Fix #1328

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -9,6 +9,7 @@ Project: jackson-databind
 #955: Add `MapperFeature.USE_BASE_TYPE_AS_DEFAULT_IMPL` to use declared base type
    as `defaultImpl` for polymorphic deserialization
   (contributed by mikeldpl@github)
+#1328: External property polymorphic deserialization does not work with enums
 #1565: Deserialization failure with Polymorphism using JsonTypeInfo `defaultImpl`,
   subtype as target
 #1964: Failed to specialize `Map` type during serialization where key type

src/main/java/com/fasterxml/jackson/databind/deser/impl/ExternalTypeHandler.java

@@ -262,7 +262,6 @@ public Object complete(JsonParser p, DeserializationContext ctxt,
         for (int i = 0; i < len; ++i) {
             String typeId = _typeIds[i];
             final ExtTypedProperty extProp = _properties[i];
-
             if (typeId == null) {
                 // let's allow missing both type and property (may already have been set, too)
                 if (_tokens[i] == null) {
@@ -294,11 +293,21 @@ public Object complete(JsonParser p, DeserializationContext ctxt,
                 SettableBeanProperty typeProp = extProp.getTypeProperty();
                 // for now, should only be needed for creator properties, too
                 if ((typeProp != null) && (typeProp.getCreatorIndex() >= 0)) {
-                    buffer.assignParameter(typeProp, typeId);
+                    // 31-May-2018, tatu: [databind#1328] if id is NOT plain `String`, need to
+                    //    apply deserializer... fun fun.
+                    final Object v;
+                    if (typeProp.getType().hasRawClass(String.class)) {
+                        v = typeId;
+                    } else {
+                        TokenBuffer tb = new TokenBuffer(p, ctxt);
+                        tb.writeString(typeId);
+                        v = typeProp.getValueDeserializer().deserialize(tb.asParserOnFirstToken(), ctxt);
+                        tb.close();
+                    }
+                    buffer.assignParameter(typeProp, v);
                 }
             }
         }
-
         Object bean = creator.build(ctxt, buffer);
         // third: assign non-creator properties
         for (int i = 0; i < len; ++i) {

src/main/java/com/fasterxml/jackson/databind/deser/impl/PropertyValueBuffer.java

@@ -177,7 +177,6 @@ public Object[] getParameters(SettableBeanProperty[] props)
                 }
             }
         }
-
         return _creatorParameters;
     }
 
@@ -263,7 +262,6 @@ public boolean assignParameter(SettableBeanProperty prop, Object value)
     {
         final int ix = prop.getCreatorIndex();
         _creatorParameters[ix] = value;
-
         if (_paramsSeenBig == null) {
             int old = _paramsSeen;
             int newValue = (old | (1 << ix));

src/test/java/com/fasterxml/jackson/databind/jsontype/ext/ExternalTypeIdWithEnum1328Test.java

@@ -0,0 +1,91 @@
+package com.fasterxml.jackson.databind.jsontype.ext;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.annotation.JsonTypeIdResolver;
+import com.fasterxml.jackson.databind.jsontype.TypeIdResolver;
+
+public class ExternalTypeIdWithEnum1328Test extends BaseMapTest
+{
+    public interface Animal { }
+
+    public static class Dog implements Animal {
+        public String dogStuff;
+    }
+    
+    public enum AnimalType {
+        Dog;
+    }
+
+    public static class AnimalAndType {
+        public AnimalType type;
+
+        @JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, 
+            include = JsonTypeInfo.As.EXTERNAL_PROPERTY, 
+            property = "type")
+        @JsonTypeIdResolver(AnimalResolver.class)   
+        private Animal animal;
+
+        public AnimalAndType() { }
+
+        // problem is this annotation
+        @java.beans.ConstructorProperties({"type", "animal"})
+        public AnimalAndType(final AnimalType type, final Animal animal) {
+            this.type = type;
+            this.animal = animal;
+        }
+    }
+
+    static class AnimalResolver implements TypeIdResolver {
+        @Override
+        public void init(JavaType bt) { }
+
+        @Override
+        public String idFromValue(Object value) {
+            return null;
+        }
+
+        @Override
+        public String idFromValueAndType(Object value, Class<?> suggestedType) {
+            return null;
+        }
+
+        @Override
+        public String idFromBaseType() {
+            throw new UnsupportedOperationException("Missing action type information - Can not construct");
+        }
+
+        @Override
+        public JavaType typeFromId(DatabindContext context, String id) throws IOException {
+            if (AnimalType.Dog.toString().equals(id)) {
+                return context.constructType(Dog.class);
+            }
+            throw new IllegalArgumentException("What is a " + id);
+        }
+
+        @Override
+        public String getDescForKnownTypeIds() {
+            return null;
+        }
+
+        @Override
+        public JsonTypeInfo.Id getMechanism() {
+            return JsonTypeInfo.Id.CUSTOM;
+        } 
+    }
+
+    public void testExample() throws Exception {
+        ObjectMapper mapper = new ObjectMapper();
+        
+        String json = mapper.writerWithDefaultPrettyPrinter()
+                .writeValueAsString(Arrays.asList(new AnimalAndType(AnimalType.Dog, new Dog())));
+        List<AnimalAndType> list = mapper.readerFor(new TypeReference<List<AnimalAndType>>() { })
+            .readValue(json);
+        assertNotNull(list);
+    }
+}