fix issue FasterXML#205 - do not swallow duplicated elements in xml>object deser

Signed-off-by: joaovarandas <[email protected]>

Author: joaovarandas

src/main/java/com/fasterxml/jackson/dataformat/xml/JacksonXmlModule.java

@@ -4,6 +4,7 @@
 import com.fasterxml.jackson.databind.module.SimpleModule;
 import com.fasterxml.jackson.dataformat.xml.deser.FromXmlParser;
 import com.fasterxml.jackson.dataformat.xml.deser.XmlBeanDeserializerModifier;
+import com.fasterxml.jackson.dataformat.xml.deser.XmlUntypedObjectDeserializer;
 import com.fasterxml.jackson.dataformat.xml.ser.XmlBeanSerializerModifier;
 
 /**
@@ -65,6 +66,9 @@ public void setupModule(SetupContext context)
             XmlMapper m = (XmlMapper) context.getOwner();
             m.setXMLTextElementName(_cfgNameForTextElement);
         }
+        
+        // fix the duplicated elements bug in an untyped Object
+        addDeserializer(Object.class, new XmlUntypedObjectDeserializer());
 
         /* Usually this would be the first call; but here anything added will
          * be stuff user may has added, so do it afterwards instead.

src/main/java/com/fasterxml/jackson/dataformat/xml/deser/XmlUntypedObjectDeserializer.java

@@ -0,0 +1,87 @@
+package com.fasterxml.jackson.dataformat.xml.deser;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.deser.std.UntypedObjectDeserializer;
+
+public class XmlUntypedObjectDeserializer extends UntypedObjectDeserializer {
+
+	@Override
+	@SuppressWarnings("unchecked")
+	protected Object mapObject(JsonParser p, DeserializationContext ctxt) throws IOException {
+        String firstKey;
+
+        JsonToken t = p.getCurrentToken();
+        
+        if (t == JsonToken.START_OBJECT) {
+        	firstKey = p.nextFieldName();
+        } else if (t == JsonToken.FIELD_NAME) {
+        	firstKey = p.getCurrentName();
+        } else {
+            if (t != JsonToken.END_OBJECT) {
+                throw ctxt.mappingException(handledType(), p.getCurrentToken());
+            }
+            firstKey = null;
+        }
+        
+        // empty map might work; but caller may want to modify... so better just give small modifiable
+        LinkedHashMap<String, Object> resultMap = new LinkedHashMap<String, Object>(2);
+        if (firstKey == null) return resultMap; 
+        
+        p.nextToken();
+        resultMap.put(firstKey, deserialize(p, ctxt));
+        
+        
+        // 03-Aug-2016, jpvarandas: handle next objects and create an array
+        Set<String> listKeys = new LinkedHashSet<>();
+        
+        String nextKey;
+        while((nextKey = p.nextFieldName()) != null) {	        	        	
+	        p.nextToken();
+        	if (resultMap.containsKey(nextKey)) {
+	        	Object listObject = resultMap.get(nextKey);
+	        	
+	        	if (!(listObject instanceof List)) {
+	        		listObject = new ArrayList<>();
+	        		((List) listObject).add(resultMap.get(nextKey));
+	        		
+	        		resultMap.put(nextKey, listObject);
+	        	}
+	        	
+	            ((List) listObject).add(deserialize(p, ctxt));
+	            
+	            listKeys.add(nextKey);
+	            
+	        } else {
+	        	resultMap.put(nextKey, deserialize(p, ctxt));
+	        	
+	        }
+        }    
+        
+        /*
+        // if we have more than 1 element type in this root, it
+        // makes sense (semantically) to fix the object name to a nList
+        if (resultMap.keySet().size() > 1 && !listKeys.isEmpty()) {
+        	for(String key: listKeys) {
+        		Object data = resultMap.get(key);        		
+        		resultMap.remove(key);
+        		
+        		resultMap.put(key+"List", data);
+        	}
+        }
+        */
+        
+        return resultMap;
+        
+        
+	}
+
+}

src/test/java/com/fasterxml/jackson/dataformat/xml/stream/XmlParserTest.java

@@ -1,10 +1,16 @@
 package com.fasterxml.jackson.dataformat.xml.stream;
 
-import java.io.*;
-
-import com.fasterxml.jackson.core.*;
+import java.io.IOException;
+import java.io.StringReader;
+import java.io.StringWriter;
+
+import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonToken;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectWriter;
 import com.fasterxml.jackson.dataformat.xml.XmlFactory;
 import com.fasterxml.jackson.dataformat.xml.XmlMapper;
 import com.fasterxml.jackson.dataformat.xml.XmlTestBase;
@@ -21,6 +27,7 @@ public class XmlParserTest extends XmlTestBase
     protected JsonFactory _jsonFactory;
     protected XmlFactory _xmlFactory;
     protected XmlMapper _xmlMapper;
+    protected ObjectWriter _objectWriter;
 
     // let's actually reuse XmlMapper to make things bit faster
     @Override
@@ -29,6 +36,7 @@ public void setUp() throws Exception {
         _jsonFactory = new JsonFactory();
         _xmlFactory = new XmlFactory();
         _xmlMapper = new XmlMapper();
+        _objectWriter = new ObjectMapper().writer();
     }
 
     /*
@@ -57,6 +65,13 @@ public void testSimpleNested() throws Exception
                 _readXmlWriteJson("<root><a><b><c>xyz</c></b></a></root>"));
     }
 
+    public void testDuplicatedElementsSwallowing() throws Exception
+    {
+    	// 04-Aug-2016, jpvarandas: ensure that duplicated elements get wrapped into an array and do not get swallowed (deser and ser)
+        assertEquals("{\"name\":\"John\",\"parent\":[\"Jose\",\"Maria\"],\"dogs\":{\"count\":\"3\",\"dog\":[{\"name\":\"Spike\",\"age\":\"12\"},{\"name\":\"Brutus\",\"age\":\"9\"},{\"name\":\"Bob\",\"age\":\"14\"}]}}",
+        		_readXmlToMapToJson("<person><name>John</name><parent>Jose</parent><parent>Maria</parent><dogs><count>3</count><dog><name>Spike</name><age>12</age></dog><dog><name>Brutus</name><age>9</age></dog><dog><name>Bob</name><age>14</age></dog></dogs></person>"));
+    }
+    
     /**
      * Unit test that verifies that we can write sample document from JSON
      * specification as XML, and read it back in "as JSON", with
@@ -270,4 +285,9 @@ private String _readXmlWriteJson(String xml) throws IOException
         jg.close();
         return w.toString();
     }
+    
+    private String _readXmlToMapToJson(String xml) throws IOException
+    {
+        return _objectWriter.writeValueAsString(_xmlMapper.readValue(xml, Object.class));
+    }
 }