Adding a Case Insensitive DeserializationFeature

src/main/java/com/fasterxml/jackson/databind/MapperFeature.java

@@ -261,7 +261,16 @@ public enum MapperFeature implements ConfigFeature
     /* Name-related features
     /******************************************************
      */
-
+
+    /**
+     * Feature that will allow for more forgiving deserialization of incoming JSON.
+     * If enabled, the bean properties will be matched using their lower-case
+     * equivalents.
+     * <p>
+     * Feature is disabled by default.
+     */
+    ACCEPT_CASE_INSENSITIVE_PROPERTIES(false),
+
     /**
      * Feature that can be enabled to make property names be
      * overridden by wrapper name (usually detected with annotations

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

@@ -29,6 +29,8 @@ public class BeanDeserializerBuilder
 
     final protected boolean _defaultViewInclusion;
 
+    final protected boolean _caseInsensitivePropertyComparison;
+
     /*
     /**********************************************************
     /* Accumulated information about properties
@@ -99,6 +101,7 @@ public BeanDeserializerBuilder(BeanDescription beanDesc,
     { 
         _beanDesc = beanDesc;
         _defaultViewInclusion = config.isEnabled(MapperFeature.DEFAULT_VIEW_INCLUSION);
+        _caseInsensitivePropertyComparison = config.isEnabled(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES);
     }
 
     /**
@@ -109,6 +112,7 @@ protected BeanDeserializerBuilder(BeanDeserializerBuilder src)
     {
         _beanDesc = src._beanDesc;
         _defaultViewInclusion = src._defaultViewInclusion;
+        _caseInsensitivePropertyComparison = src._caseInsensitivePropertyComparison;
 
         // let's make copy of properties
         _properties.putAll(src._properties);
@@ -313,7 +317,7 @@ public JsonPOJOBuilder.Value getBuilderConfig() {
     public JsonDeserializer<?> build()
     {
         Collection<SettableBeanProperty> props = _properties.values();
-        BeanPropertyMap propertyMap = new BeanPropertyMap(props);
+        BeanPropertyMap propertyMap = new BeanPropertyMap(props, _caseInsensitivePropertyComparison);
         propertyMap.assignIndexes();
 
         // view processing must be enabled if:
@@ -378,7 +382,7 @@ public JsonDeserializer<?> buildBuilderBased(JavaType valueType,
         }
         // And if so, we can try building the deserializer
         Collection<SettableBeanProperty> props = _properties.values();
-        BeanPropertyMap propertyMap = new BeanPropertyMap(props);
+        BeanPropertyMap propertyMap = new BeanPropertyMap(props, _caseInsensitivePropertyComparison);
         propertyMap.assignIndexes();
 
         boolean anyViews = !_defaultViewInclusion;

src/main/java/com/fasterxml/jackson/databind/deser/impl/BeanPropertyMap.java

@@ -28,6 +28,8 @@ public final class BeanPropertyMap
     private final int _hashMask;
 
     private final int _size;
+
+    private final boolean _caseInsensitivePropertyComparison;
 
     /**
      * Counter we use to keep track of insertion order of properties
@@ -38,26 +40,28 @@ public final class BeanPropertyMap
      */
     private int _nextBucketIndex = 0;
 
-    public BeanPropertyMap(Collection<SettableBeanProperty> properties)
+    public BeanPropertyMap(Collection<SettableBeanProperty> properties, boolean caseInsensitivePropertyComparison)
     {
+        _caseInsensitivePropertyComparison = caseInsensitivePropertyComparison;
         _size = properties.size();
         int bucketCount = findSize(_size);
         _hashMask = bucketCount-1;
         Bucket[] buckets = new Bucket[bucketCount];
         for (SettableBeanProperty property : properties) {
-            String key = property.getName();
+            String key = getPropertyName(property);
             int index = key.hashCode() & _hashMask;
             buckets[index] = new Bucket(buckets[index], key, property, _nextBucketIndex++);
         }
         _buckets = buckets;
     }
 
-    private BeanPropertyMap(Bucket[] buckets, int size, int index)
+    private BeanPropertyMap(Bucket[] buckets, int size, int index, boolean caseInsensitivePropertyComparison)
     {
         _buckets = buckets;
         _size = size;
         _hashMask = buckets.length-1;
         _nextBucketIndex = index;
+        _caseInsensitivePropertyComparison = caseInsensitivePropertyComparison;
     }
 
