Fix #4771: Support OBJECT shape for QNAME serialization and deseriali…

…zation. (#4968)

release-notes/VERSION-2.x

@@ -30,6 +30,9 @@ Project: jackson-databind
   Map object is ignored when Map key type not defined
  (reported by @devdanylo)
  (fix by Joo-Hyuk K)
+#4771: `QName` (de)serialization ignores prefix
+ (reported by @jpraet)
+ (fix contributed by @mcvayc)
 #4772: Serialization and deserialization issue of sub-types used with
   `JsonTypeInfo.Id.DEDUCTION` where sub-types are Object and Array
  (reported by Eduard G)

src/main/java/com/fasterxml/jackson/databind/ext/CoreXMLDeserializers.java

@@ -92,16 +92,50 @@ public Std(Class<?> raw, int kind) {
         public Object deserialize(JsonParser p, DeserializationContext ctxt)
             throws IOException
         {
-            // For most types, use super impl; but GregorianCalendar also allows
-            // integer value (timestamp), which needs separate handling
+            // GregorianCalendar also allows integer value (timestamp),
+            // which needs separate handling
             if (_kind == TYPE_G_CALENDAR) {
                 if (p.hasToken(JsonToken.VALUE_NUMBER_INT)) {
                     return _gregorianFromDate(ctxt, _parseDate(p, ctxt));
                 }
             }
+            // QName also allows object value, which needs separate handling
+            if (_kind == TYPE_QNAME) {
+                if (p.hasToken(JsonToken.START_OBJECT)) {
+                    return _parseQNameObject(p, ctxt);
+                }
+            }
             return super.deserialize(p, ctxt);
         }
 
+        private QName _parseQNameObject(JsonParser p, DeserializationContext ctxt)
+            throws IOException
+        {
+            JsonNode tree = ctxt.readTree(p);
+
+            JsonNode localPart = tree.get("localPart");
+            if (localPart == null) {
+                ctxt.reportInputMismatch(this,
+                        "Object value for `QName` is missing required property 'localPart'");
+            }
+
+            if (!localPart.isTextual()) {
+                ctxt.reportInputMismatch(this,
+                        "Object value property 'localPart' for `QName` must be of type STRING, not %s",
+                        localPart.getNodeType());
+            }
+
+            JsonNode namespaceURI = tree.get("namespaceURI");
+            if (namespaceURI != null) {
+                if (tree.has("prefix")) {
+                    JsonNode prefix = tree.get("prefix");
+                    return new QName(namespaceURI.asText(), localPart.asText(), prefix.asText());
+                }
+                return new QName(namespaceURI.asText(), localPart.asText());
+            }
+            return new QName(localPart.asText());
+        }
+
         @Override
         protected Object _deserialize(String value, DeserializationContext ctxt)
             throws IOException

src/main/java/com/fasterxml/jackson/databind/ext/CoreXMLSerializers.java

@@ -7,6 +7,7 @@
 import javax.xml.datatype.XMLGregorianCalendar;
 import javax.xml.namespace.QName;
 
+import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.core.*;
 import com.fasterxml.jackson.core.type.WritableTypeId;
 import com.fasterxml.jackson.databind.*;
@@ -34,9 +35,12 @@ public JsonSerializer<?> findSerializer(SerializationConfig config,
             JavaType type, BeanDescription beanDesc)
     {
         Class<?> raw = type.getRawClass();
-        if (Duration.class.isAssignableFrom(raw) || QName.class.isAssignableFrom(raw)) {
+        if (Duration.class.isAssignableFrom(raw)) {
             return ToStringSerializer.instance;
         }
+        if (QName.class.isAssignableFrom(raw)) {
+            return QNameSerializer.instance;
+        }
         if (XMLGregorianCalendar.class.isAssignableFrom(raw)) {
             return XMLGregorianCalendarSerializer.instance;
         }
@@ -116,4 +120,73 @@ protected Calendar _convert(XMLGregorianCalendar input) {
             return (input == null) ? null : input.toGregorianCalendar();
         }
     }
+
+    /**
+     * @since 2.19
+     */
+    public static class QNameSerializer
+        extends StdSerializer<QName>
+        implements ContextualSerializer
+    {
+        private static final long serialVersionUID = 1L;
+
+        public final static JsonSerializer<?> instance = new QNameSerializer();
+
+        public QNameSerializer() {
+            super(QName.class);
+        }
+
+        @Override
+        public JsonSerializer<?> createContextual(SerializerProvider serializers, BeanProperty property)
+            throws JsonMappingException
+        {
+            JsonFormat.Value format = findFormatOverrides(serializers, property, handledType());
+            if (format != null) {
+                JsonFormat.Shape shape = format.getShape();
+                if (shape == JsonFormat.Shape.OBJECT) {
+                    return this;
+                }
+            }
+            return ToStringSerializer.instance;
+        }
+
+        @Override
+        public void serialize(QName value, JsonGenerator g, SerializerProvider ctxt)
+            throws IOException
+        {
+            g.writeStartObject(value);
+            serializeProperties(value, g, ctxt);
+            g.writeEndObject();
+        }
+
+        @Override
+        public final void serializeWithType(QName value, JsonGenerator g, SerializerProvider ctxt,
+                TypeSerializer typeSer)
+            throws IOException
+        {
+            WritableTypeId typeIdDef = typeSer.writeTypePrefix(g,
+                    typeSer.typeId(value, JsonToken.START_OBJECT));
+            serializeProperties(value, g, ctxt);
+            typeSer.writeTypeSuffix(g, typeIdDef);
+        }
+
+        private void serializeProperties(QName value, JsonGenerator g, SerializerProvider ctxt)
+            throws IOException
+        {
+            g.writeStringField("localPart", value.getLocalPart());
+            if (!value.getNamespaceURI().isEmpty()) {
+                g.writeStringField("namespaceURI", value.getNamespaceURI());
+            }
+            if (!value.getPrefix().isEmpty()) {
+                g.writeStringField("prefix", value.getPrefix());
+            }
+        }
+
+        @Override
+        public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor, JavaType typeHint)
+                throws JsonMappingException {
+            /*JsonObjectFormatVisitor v =*/ visitor.expectObjectFormat(typeHint);
+            // TODO: would need to visit properties too, see `BeanSerializerBase`
+        }
+    }
 }

src/test/java/com/fasterxml/jackson/databind/ext/MiscJavaXMLTypesReadWriteTest.java

