[databind#4849] Allow standard defaultTyping with EnumSet<E>

release-notes/VERSION-2.x

@@ -31,15 +31,17 @@ Project: jackson-databind
  (reported by Eduard G)
 #4773: `SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS` should not apply to Maps
   with uncomparable keys
- (requested by @nathanukey)
+ (requested by @nathanukey
+#4849 Not able to deserialize Enum with default typing after upgrading 2.15.4 -> 2.17.1
+ (reported by Kornel Zemla)
 
 2.18.3 (not yet released)
 
 #4827: Subclassed Throwable deserialization fails since v2.18.0 - no creator
   index for property 'cause'
  (reported by @nilswieber)
  (fix by Joo-Hyuk K)
-#4844: Fix wrapped array hanlding wrt `null` by `StdDeserializer`
+#4844: Fix wrapped array handling wrt `null` by `StdDeserializer`
  (fix by Stanislav S)
 
 2.18.2 (27-Nov-2024)

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

@@ -788,8 +788,7 @@ public JsonDeserializer<?> createCollectionDeserializer(DeserializationContext c
             if (contentDeser == null) { // not defined by annotation
                 // One special type: EnumSet:
                 if (EnumSet.class.isAssignableFrom(collectionClass)) {
-                    deser = new EnumSetDeserializer(contentType, null,
-                            contentTypeDeser);
+                    deser = new EnumSetDeserializer(contentType, null);
                 }
             }
         }

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

@@ -32,17 +32,6 @@ public class EnumSetDeserializer
 
     protected JsonDeserializer<Enum<?>> _enumDeserializer;
 
-    /**
-     * If element instances have polymorphic type information, this
-     * is the type deserializer that can handle it.
-     *<p>
-     * NOTE: only added in 2.17 due to new {@code DefaultType} choices
-     * that allow polymorphic deserialization of {@code Enum} types.
-     *
-     * @since 2.17
-     */
-    protected final TypeDeserializer _valueTypeDeserializer;
-
     /**
      * Handler we need for dealing with nulls.
      *
@@ -74,11 +63,12 @@ public class EnumSetDeserializer
      */
 
     /**
-     * @since 2.17
+     * Main constructor for the deserializer.
+     *<p>
+     * NOTE: was temporarily deprecated in 2.17 - 2.18, restored in 2.19
      */
     @SuppressWarnings("unchecked" )
-    public EnumSetDeserializer(JavaType enumType, JsonDeserializer<?> deser,
-            TypeDeserializer valueTypeDeser)
+    public EnumSetDeserializer(JavaType enumType, JsonDeserializer<?> deser)
     {
         super(EnumSet.class);
         _enumType = enumType;
@@ -87,29 +77,19 @@ public EnumSetDeserializer(JavaType enumType, JsonDeserializer<?> deser,
             throw new IllegalArgumentException("Type "+enumType+" not Java Enum type");
         }
         _enumDeserializer = (JsonDeserializer<Enum<?>>) deser;
-        _valueTypeDeserializer = valueTypeDeser;
         _unwrapSingle = null;
         _nullProvider = null;
         _skipNullValues = false;
     }
 
     /**
-     * @deprecated Since 2.17
+     * @deprecated Since 2.19 (was added in 2.17)
      */
     @Deprecated
-    public EnumSetDeserializer(JavaType enumType, JsonDeserializer<?> deser)
+    public EnumSetDeserializer(JavaType enumType, JsonDeserializer<?> deser,
+            TypeDeserializer valueTypeDeser)
     {
-        this(enumType, deser, null);
-    }
-
-    /**
-     * @since 2.7
-     * @deprecated Since 2.10.1
-     */
-    @Deprecated
-    protected EnumSetDeserializer(EnumSetDeserializer base,
-            JsonDeserializer<?> deser, Boolean unwrapSingle) {
-        this(base, deser, base._nullProvider, unwrapSingle);
+        this(enumType, deser);
     }
 
     /**
@@ -121,7 +101,6 @@ protected EnumSetDeserializer(EnumSetDeserializer base,
         super(base);
         _enumType = base._enumType;
         _enumDeserializer = (JsonDeserializer<Enum<?>>) deser;
-        _valueTypeDeserializer = base._valueTypeDeserializer;
         _nullProvider = nuller;
         _skipNullValues = NullsConstantProvider.isSkipper(nuller);
         _unwrapSingle = unwrapSingle;
@@ -135,29 +114,18 @@ public EnumSetDeserializer withDeserializer(JsonDeserializer<?> deser) {
     }
 
     /**
-     * @since 2.10.1
+     * @since 2.19
      */
     public EnumSetDeserializer withResolved(JsonDeserializer<?> deser,
-            TypeDeserializer valueTypeDeser,
             NullValueProvider nuller, Boolean unwrapSingle) {
         if ((Objects.equals(_unwrapSingle, unwrapSingle))
                 && (_enumDeserializer == deser)
-                && (_valueTypeDeserializer == valueTypeDeser)
                 && (_nullProvider == deser)) {
             return this;
         }
         return new EnumSetDeserializer(this, deser, nuller, unwrapSingle);
     }
 
