Fix #82

Author: cowtowncoder

release-notes/VERSION

@@ -8,6 +8,7 @@ Project: jackson-datatype-guava
 
 #80: Relax OSGi version constraints for Guava dependency.
  (requested by Benson M)
+#82: Problem with polymorphic value types for `Optional`, with 2.6
 
 2.6.1 (09-Aug-2015)
 

src/main/java/com/fasterxml/jackson/datatype/guava/ser/GuavaOptionalSerializer.java

@@ -90,7 +90,7 @@ public JsonSerializer<?> createContextual(SerializerProvider provider,
                     (provider.isEnabled(MapperFeature.USE_STATIC_TYPING)
                     || _referredType.isFinal())) {
                 return withResolved(property,
-                        provider.findPrimaryPropertySerializer(_referredType, property),
+                        _findSerializer(provider, _referredType, _property),
                         _unwrapper);
             }
         } else {
@@ -130,6 +130,7 @@ public boolean isEmpty(SerializerProvider prov, Optional<?> value) {
         return (value == null) || !value.isPresent();
     }
 
+    @Override
     public boolean isUnwrappingSerializer() {
         return (_unwrapper != null);
     }
@@ -212,12 +213,26 @@ protected final JsonSerializer<Object> _findSerializer(SerializerProvider provid
     {
         JsonSerializer<Object> ser = _dynamicSerializers.serializerFor(type);
         if (ser == null) {
-            ser = provider.findPrimaryPropertySerializer(type, _property);
+            ser = _findSerializer(provider, type, _property);
             if (_unwrapper != null) {
                 ser = ser.unwrappingSerializer(_unwrapper);
             }
             _dynamicSerializers = _dynamicSerializers.newWith(type, ser);
         }
         return ser;
     }
+
+    private final JsonSerializer<Object> _findSerializer(SerializerProvider provider,
+            Class<?> type, BeanProperty prop) throws JsonMappingException
+    {
+        // Important: ask for TYPED serializer, in case polymorphic handling is needed!
+        return provider.findTypedValueSerializer(type, true, prop);
+    }
+
+    private final JsonSerializer<Object> _findSerializer(SerializerProvider provider,
+        JavaType type, BeanProperty prop) throws JsonMappingException
+    {
+        // Important: ask for TYPED serializer, in case polymorphic handling is needed!
+        return provider.findTypedValueSerializer(type, true, prop);
+    }
 }

src/test/java/com/fasterxml/jackson/datatype/guava/OptionalBasicTest.java

@@ -4,9 +4,10 @@
 
 import com.fasterxml.jackson.annotation.*;
 import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
+import com.fasterxml.jackson.annotation.JsonTypeInfo.As;
 import com.fasterxml.jackson.core.type.TypeReference;
-import com.fasterxml.jackson.databind.JavaType;
-import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.*;
+
 import com.google.common.base.Optional;
 
 public class OptionalBasicTest extends ModuleTestBase
@@ -37,6 +38,20 @@ public void link(Unit u) {
         }
     }
 
+    // To test handling of polymorphic value types
+    
+    public static class Container {
+        public Optional<Contained> contained;
+    }
+
+    @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = As.PROPERTY)
+    @JsonSubTypes({
+        @JsonSubTypes.Type(name = "ContainedImpl", value = ContainedImpl.class),
+    })
+    public static interface Contained { }
+
+    public static class ContainedImpl implements Contained { }
+    
     /*
     /**********************************************************************
     /* Test methods
@@ -228,9 +243,23 @@ public void testOptionalCollection() throws Exception {
         }
     }
 
-    // [Issue#48]
+    // [datatype-guava#48]
     public void testDeserNull() throws Exception {
         Optional<?> value = MAPPER.readValue("\"\"", new TypeReference<Optional<Integer>>() {});
         assertFalse(value.isPresent());
     }
+
+    // [datatype-guava#81]
+    public void testPolymorphic() throws Exception
+    {
+        final Container dto = new Container();
+        dto.contained = Optional.of((Contained) new ContainedImpl());
+        
+        final String json = MAPPER.writeValueAsString(dto);
+
+        final Container fromJson = MAPPER.readValue(json, Container.class);
+        assertNotNull(fromJson.contained);
+        assertTrue(fromJson.contained.isPresent());
+        assertSame(ContainedImpl.class, fromJson.contained.get().getClass());
+    }
 }