@@ -4,7 +4,9 @@
 import javax.xml.namespace.QName;
 import org.junit.jupiter.api.Test;
 
+import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.exc.MismatchedInputException;
 import com.fasterxml.jackson.databind.testutil.DatabindTestUtil;
 import com.fasterxml.jackson.databind.testutil.NoCheckSubTypeValidator;
 import com.fasterxml.jackson.databind.type.TypeFactory;
@@ -34,12 +36,24 @@ public class MiscJavaXMLTypesReadWriteTest
      */
 
     @Test
-    public void testQNameSer() throws Exception
+    public void testQNameSerDefault() throws Exception
     {
         QName qn = new QName("http://abc", "tag", "prefix");
         assertEquals(q(qn.toString()), MAPPER.writeValueAsString(qn));
     }
 
+    @Test
+    public void testQNameSerToObject() throws Exception
+    {
+        QName qn = new QName("http://abc", "tag", "prefix");
+
+        ObjectMapper mapper = jsonMapperBuilder()
+                .withConfigOverride(QName.class, cfg -> cfg.setFormat(JsonFormat.Value.forShape(JsonFormat.Shape.OBJECT)))
+                .build();
+
+        assertEquals(a2q("{'localPart':'tag','namespaceURI':'http://abc','prefix':'prefix'}"), mapper.writeValueAsString(qn));
+    }
+
     @Test
     public void testDurationSer() throws Exception
     {
@@ -121,6 +135,37 @@ public void testQNameDeser() throws Exception
         assertEquals("", qn.getLocalPart());
     }
 
+    @Test
+    public void testQNameDeserFromObject() throws Exception
+    {
+        String qstr = a2q("{'namespaceURI':'http://abc','localPart':'tag','prefix':'prefix'}");
+        // Ok to read with standard ObjectMapper, no `@JsonFormat` needed
+        QName qn = MAPPER.readValue(qstr, QName.class);
+
+        assertEquals("http://abc", qn.getNamespaceURI());
+        assertEquals("tag", qn.getLocalPart());
+        assertEquals("prefix", qn.getPrefix());
+    }
+
+    @Test
+    public void testQNameDeserFail() throws Exception
+    {
+        try {
+            MAPPER.readValue("{}", QName.class);
+            fail("Should not pass");
+        } catch (MismatchedInputException e) {
+            verifyException(e, "Object value for `QName` is missing required property 'localPart'");
+        }
+
+        try {
+            MAPPER.readValue(a2q("{'localPart': 123}"), QName.class);
+            fail("Should not pass");
+        } catch (MismatchedInputException e) {
+            verifyException(e, "Object value property 'localPart'");
+            verifyException(e, "must be of type STRING, not NUMBER");
+        }
+    }
+
     @Test
     public void testXMLGregorianCalendarDeser() throws Exception
     {
@@ -149,7 +194,6 @@ public void testDurationDeser() throws Exception
     /**********************************************************************
      */
 
-
     @Test
     public void testPolymorphicXMLGregorianCalendar() throws Exception
     {

src/test/java/com/fasterxml/jackson/databind/ext/QNameAsObjectReadWrite4771Test.java

@@ -0,0 +1,57 @@
+package com.fasterxml.jackson.databind.ext;
+
+import java.util.stream.Stream;
+import javax.xml.namespace.QName;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.testutil.DatabindTestUtil;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class QNameAsObjectReadWrite4771Test extends DatabindTestUtil
+{
+    private final ObjectMapper MAPPER = newJsonMapper();
+
+    static class BeanWithQName {
+        @JsonFormat(shape = JsonFormat.Shape.OBJECT)
+        public QName qname;
+
+        BeanWithQName() { }
+
+        public BeanWithQName(QName qName) {
+            this.qname = qName;
+        }
+    }
+
+    @ParameterizedTest
+    @MethodSource("provideAllPerumtationsOfQNameConstructor")
+    void testQNameWithObjectSerialization(QName originalQName) throws JsonProcessingException
+    {
+        BeanWithQName bean = new BeanWithQName(originalQName);
+
+        String json = MAPPER.writeValueAsString(bean);
+
+        QName deserializedQName = MAPPER.readValue(json, BeanWithQName.class).qname;
+
+        assertEquals(originalQName.getLocalPart(), deserializedQName.getLocalPart());
+        assertEquals(originalQName.getNamespaceURI(), deserializedQName.getNamespaceURI());
+        assertEquals(originalQName.getPrefix(), deserializedQName.getPrefix());
+    }
+
+    static Stream<Arguments> provideAllPerumtationsOfQNameConstructor()
+    {
+        return Stream.of(
+                Arguments.of(new QName("test-local-part")),
+                Arguments.of(new QName("test-namespace-uri", "test-local-part")),
+                Arguments.of(new QName("test-namespace-uri", "test-local-part", "test-prefix"))
+        );
+    }
+}