-    /**
-     * @deprecated Since 2.17
-     */
-    @Deprecated
-    public EnumSetDeserializer withResolved(JsonDeserializer<?> deser,
-            NullValueProvider nuller, Boolean unwrapSingle) {
-        return withResolved(deser, _valueTypeDeserializer, nuller, unwrapSingle);
-    }
-
     /*
     /**********************************************************
     /* Basic metadata
@@ -171,9 +139,7 @@ public EnumSetDeserializer withResolved(JsonDeserializer<?> deser,
     @Override
     public boolean isCachable() {
         // One caveat: content deserializer should prevent caching
-        if ((_enumType.getValueHandler() != null)
-                // Another: polymorphic deserialization
-                || (_valueTypeDeserializer != null)) {
+        if (_enumType.getValueHandler() != null) {
             return false;
         }
         return true;
@@ -220,12 +186,7 @@ public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
         } else { // if directly assigned, probably not yet contextual, so:
             deser = ctxt.handleSecondaryContextualization(deser, property, _enumType);
         }
-        // and finally, type deserializer needs context as well
-        TypeDeserializer valueTypeDeser = _valueTypeDeserializer;
-        if (valueTypeDeser != null) {
-            valueTypeDeser = valueTypeDeser.forProperty(property);
-        }
-        return withResolved(deser, valueTypeDeser,
+        return withResolved(deser,
                 findContentNullProvider(ctxt, property, deser), unwrapSingle);
     }
 
@@ -261,10 +222,8 @@ public EnumSet<?> deserialize(JsonParser p, DeserializationContext ctxt,
     protected final EnumSet<?> _deserialize(JsonParser p, DeserializationContext ctxt,
             EnumSet result) throws IOException
     {
-        JsonToken t;
-        final TypeDeserializer typeDeser = _valueTypeDeserializer;
-
         try {
+            JsonToken t;
             while ((t = p.nextToken()) != JsonToken.END_ARRAY) {
                 // What to do with nulls? Fail or ignore? Fail, for now (note: would fail if we
                 // passed it to EnumDeserializer, too, but in general nulls should never be passed
@@ -275,10 +234,8 @@ protected final EnumSet<?> _deserialize(JsonParser p, DeserializationContext ctx
                         continue;
                     }
                     value = (Enum<?>) _nullProvider.getNullValue(ctxt);
-                } else if (typeDeser == null) {
-                    value = _enumDeserializer.deserialize(p, ctxt);
                 } else {
-                    value = (Enum<?>) _enumDeserializer.deserializeWithType(p, ctxt, typeDeser);
+                    value = _enumDeserializer.deserialize(p, ctxt);
                 }
                 if (value != null) {
                     result.add(value);

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

@@ -146,9 +146,9 @@ protected String _locateTypeId(JsonParser p, DeserializationContext ctxt) throws
                 }
                 return id;
             }
-             ctxt.reportWrongTokenException(baseType(), JsonToken.START_ARRAY,
-                     "need Array value to contain `As.WRAPPER_ARRAY` type information for class "+baseTypeName());
-             return null;
+            ctxt.reportWrongTokenException(baseType(), JsonToken.START_ARRAY,
+                    "need Array value to contain `As.WRAPPER_ARRAY` type information for class "+baseTypeName());
+            return null;
         }
         // And then type id as a String
         JsonToken t = p.nextToken();

src/main/java/com/fasterxml/jackson/databind/ser/std/CollectionSerializer.java

@@ -2,6 +2,7 @@
 
 import java.io.IOException;
 import java.util.Collection;
+import java.util.EnumSet;
 import java.util.Iterator;
 
 import com.fasterxml.jackson.core.*;
@@ -26,6 +27,15 @@ public class CollectionSerializer
 {
     private static final long serialVersionUID = 1L;
 
+    /**
+     * Flag that indicates that we may need to check for EnumSet dynamically
+     * during serialization: problem being that we can't always do it statically.
+     * But we can figure out when there is a possibility wrt type signature we get.
+     *
+     * @since 2.18.3
+     */
+    private final boolean _maybeEnumSet;
+
     /*
     /**********************************************************
     /* Life-cycle
@@ -38,22 +48,17 @@ public class CollectionSerializer
     public CollectionSerializer(JavaType elemType, boolean staticTyping, TypeSerializer vts,
             JsonSerializer<Object> valueSerializer) {
         super(Collection.class, elemType, staticTyping, vts, valueSerializer);
-    }
-
-    /**
-     * @deprecated since 2.6
-     */
-    @Deprecated // since 2.6
-    public CollectionSerializer(JavaType elemType, boolean staticTyping, TypeSerializer vts,
-            BeanProperty property, JsonSerializer<Object> valueSerializer) {
-        // note: assumption is 'property' is always passed as null
-        this(elemType, staticTyping, vts, valueSerializer);
+        // Unfortunately we can't check for EnumSet statically (if type indicated it,
+        // we'd have constructed `EnumSetSerializer` instead). But we can check that
+        // element type could possibly be an Enum.
+        _maybeEnumSet = elemType.isEnumType() || elemType.isJavaLangObject();
     }
 
