Merge branch '2.x' into 3.0

Author: cowtowncoder

release-notes/VERSION

@@ -5,6 +5,10 @@ Version: 3.x (for earlier see VERSION-2.x)
 === Releases === 
 ------------------------------------------------------------------------
 
+3.0.2 (not yet released)
+
+#114: `XmlMapper` does not support `StreamReadFeature.STRICT_DUPLICATE_DETECTION`
+
 3.0.1 (21-Oct-2025)
 
 No changes since 3.0.0

release-notes/VERSION-2.x

@@ -6,7 +6,8 @@ Project: jackson-dataformat-xml
 
 2.21.0 (not yet released)
 
-No changes since 2.20
+#114: `XmlMapper` does not support `StreamReadFeature.STRICT_DUPLICATE_DETECTION`
+ (reported by @cpopp)
 
 2.20.0 (28-Aug-2025)
 

src/main/java/tools/jackson/dataformat/xml/deser/FromXmlParser.java

@@ -18,6 +18,7 @@
 import tools.jackson.core.exc.StreamReadException;
 import tools.jackson.core.io.IOContext;
 import tools.jackson.core.io.NumberInput;
+import tools.jackson.core.json.DupDetector;
 import tools.jackson.core.util.ByteArrayBuilder;
 import tools.jackson.core.util.JacksonFeatureSet;
 import tools.jackson.dataformat.xml.util.CaseInsensitiveNameSet;
@@ -180,7 +181,9 @@ public FromXmlParser(ObjectReadContext readCtxt, IOContext ioCtxt,
     {
         super(readCtxt, ioCtxt, parserFeatures);
         _formatFeatures = xmlFeatures;
-        _streamReadContext = XmlReadContext.createRootContext(-1, -1);
+        DupDetector dups = StreamReadFeature.STRICT_DUPLICATE_DETECTION.enabledIn(parserFeatures)
+            ? DupDetector.rootDetector(this) : null;
+        _streamReadContext = XmlReadContext.createRootContext(dups, -1, -1);
         _xmlTokens = Objects.requireNonNull(tokenStream, "xmlTokenStream cannot be null");
         _cfgNameForTextElement = nameForTextElement;
         final int firstToken;

src/main/java/tools/jackson/dataformat/xml/deser/XmlReadContext.java

@@ -3,8 +3,10 @@
 import java.util.Set;
 
 import tools.jackson.core.*;
+import tools.jackson.core.exc.StreamReadException;
 import tools.jackson.core.io.CharTypes;
 import tools.jackson.core.io.ContentReference;
+import tools.jackson.core.json.DupDetector;
 
 /**
  * Extension of {@link TokenStreamContext}, which implements
@@ -23,6 +25,12 @@ public final class XmlReadContext
 
     protected final XmlReadContext _parent;
 
+    /**
+     * Object used for checking for duplicate field names, if enabled
+     * (null if not enabled)
+     */
+    protected final DupDetector _dups;
+
     // // // Location information (minus source reference)
 
     protected int _lineNr;
@@ -54,18 +62,27 @@ public final class XmlReadContext
     /**********************************************************************
      */
 
-    public XmlReadContext(int type, XmlReadContext parent, int nestingDepth,
+    public XmlReadContext(int type, XmlReadContext parent, DupDetector dups,
+            int nestingDepth,
             int lineNr, int colNr)
     {
         super();
         _type = type;
         _parent = parent;
+        _dups = dups;
         _nestingDepth = nestingDepth;
         _lineNr = lineNr;
         _columnNr = colNr;
         _index = -1;
     }
 
+    @Deprecated // @since 3.0.2
+    public XmlReadContext(int type, XmlReadContext parent, int nestingDepth,
+            int lineNr, int colNr)
+    {
+        this(type, parent, null, nestingDepth, lineNr, colNr);
+    }
+
     protected final void reset(int type, int lineNr, int colNr)
     {
         _type = type;
@@ -76,6 +93,9 @@ protected final void reset(int type, int lineNr, int colNr)
         _currentValue = null;
         _namesToWrap = null;
         // _nestingDepth is fine since reused instance at same nesting level
+        if (_dups != null) {
+            _dups.reset();
+        }
     }
 
     @Override
@@ -94,17 +114,23 @@ public void assignCurrentValue(Object v) {
     /**********************************************************************
      */
 
