Fix #1883

Author: cowtowncoder

release-notes/VERSION

@@ -18,6 +18,8 @@ Versions: 3.x (for earlier see VERSION-2.x)
  (reported by timo-schmid@github)
 #1789: Add `createGenerator` methods in `ObjectMapper`, `ObjectWriter`
 #1790: Add `createParser` methods in `ObjectMapper`, `ObjectReader`
+#1883: Add "abstract type mapping" for deserialization from `Map<ENUMTYPE,V>`
+  into `EnumMap` (and `Set<ENUMTYPE>` to `EnumSet<EnumType>`) 
 #1888: Merge `ResolvableSerializer` into `JsonSerializer`, `ResolvableDeserializer`
  into `JsonDeserializer`
 #1889: Merge `ContextualSerializer` into `JsonSerializer`, `ContextualDeserializer`

src/main/java/com/fasterxml/jackson/databind/ObjectMapper.java

@@ -1361,13 +1361,11 @@ public ObjectMapper enableDefaultTyping(DefaultTyping dti) {
      */
     public ObjectMapper enableDefaultTyping(DefaultTyping applicability, JsonTypeInfo.As includeAs)
     {
-        /* 18-Sep-2014, tatu: Let's add explicit check to ensure no one tries to
-         *   use "As.EXTERNAL_PROPERTY", since that will not work (with 2.5+)
-         */
+        // 18-Sep-2014, tatu: Let's add explicit check to ensure no one tries to
+        //   use "As.EXTERNAL_PROPERTY", since that will not work (with 2.5+)
         if (includeAs == JsonTypeInfo.As.EXTERNAL_PROPERTY) {
             throw new IllegalArgumentException("Cannot use includeAs of "+includeAs);
         }
-        
         TypeResolverBuilder<?> typer = new DefaultTypeResolverBuilder(applicability);
         // we'll always use full class name, when using defaulting
         typer = typer.init(JsonTypeInfo.Id.CLASS, null);
@@ -1667,7 +1665,7 @@ public DateFormat getDateFormat() {
      *
      * @param hi Instantiator to use; if null, use the default implementation
      */
-    public Object setHandlerInstantiator(HandlerInstantiator hi)
+    public ObjectMapper setHandlerInstantiator(HandlerInstantiator hi)
     {
         _deserializationConfig = _deserializationConfig.with(hi);
         _serializationConfig = _serializationConfig.with(hi);

src/main/java/com/fasterxml/jackson/databind/deser/BasicDeserializerFactory.java

@@ -1206,8 +1206,14 @@ public JsonDeserializer<?> createCollectionDeserializer(DeserializationContext c
         if (deser == null) {
             Class<?> collectionClass = type.getRawClass();
             if (contentDeser == null) { // not defined by annotation
+                // [databind#1853]: Map `Set<ENUM>` to `EnumSet<ENUM>`
+                if (contentType.isEnumType() && (collectionClass == Set.class)) {
+                    collectionClass = EnumSet.class;
+                    type = (CollectionType) config.getTypeFactory().constructSpecializedType(type, collectionClass);
+                }
                 // One special type: EnumSet:
                 if (EnumSet.class.isAssignableFrom(collectionClass)) {
+                    // 25-Jan-2018, tatu: shouldn't we pass `contentDeser`?
                     deser = new EnumSetDeserializer(contentType, null);
                 }
             }
@@ -1343,6 +1349,12 @@ public JsonDeserializer<?> createMapDeserializer(DeserializationContext ctxt,
         if (deser == null) {
             // Value handling is identical for all, but EnumMap requires special handling for keys
             Class<?> mapClass = type.getRawClass();
+            // [databind#1853]: Map `Map<ENUM,x>` to `EnumMap<ENUM,x>`
+            if ((mapClass == Map.class) && keyType.isEnumType()) {
+                mapClass = EnumMap.class;
+                type = (MapType) config.getTypeFactory().constructSpecializedType(type, mapClass);
+//                type = (MapType) config.getTypeFactory().constructMapType(mapClass, keyType, contentType);
+            }
             if (EnumMap.class.isAssignableFrom(mapClass)) {
                 ValueInstantiator inst;
 

src/main/java/com/fasterxml/jackson/databind/deser/std/EnumSetDeserializer.java

@@ -30,8 +30,6 @@ public class EnumSetDeserializer
      * Specific override for this instance (from proper, or global per-type overrides)
      * to indicate whether single value may be taken to mean an unwrapped one-element array
      * or not. If null, left to global defaults.
-     *
-     * @since 2.7
      */
     protected final Boolean _unwrapSingle;
 