     /**
@@ -75,20 +79,20 @@ public BeanPropertyMap withProperty(SettableBeanProperty newProperty)
         final int bcount = _buckets.length;
         Bucket[] newBuckets = new Bucket[bcount];
         System.arraycopy(_buckets, 0, newBuckets, 0, bcount);
-        final String propName = newProperty.getName();
+        final String propName = getPropertyName(newProperty);
         // and then see if it's add or replace:
-        SettableBeanProperty oldProp = find(newProperty.getName());
+        SettableBeanProperty oldProp = find(propName);
         if (oldProp == null) { // add
             // first things first: add or replace?
     	        // can do a straight copy, since all additions are at the front
     	        // and then insert the new property:
     	        int index = propName.hashCode() & _hashMask;
     	        newBuckets[index] = new Bucket(newBuckets[index],
     	                propName, newProperty, _nextBucketIndex++);
-    	        return new BeanPropertyMap(newBuckets, _size+1, _nextBucketIndex);
+    	        return new BeanPropertyMap(newBuckets, _size+1, _nextBucketIndex, _caseInsensitivePropertyComparison);
         }
         // replace: easy, close + replace
-        BeanPropertyMap newMap = new BeanPropertyMap(newBuckets, bcount, _nextBucketIndex);
+        BeanPropertyMap newMap = new BeanPropertyMap(newBuckets, bcount, _nextBucketIndex, _caseInsensitivePropertyComparison);
         newMap.replace(newProperty);
         return newMap;
     }
@@ -120,7 +124,7 @@ public BeanPropertyMap renameAll(NameTransformer transformer)
             newProps.add(prop);
         }
         // should we try to re-index? Ordering probably changed but called probably doesn't want changes...
-        return new BeanPropertyMap(newProps);
+        return new BeanPropertyMap(newProps, _caseInsensitivePropertyComparison);
     }
 
     public BeanPropertyMap assignIndexes()
@@ -146,6 +150,12 @@ private final static int findSize(int size)
         }
         return result;
     }
+
+    // Confining this case insensitivity to this function (and the find method) in case we want to
+    // apply a particular locale to the lower case function.  For now, using the default.
+    private String getPropertyName(SettableBeanProperty prop) {
+    	return _caseInsensitivePropertyComparison ? prop.getName().toLowerCase() : prop.getName();
+    }
 
     /*
     /**********************************************************
@@ -216,6 +226,11 @@ public SettableBeanProperty find(String key)
         if (key == null) {
             throw new IllegalArgumentException("Can not pass null property name");
         }
+
+        if (_caseInsensitivePropertyComparison) {
+        	key = key.toLowerCase();
+        }
+
         int index = key.hashCode() & _hashMask;
         Bucket bucket = _buckets[index];
         // Let's unroll first lookup since that is null or match in 90+% cases
@@ -257,7 +272,7 @@ public SettableBeanProperty find(int propertyIndex)
      */
     public void replace(SettableBeanProperty property)
     {
-        String name = property.getName();
+        String name = getPropertyName(property);
         int index = name.hashCode() & (_buckets.length-1);
 
         /* This is bit tricky just because buckets themselves
@@ -291,7 +306,7 @@ public void replace(SettableBeanProperty property)
     public void remove(SettableBeanProperty property)
     {
         // Mostly this is the same as code with 'replace', just bit simpler...
-        String name = property.getName();
+        String name = getPropertyName(property);
         int index = name.hashCode() & (_buckets.length-1);
         Bucket tail = null;
         boolean found = false;

src/test/java/com/fasterxml/jackson/databind/deser/TestBeanDeserializer.java

@@ -296,6 +296,33 @@ public void testPOJOFromEmptyArray() throws Exception
         Bean result = r.readValue(JSON);
         assertNull(result);
     }
+
+    // [Databind#566]
+    public void testCaseInsensitiveDeserialization() throws Exception
+    {
+    	final String JSON = "{\"Value1\" : {\"nAme\" : \"fruit\", \"vALUe\" : \"apple\"}, \"valUE2\" : {\"NAME\" : \"color\", \"value\" : \"red\"}}";
+
+        // first, verify default settings which do not accept improper case
+        ObjectMapper mapper = new ObjectMapper();
+        assertFalse(mapper.isEnabled(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES));
+
+        try {
+            mapper.readValue(JSON, Issue476Bean.class);
+
+            fail("Should not accept improper case properties by default");
+        } catch (JsonProcessingException e) {
+            verifyException(e, "Unrecognized field");
+            assertValidLocation(e.getLocation());
+        }
+
+        // Definitely not OK to enable dynamically - the BeanPropertyMap (which is the consumer of this particular feature) gets cached.
+        mapper = new ObjectMapper();
+        mapper.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true);
+        ObjectReader r = mapper.reader(Issue476Bean.class);
+        Issue476Bean result = r.readValue(JSON);
+        assertEquals(result.value1.name, "fruit");
+        assertEquals(result.value1.value, "apple");
+    }
 
     // [Issue#120]
     public void testModifyArrayDeserializer() throws Exception