Backport findPolymorphicTypeInfo

Author: JooHyukKim

src/main/java/com/fasterxml/jackson/databind/introspect/JacksonAnnotationIntrospector.java

@@ -1508,24 +1508,29 @@ protected PropertyName _findConstructorName(Annotated a)
     protected TypeResolverBuilder<?> _findTypeResolver(MapperConfig<?> config,
             Annotated ann, JavaType baseType)
     {
+        // since 2.16 : backporting {@link JsonTypeInfo.Value} from 3.0
+        final AnnotationIntrospector ai = config.getAnnotationIntrospector();
+        JsonTypeInfo.Value typeInfo = ai.findPolymorphicTypeInfo(config, ann);
+
+        JsonTypeInfo info = _findAnnotation(ann, JsonTypeInfo.class);
+
         // First: maybe we have explicit type resolver?
         TypeResolverBuilder<?> b;
-        JsonTypeInfo info = _findAnnotation(ann, JsonTypeInfo.class);
         JsonTypeResolver resAnn = _findAnnotation(ann, JsonTypeResolver.class);
 
         if (resAnn != null) {
-            if (info == null) {
+            if (typeInfo == null) {
                 return null;
             }
             // let's not try to force access override (would need to pass
             // settings through if we did, since that's not doable on some platforms)
             b = config.typeResolverBuilderInstance(ann, resAnn.value());
         } else { // if not, use standard one, if indicated by annotations
-            if (info == null) {
+            if (typeInfo == null) {
                 return null;
             }
             // bit special; must return 'marker' to block use of default typing:
-            if (info.use() == JsonTypeInfo.Id.NONE) {
+            if (typeInfo.getIdType() == JsonTypeInfo.Id.NONE) {
                 return _constructNoTypeResolverBuilder();
             }
             b = _constructStdTypeResolverBuilder();
@@ -1537,26 +1542,26 @@ protected TypeResolverBuilder<?> _findTypeResolver(MapperConfig<?> config,
         if (idRes != null) {
             idRes.init(baseType);
         }
-        b = b.init(info.use(), idRes);
+        b = b.init(typeInfo.getIdType(), idRes);
         // 13-Aug-2011, tatu: One complication; external id only works for properties;
         //    so if declared for a Class, we will need to map it to "PROPERTY"
         //    instead of "EXTERNAL_PROPERTY"
-        JsonTypeInfo.As inclusion = info.include();
+        JsonTypeInfo.As inclusion = typeInfo.getInclusionType();
         if (inclusion == JsonTypeInfo.As.EXTERNAL_PROPERTY && (ann instanceof AnnotatedClass)) {
             inclusion = JsonTypeInfo.As.PROPERTY;
         }
         b = b.inclusion(inclusion);
-        b = b.typeProperty(info.property());
-        Class<?> defaultImpl = info.defaultImpl();
+        b = b.typeProperty(typeInfo.getPropertyName());
+        Class<?> defaultImpl = typeInfo.getDefaultImpl();
 
         // 08-Dec-2014, tatu: To deprecate `JsonTypeInfo.None` we need to use other placeholder(s);
         //   and since `java.util.Void` has other purpose (to indicate "deser as null"), we'll instead
         //   use `JsonTypeInfo.class` itself. But any annotation type will actually do, as they have no
         //   valid use (cannot instantiate as default)
-        if (defaultImpl != JsonTypeInfo.None.class && !defaultImpl.isAnnotation()) {
+        if (defaultImpl != null && defaultImpl != JsonTypeInfo.None.class && !defaultImpl.isAnnotation()) {
             b = b.defaultImpl(defaultImpl);
         }
-        b = b.typeIdVisibility(info.visible());
+        b = b.typeIdVisibility(typeInfo.getIdVisible());
         return b;
     }
 

src/main/java/com/fasterxml/jackson/databind/jsontype/impl/StdTypeResolverBuilder.java

@@ -1,5 +1,6 @@
 package com.fasterxml.jackson.databind.jsontype.impl;
 
+import com.fasterxml.jackson.databind.introspect.Annotated;
 import java.util.Collection;
 
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
@@ -436,11 +437,11 @@ protected boolean _strictTypeIdHandling(DeserializationConfig config, JavaType b
      *
      * @return true if the class has type resolver annotations, false otherwise
      *
-     * @since 2.15
+     * @since 2.15, using {@code ai.findPolymorphicTypeInfo(config, ac)} since 2.16.
      */
     protected boolean _hasTypeResolver(DeserializationConfig config, JavaType baseType) {
         AnnotatedClass ac = AnnotatedClassResolver.resolveWithoutSuperTypes(config,  baseType.getRawClass());
         AnnotationIntrospector ai = config.getAnnotationIntrospector();
-        return ai.findTypeResolver(config, ac, baseType) != null;
+        return ai.findPolymorphicTypeInfo(config, ac) != null;
     }
 }