@@ -55,9 +53,6 @@ public EnumSetDeserializer(JavaType enumType, JsonDeserializer<?> deser)
         _unwrapSingle = null;
     }
 
-    /**
-     * @since 2.7
-     */
     @SuppressWarnings("unchecked" )
     protected EnumSetDeserializer(EnumSetDeserializer base,
             JsonDeserializer<?> deser, Boolean unwrapSingle) {

src/test/java/com/fasterxml/jackson/databind/deser/jdk/EnumDeserializationTest.java

@@ -345,20 +345,21 @@ public void testAllowUnknownEnumValuesReadAsNullWithCreatorMethod() throws Excep
 
     public void testAllowUnknownEnumValuesForEnumSets() throws Exception
     {
-        ObjectReader reader = MAPPER.reader(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_AS_NULL);
-        EnumSet<TestEnum> result = reader.forType(new TypeReference<EnumSet<TestEnum>>() { })
+        EnumSet<TestEnum> result = MAPPER.reader(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_AS_NULL)
+                .forType(new TypeReference<EnumSet<TestEnum>>() { })
                 .readValue("[\"NO-SUCH-VALUE\"]");
         assertEquals(0, result.size());
     }
-    
+
     public void testAllowUnknownEnumValuesAsMapKeysReadAsNull() throws Exception
     {
-        ObjectReader reader = MAPPER.reader(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_AS_NULL);
-        ClassWithEnumMapKey result = reader.forType(ClassWithEnumMapKey.class)
+        ClassWithEnumMapKey result = MAPPER.reader(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_AS_NULL)
+                .forType(ClassWithEnumMapKey.class)
                 .readValue("{\"map\":{\"NO-SUCH-VALUE\":\"val\"}}");
-        assertTrue(result.map.containsKey(null));
+        // 25-Jan-2018, tatu: as per [databind#1883], we upgrade it to `EnumMap`, which won't accept nulls...
+        assertEquals(0, result.map.size());
     }
-    
+
     public void testDoNotAllowUnknownEnumValuesAsMapKeysWhenReadAsNullDisabled() throws Exception
     {
         assertFalse(MAPPER.isEnabled(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_AS_NULL));

src/test/java/com/fasterxml/jackson/databind/deser/jdk/EnumMapDeserializationTest.java

@@ -169,9 +169,8 @@ public void testUnknownKeyAsNull() throws Exception
                 .readerFor(new TypeReference<Map<TestEnumWithDefault,String>>() { })
                 .with(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_AS_NULL)
                 .readValue("{\"unknown\":\"value\"}");
-        // 04-Jan-2017, tatu: Not sure if this is weird or not, but since `null`s are typically
-        //    ok for "regular" JDK Maps...
-        assertEquals(1, value2.size());
-        assertEquals("value", value2.get(null));
+        // 25-Jan-2018, tatu: as per [databind#1883], we upgrade it to `EnumMap`, which won't accept nulls...
+        assertEquals(0, value2.size());
+        assertEquals(EnumMap.class, value2.getClass());
     }
 }

src/test/java/com/fasterxml/jackson/databind/ser/TestEnumSerialization.java

@@ -214,7 +214,6 @@ public void testEnumUsingToString() throws Exception
         assertEquals("\"c2\"", sw.toString());
     }
 
-    // Test [JACKSON-214]
     public void testSubclassedEnums() throws Exception
     {
         assertEquals("\"B\"", MAPPER.writeValueAsString(EnumWithSubClass.B));