moved applyIndexedObject internal, now invoked inside forObject static factory method

org.springframework.core/src/main/java/org/springframework/core/convert/ConversionException.java

@@ -24,6 +24,7 @@ import org.springframework.core.NestedRuntimeException;
  * @author Keith Donald
  * @since 3.0 
  */
+@SuppressWarnings("serial")
 public abstract class ConversionException extends NestedRuntimeException {
 
 	/**

org.springframework.core/src/main/java/org/springframework/core/convert/ConversionFailedException.java

@@ -25,6 +25,7 @@ import org.springframework.util.ObjectUtils;
  * @author Juergen Hoeller
  * @since 3.0
  */
+@SuppressWarnings("serial")
 public final class ConversionFailedException extends ConversionException {
 
 	private final TypeDescriptor sourceType;

org.springframework.core/src/main/java/org/springframework/core/convert/TypeDescriptor.java

@@ -138,10 +138,11 @@ public class TypeDescriptor {
 			return NULL;
 		}
 		if (object instanceof Collection<?>) {
-			return new TypeDescriptor(object.getClass(), CollectionUtils.findCommonElementType((Collection<?>) object));
+			return new TypeDescriptor(object.getClass(), findCommonElement((Collection<?>) object));
 		}
 		else if (object instanceof Map<?, ?>) {
-			return new TypeDescriptor(object.getClass(), CollectionUtils.findCommonElementType(((Map<?, ?>) object).keySet()), CollectionUtils.findCommonElementType(((Map<?, ?>) object).values()));
+			Map<?, ?> map = (Map<?, ?>) object;
+			return new TypeDescriptor(map.getClass(), findCommonElement(map.keySet()), findCommonElement(map.values()));
 		}
 		else {
 			return valueOf(object.getClass());
@@ -342,37 +343,6 @@ public class TypeDescriptor {
 		return methodParameter;
 	}
 	
-	/**
-	 * Create a copy of this nested type descriptor and apply the specific type information from the indexed value, if necessary.
-	 * Used to support collection and map indexing scenarios, where the indexer has a reference to the indexed type descriptor but needs to ensure its type actually represents the indexed object type.
-	 * This is necessary to support type conversion during collection and map binding operations where generic information may not be available.
-	 */
-	public TypeDescriptor applyIndexedObject(Object object) {
-		if (object == null) {
-			return this;
-		}
-		if (isCollection() && Object.class.equals(getElementType())) {
-			Collection<?> collection = (Collection<?>) object;
-			if (collection.size() > 0) {
-				return new TypeDescriptor(object.getClass(), CollectionUtils.findCommonElementType((Collection<?>) object), methodParameter, field, fieldNestingLevel, annotations);
-			} else {
-				return this;
-			}
-		}
-		else if (isMap() && Object.class.equals(getMapKeyType()) && Object.class.equals(getMapValueType())) {
-			Map<?, ?> map = (Map<?, ?>) object;
-			if (map.size() > 0) {
-				return new TypeDescriptor(object.getClass(), CollectionUtils.findCommonElementType(((Map<?, ?>) object).keySet()),
-						CollectionUtils.findCommonElementType(((Map<?, ?>) object).values()), methodParameter, field, fieldNestingLevel, annotations);
-			} else {
-				return this;
-			}
-		}
-		else {
-			return this;
-		}
-	}
-	
 	// extending Object
 	
 	public boolean equals(Object obj) {
@@ -545,6 +515,20 @@ public class TypeDescriptor {
 		return methodParameter;
 	}
 
+	private static Object findCommonElement(Collection<?> values) {
+		Object candidate = null;
+		for (Object value : values) {
+			if (value != null) {
+				if (candidate == null) {
+					candidate = value;
+				} else if (candidate.getClass() != value.getClass()) {
+					return null;
+				}
+			}
+		}
+		return candidate;
+	}
+	
 	// internal constructors
 
 	private TypeDescriptor() {
@@ -555,46 +539,44 @@ public class TypeDescriptor {
 		this.type = type;
 	}
 
-	private TypeDescriptor(Class<?> collectionType, Class<?> elementType) {
-		this.type = collectionType;
-		if (elementType == null) {
-			elementType = Object.class;
-		}
-		this.elementType = TypeDescriptor.valueOf(elementType);
-	}
-
-	private TypeDescriptor(Class<?> mapType, Class<?> keyType, Class<?> valueType) {
-		this.type = mapType;
-		if (keyType == null) {
-			keyType = Object.class;
-		}
-		if (valueType == null) {
-			valueType = Object.class;
-		}
-		this.mapKeyType = TypeDescriptor.valueOf(keyType);
-		this.mapValueType = TypeDescriptor.valueOf(valueType);
-	}
-
-	private TypeDescriptor(Class<?> collectionType, Class<?> elementType, MethodParameter methodParameter, Field field, int fieldNestingLevel, Annotation[] annotations) {
-		this(collectionType, elementType);
-		this.methodParameter = methodParameter;
-		this.field = field;
-		this.fieldNestingLevel = fieldNestingLevel;
-		this.annotations = annotations;
-	}
-
-	private TypeDescriptor(Class<?> mapType, Class<?> keyType, Class<?> valueType, MethodParameter methodParameter, Field field, int fieldNestingLevel, Annotation[] annotations) {
-		this(mapType, keyType, valueType);
-		this.methodParameter = methodParameter;
-		this.field = field;
-		this.fieldNestingLevel = fieldNestingLevel;
-		this.annotations = annotations;
-	}
-
 	private TypeDescriptor(Class<?> nestedType, Field field, int nestingLevel) {
 		this.type = nestedType;
 		this.field = field;
 		this.fieldNestingLevel = nestingLevel;
 	}
 