+    public static XmlReadContext createRootContext(DupDetector dups, int lineNr, int colNr) {
+        return new XmlReadContext(TYPE_ROOT, null, dups, 0, lineNr, colNr);
+    }
+
+    @Deprecated // @since 3.0.2
     public static XmlReadContext createRootContext(int lineNr, int colNr) {
-        return new XmlReadContext(TYPE_ROOT, null, 0, lineNr, colNr);
+        return createRootContext(null, lineNr, colNr);
     }
 
     public final XmlReadContext createChildArrayContext(int lineNr, int colNr)
     {
         ++_index; // not needed for Object, but does not hurt so no need to check curr type
         XmlReadContext ctxt = _child;
         if (ctxt == null) {
-            _child = ctxt = new XmlReadContext(TYPE_ARRAY, this, _nestingDepth+1,
-                    lineNr, colNr);
+            _child = ctxt = new XmlReadContext(TYPE_ARRAY, this,
+                    (_dups == null) ? null : _dups.child(),
+                            _nestingDepth+1, lineNr, colNr);
             return ctxt;
         }
         ctxt.reset(TYPE_ARRAY, lineNr, colNr);
@@ -116,8 +142,9 @@ public final XmlReadContext createChildObjectContext(int lineNr, int colNr)
         ++_index; // not needed for Object, but does not hurt so no need to check curr type
         XmlReadContext ctxt = _child;
         if (ctxt == null) {
-            _child = ctxt = new XmlReadContext(TYPE_OBJECT, this, _nestingDepth+1,
-                    lineNr, colNr);
+            _child = ctxt = new XmlReadContext(TYPE_OBJECT, this,
+                    (_dups == null) ? null : _dups.child(),
+                            _nestingDepth+1, lineNr, colNr);
             return ctxt;
         }
         ctxt.reset(TYPE_OBJECT, lineNr, colNr);
@@ -159,15 +186,25 @@ public final TokenStreamLocation startLocation(ContentReference srcRef) {
     /**
      * Method called to mark start of new value, mostly to update `index`
      * for Array and Root contexts.
-     *
-     * @since 2.12
      */
     public final void valueStarted() {
         ++_index;
     }
 
-    public void setCurrentName(String name) {
+    public void setCurrentName(String name) throws StreamReadException {
         _currentName = name;
+        if (_dups != null) {
+            _checkDup(_dups, name);
+        }
+    }
+
+    private static void _checkDup(DupDetector dd, String name) throws StreamReadException
+    {
+        if (dd.isDup(name)) {
+            Object src = dd.getSource();
+            throw new StreamReadException(((src instanceof JsonParser) ? ((JsonParser) src) : null),
+                    "Duplicate Object property \""+name+"\"");
+        }
     }
 
     public void setNamesToWrap(Set<String> namesToWrap) {
@@ -181,7 +218,7 @@ public boolean shouldWrap(String localName) {
     protected void convertToArray() {
         _type = TYPE_ARRAY;
     }
-    
+
     /*
     /**********************************************************************
     /* Overridden standard methods

src/test/java/tools/jackson/dataformat/xml/deser/StrictDuplicateDetection114Test.java

@@ -0,0 +1,64 @@
+package tools.jackson.dataformat.xml.deser;
+
+import org.junit.jupiter.api.Test;
+
+import tools.jackson.core.StreamReadFeature;
+import tools.jackson.core.exc.StreamReadException;
+import tools.jackson.dataformat.xml.XmlMapper;
+import tools.jackson.dataformat.xml.XmlTestUtil;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Tests for [dataformat-xml#114]: Support for STRICT_DUPLICATE_DETECTION
+ */
+public class StrictDuplicateDetection114Test extends XmlTestUtil
+{
+    public static class TestBean114 {
+        public String field1;
+        public String field2;
+    }
+
+    private final XmlMapper STRICT_MAPPER = XmlMapper.builder()
+            .enable(StreamReadFeature.STRICT_DUPLICATE_DETECTION)
+            .build();
+
+    // [dataformat-xml#114]
+    @Test
+    public void testStrictDuplicateDetectionWithPOJO() throws Exception
+    {
+        // Test XML mapper should also reject duplicates
+        final String xmlWithDup = "<TestBean><field1>value1</field1><field1>value2</field1></TestBean>";
+
+        StreamReadException e = assertThrows(StreamReadException.class, () -> {
+            STRICT_MAPPER.readValue(xmlWithDup, TestBean114.class);
+        });
+        final String MATCH = "Duplicate Object property \"field1\"";
+        assertTrue(e.getMessage().contains(MATCH),
+                "Expected ["+MATCH+"] error, got: " + e.getMessage());
+    }
+
+    @Test
+    public void testNoDuplicatesShouldWork() throws Exception
+    {
+        final String xml = "<TestBean><field1>value1</field1><field2>value2</field2></TestBean>";
+
+        TestBean114 bean = STRICT_MAPPER.readValue(xml, TestBean114.class);
+        assertNotNull(bean);
+        assertEquals("value1", bean.field1);
+        assertEquals("value2", bean.field2);
+    }
+
+    @Test
+    public void testDuplicateDetectionDisabledByDefault() throws Exception
+    {
+        XmlMapper mapper = newMapper(); // default mapper without strict duplicate detection
+
+        // Should allow duplicates by default (last value wins)
+        final String xmlWithDup = "<TestBean><field1>value1</field1><field1>value2</field1></TestBean>";
+
+        TestBean114 bean = mapper.readValue(xmlWithDup, TestBean114.class);
+        assertNotNull(bean);
+        assertEquals("value2", bean.field1); // last value wins
+    }
+}