     public CollectionSerializer(CollectionSerializer src,
             BeanProperty property, TypeSerializer vts, JsonSerializer<?> valueSerializer,
             Boolean unwrapSingle) {
         super(src, property, vts, valueSerializer, unwrapSingle);
+        _maybeEnumSet = src._maybeEnumSet;
     }
 
     @Override
@@ -120,7 +125,9 @@ public void serializeContents(Collection<?> value, JsonGenerator g, SerializerPr
             return;
         }
         PropertySerializerMap serializers = _dynamicSerializers;
-        final TypeSerializer typeSer = _valueTypeSerializer;
+        // [databind#4849]/[databind#4214]: need to check for EnumSet
+        final TypeSerializer typeSer = (_maybeEnumSet && value instanceof EnumSet<?>)
+                ? null : _valueTypeSerializer;
 
         int i = 0;
         try {
@@ -158,7 +165,9 @@ public void serializeContentsUsing(Collection<?> value, JsonGenerator g, Seriali
     {
         Iterator<?> it = value.iterator();
         if (it.hasNext()) {
-            TypeSerializer typeSer = _valueTypeSerializer;
+            // [databind#4849]/[databind#4214]: need to check for EnumSet
+            final TypeSerializer typeSer = (_maybeEnumSet && value instanceof EnumSet<?>)
+                    ? null : _valueTypeSerializer;
             int i = 0;
             do {
                 Object elem = it.next();

src/main/java/com/fasterxml/jackson/databind/ser/std/EnumSetSerializer.java

@@ -26,7 +26,7 @@ public EnumSetSerializer(EnumSetSerializer src,
 
     @Override
     public EnumSetSerializer _withValueTypeSerializer(TypeSerializer vts) {
-        // no typing for enums (always "hard" type)
+        // no typing for enum elements (always strongly typed), so don't change
         return this;
     }
 
@@ -48,7 +48,7 @@ public boolean hasSingleElement(EnumSet<? extends Enum<?>> value) {
     }
 
     @Override
-    public final void serialize(EnumSet<? extends Enum<?>> value, JsonGenerator gen,
+    public void serialize(EnumSet<? extends Enum<?>> value, JsonGenerator gen,
             SerializerProvider provider) throws IOException
     {
         final int len = value.size();
@@ -70,15 +70,13 @@ public void serializeContents(EnumSet<? extends Enum<?>> value, JsonGenerator ge
             SerializerProvider provider)
         throws IOException
     {
+        gen.assignCurrentValue(value);
         JsonSerializer<Object> enumSer = _elementSerializer;
-        /* Need to dynamically find instance serializer; unfortunately
-         * that seems to be the only way to figure out type (no accessors
-         * to the enum class that set knows)
-         */
+        // Need to dynamically find instance serializer; unfortunately
+        // that seems to be the only way to figure out type (no accessors
+        // to the enum class that set knows)
         for (Enum<?> en : value) {
             if (enumSer == null) {
-                // 12-Jan-2010, tatu: Since enums cannot be polymorphic, let's
-                //   not bother with typed serializer variant here
                 enumSer = provider.findContentValueSerializer(en.getDeclaringClass(), _property);
             }
             enumSer.serialize(en, gen, provider);

src/test/java/com/fasterxml/jackson/databind/ObjectMapperTest.java

@@ -283,7 +283,7 @@ public void jsonMapperRebuildTest()
 
         JsonMapper m3 = m2.rebuild()
                 .propertyNamingStrategy(PropertyNamingStrategies.SNAKE_CASE)
-                .enumNamingStrategy(EnumNamingStrategies.CamelCaseStrategy.INSTANCE)
+                .enumNamingStrategy(EnumNamingStrategies.UPPER_CAMEL_CASE)
                 .enable(MapperFeature.ACCEPT_CASE_INSENSITIVE_ENUMS)
                 .enable(EnumFeature.WRITE_ENUMS_TO_LOWERCASE)
                 .build();

src/test/java/com/fasterxml/jackson/databind/deser/creators/ValueInstantiatorTest.java

@@ -12,7 +12,6 @@
 import com.fasterxml.jackson.databind.exc.InvalidDefinitionException;
 import com.fasterxml.jackson.databind.introspect.AnnotatedWithParams;
 import com.fasterxml.jackson.databind.module.SimpleModule;
-import com.fasterxml.jackson.databind.type.TypeFactory;
 
 import static org.junit.jupiter.api.Assertions.*;