.jackson.annotation.JsonEnumDefaultValue;
-import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.AnnotationIntrospector;
+import com.fasterxml.jackson.databind.introspect.JacksonAnnotationIntrospector;
 
-import java.lang.reflect.Field;
-import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.*;
 
@@ -53,30 +51,11 @@ public static EnumResolver constructFor(Class<Enum<?>> enumCls, AnnotationIntros
             map.put(name, enumValues[i]);
         }
 
-        Enum<?> defaultEnum = determineDefaultEnumValue(enumCls);
+        Enum<?> defaultEnum = ClassUtil.findFirstAnnotatedEnumValue(enumCls, JsonEnumDefaultValue.class);
 
         return new EnumResolver(enumCls, enumValues, map, defaultEnum);
     }
 
-    private static Enum<?> determineDefaultEnumValue(Class<Enum<?>> enumCls) {
-        Field[] fields = ClassUtil.getDeclaredFields(enumCls);
-        for (Field field : fields) {
-            JsonEnumDefaultValue defaultValueAnnotation = field.getAnnotation(JsonEnumDefaultValue.class);
-            if (defaultValueAnnotation != null && field.isEnumConstant()) {
-                try {
-                    Method valueOf = enumCls.getDeclaredMethod("valueOf", String.class);    // using `getMethod` causes IllegalAccessException
-                    valueOf.setAccessible(true);
-                    return enumCls.cast(valueOf.invoke(null, field.getName()));
-                } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
-                    java.util.logging.Logger.getLogger(EnumResolver.class.getName())
-                        .warning("Could not extract Enum annotated with " + JsonEnumDefaultValue.class.getSimpleName()
-                            + " due to: " + e.getLocalizedMessage());
-                }
-            }
-        }
-        return null;
-    }
-
     /**
      * Factory method for constructing resolver that maps from Enum.toString() into
      * Enum value
@@ -90,8 +69,9 @@ public static EnumResolver constructUsingToString(Class<Enum<?>> enumCls)
             Enum<?> e = enumValues[i];
             map.put(e.toString(), e);
         }
-        Enum<?> defaultValue = determineDefaultEnumValue(enumCls);
-        return new EnumResolver(enumCls, enumValues, map, defaultValue);
+
+        Enum<?> defaultEnum = ClassUtil.findFirstAnnotatedEnumValue(enumCls, JsonEnumDefaultValue.class);
+        return new EnumResolver(enumCls, enumValues, map, defaultEnum);
     }    
 
     public static EnumResolver constructUsingMethod(Class<Enum<?>> enumCls,
@@ -112,9 +92,8 @@ public static EnumResolver constructUsingMethod(Class<Enum<?>> enumCls,
             }
         }
 
-        Enum<?> defaultValue = determineDefaultEnumValue(enumCls);
-
-        return new EnumResolver(enumCls, enumValues, map, defaultValue);
+        Enum<?> defaultEnum = ClassUtil.findFirstAnnotatedEnumValue(enumCls, JsonEnumDefaultValue.class);
+        return new EnumResolver(enumCls, enumValues, map, defaultEnum);
     }    
 
     /**