Fix #665: @JacksonXmlProperty with Records (#818)

Author: cowtowncoder

release-notes/CREDITS

@@ -70,6 +70,11 @@ Severin Kistler (@kistlers)
    `java.util.Map`) fails
   (3.2.0)
 
+Alex Olson (@alexkolson)
+ * Reported #665: `@JacksonXmlProperty` appears to behave differently than
+   `@JsonProperty` when used on java records
+  (3.2.0)
+
 Simon Cockx (@SimonCockx)
  * Reported #762: Unwrapping lists does not work inside `@JsonUnwrapped`
   (3.2.0)

release-notes/VERSION

@@ -48,11 +48,15 @@ Version: 3.x (for earlier see VERSION-2.x)
   `java.util.Map`) fails
  (reported by Severin K)
  (fix by Christopher M)
+#665: `@JacksonXmlProperty` appears to behave differently than
+  `@JsonProperty` when used on java records
+ (reported by Alex O)
+ (fix by @cowtowncoder, w/ Claude code)
 #735: Java Record with `@JacksonXmlText` stopped working with 2.18
  (reported by @akastyka))
  (fix by Christopher M)
 #762: Unwrapping lists does not work inside `@JsonUnwrapped`
- (reported by Simon C) 
+ (reported by Simon C)
  (fix by @cowtowncoder, w/ Claude code)
 #767: Unwrapped lists cannot be deserialized when using
   `JsonTypeInfo.As.EXISTING_PROPERTY`

src/main/java/tools/jackson/dataformat/xml/JacksonXmlAnnotationIntrospector.java

@@ -26,7 +26,7 @@ public class JacksonXmlAnnotationIntrospector
     @SuppressWarnings("unchecked")
     private final static Class<? extends Annotation>[] ANNOTATIONS_TO_INFER_XML_PROP =
             (Class<? extends Annotation>[]) new Class<?>[] {
-        JacksonXmlText.class, JacksonXmlElementWrapper.class
+        JacksonXmlProperty.class, JacksonXmlText.class, JacksonXmlElementWrapper.class
     };
 
     /**
@@ -243,7 +243,13 @@ protected PropertyName _findXmlName(Annotated a)
     {
         JacksonXmlProperty pann = _findAnnotation(a, JacksonXmlProperty.class);
         if (pann != null) {
-            return PropertyName.construct(pann.localName(), pann.namespace());
+            // [dataformat-xml#665]: empty localName should not produce an
+            //   empty-string PropertyName (causes "Duplicate creator property"
+            //   on records); return null so that the implicit name is used.
+            String localName = pann.localName();
+            if (localName != null && !localName.isEmpty()) {
+                return PropertyName.construct(localName, pann.namespace());
+            }
         }
         return null;
     }

src/test/java/tools/jackson/dataformat/xml/deser/records/XmlRecordDeser665Test.java

@@ -0,0 +1,47 @@
+package tools.jackson.dataformat.xml.deser.records;
+
+import org.junit.jupiter.api.Test;
+
+import tools.jackson.dataformat.xml.*;
+import tools.jackson.dataformat.xml.annotation.JacksonXmlProperty;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+// [dataformat-xml#665]: @JacksonXmlProperty without localName on records
+//   should not cause "Duplicate creator property" error
+public class XmlRecordDeser665Test extends XmlTestUtil
+{
+    // Bare @JacksonXmlProperty (no arguments) on a record — was failing
+    record SimpleRecord(@JacksonXmlProperty String name, String value) {}
+
+    // @JacksonXmlProperty(isAttribute=true) without localName — the main use case
+    record AttributeRecord(@JacksonXmlProperty(isAttribute = true) String id, String name) {}
+
+    private final XmlMapper MAPPER = newMapper();
+
+    @Test
+    public void testBareAnnotationOnRecord() throws Exception {
+        String xml = "<SimpleRecord><name>test</name><value>val</value></SimpleRecord>";
+        SimpleRecord result = MAPPER.readValue(xml, SimpleRecord.class);
+        assertEquals("test", result.name());
+        assertEquals("val", result.value());
+    }
+
+    @Test
+    public void testIsAttributeWithoutLocalNameOnRecord() throws Exception {
+        String xml = "<AttributeRecord id='123'><name>test</name></AttributeRecord>";
+        AttributeRecord result = MAPPER.readValue(xml, AttributeRecord.class);
+        assertEquals("123", result.id());
+        assertEquals("test", result.name());
+    }
+
+    // Verify serialization round-trip works too
+    @Test
+    public void testSerializationRoundTrip() throws Exception {
+        AttributeRecord original = new AttributeRecord("123", "test");
+        String xml = MAPPER.writeValueAsString(original);
+        AttributeRecord result = MAPPER.readValue(xml, AttributeRecord.class);
+        assertEquals(original.id(), result.id());
+        assertEquals(original.name(), result.name());
+    }
+}