+	public TypeDescriptor(Class<?> mapType, Object commonKey, Object commonValue) {
+		this.type = mapType;
+		this.mapKeyType = applyIndexedObject(commonKey);
+		this.mapValueType = applyIndexedObject(commonValue);
+	}
+	
+	public TypeDescriptor(Class<?> collectionType, Object commonElement) {
+		this.type = collectionType;
+		this.elementType = applyIndexedObject(commonElement);
+	}
+
+	private TypeDescriptor applyIndexedObject(Object object) {
+		if (object == null) {
+			return TypeDescriptor.valueOf(Object.class);
+		}
+		if (object instanceof Collection<?>) {
+			Collection<?> collection = (Collection<?>) object;
+			if (collection.size() == 0) {
+				return TypeDescriptor.valueOf(Object.class);
+			}
+			return new TypeDescriptor(object.getClass(), findCommonElement((Collection<?>) object));			
+		}
+		else if (object instanceof Map<?, ?>) {
+			Map<?, ?> map = (Map<?, ?>) object;
+			if (map.size() == 0) {
+				return TypeDescriptor.valueOf(Object.class);				
+			}
+			return new TypeDescriptor(object.getClass(), findCommonElement(map.keySet()), findCommonElement(map.values()));
+		}
+		else {
+			return TypeDescriptor.valueOf(object.getClass());
+		}
+	}
+
 }

org.springframework.core/src/main/java/org/springframework/core/convert/support/ArrayToCollectionConverter.java

@@ -52,12 +52,13 @@ final class ArrayToCollectionConverter implements ConditionalGenericConverter {
 		return this.conversionService.canConvert(sourceType.getElementTypeDescriptor(), targetType.getElementTypeDescriptor());
 	}
 
+	@SuppressWarnings("unchecked")
 	public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
 		if (source == null) {
 			return null;
 		}		
 		int length = Array.getLength(source);
-		Collection target = CollectionFactory.createCollection(targetType.getType(), length);
+		Collection<Object> target = CollectionFactory.createCollection(targetType.getType(), length);
 		for (int i = 0; i < length; i++) {
 			Object sourceElement = Array.get(source, i);
 			Object targetElement = this.conversionService.convert(sourceElement, sourceType.getElementTypeDescriptor(), targetType.getElementTypeDescriptor());

org.springframework.core/src/main/java/org/springframework/core/convert/support/CollectionToArrayConverter.java

@@ -64,7 +64,7 @@ final class CollectionToArrayConverter implements ConditionalGenericConverter {
 		Object array = Array.newInstance(targetType.getElementType(), sourceCollection.size());
 		int i = 0;
 		for (Object sourceElement : sourceCollection) {
-			Object targetElement = this.conversionService.convert(sourceElement, sourceType.getElementTypeDescriptor().applyIndexedObject(sourceElement), targetType.getElementTypeDescriptor());
+			Object targetElement = this.conversionService.convert(sourceElement, sourceType.getElementTypeDescriptor(), targetType.getElementTypeDescriptor());
 			Array.set(array, i++, targetElement);
 		}
 		return array;

org.springframework.core/src/main/java/org/springframework/core/convert/support/CollectionToCollectionConverter.java

@@ -57,14 +57,15 @@ final class CollectionToCollectionConverter implements ConditionalGenericConvert
 		return this.conversionService.canConvert(sourceElementType, targetElementType);
 	}
 	
+	@SuppressWarnings("unchecked")
 	public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
 		if (source == null) {
 			return null;
 		}
 		Collection<?> sourceCollection = (Collection<?>) source;
-		Collection target = CollectionFactory.createCollection(targetType.getType(), sourceCollection.size());
+		Collection<Object> target = CollectionFactory.createCollection(targetType.getType(), sourceCollection.size());
 		for (Object sourceElement : sourceCollection) {
-			Object targetElement = this.conversionService.convert(sourceElement, sourceType.getElementTypeDescriptor().applyIndexedObject(sourceElement), targetType.getElementTypeDescriptor());
+			Object targetElement = this.conversionService.convert(sourceElement, sourceType.getElementTypeDescriptor(), targetType.getElementTypeDescriptor());
 			target.add(targetElement);
 		}
 		return target;

org.springframework.core/src/main/java/org/springframework/core/convert/support/CollectionToObjectConverter.java

@@ -59,7 +59,7 @@ final class CollectionToObjectConverter implements ConditionalGenericConverter {
 			return null;
 		}
 		Object firstElement = sourceCollection.iterator().next();
-		return this.conversionService.convert(firstElement, sourceType.getElementTypeDescriptor().applyIndexedObject(firstElement), targetType);
+		return this.conversionService.convert(firstElement, sourceType.getElementTypeDescriptor(), targetType);
 	}
 
 }

org.springframework.core/src/main/java/org/springframework/core/convert/support/DefaultConversionService.java

@@ -16,9 +16,6 @@
 
 package org.springframework.core.convert.support;
 
-import org.springframework.core.convert.ConversionService;
-import org.springframework.core.convert.converter.ConverterRegistry;
-
 /**
  * A specialization of {@link GenericConversionService} configured by default with
  * converters appropriate for most applications.

org.springframework.core/src/main/java/org/springframework/core/convert/support/GenericConversionService.java

@@ -481,10 +481,10 @@ public class GenericConversionService implements ConversionService, ConverterReg
 
 		private final ConvertiblePair typeInfo;
 
-		private final Converter converter;
+		private final Converter<Object, Object> converter;
 
 		public ConverterAdapter(ConvertiblePair typeInfo, Converter<?, ?> converter) {
-			this.converter = converter;
+			this.converter = (Converter<Object, Object>) converter;
 			this.typeInfo = typeInfo;
 		}
 
@@ -511,10 +511,10 @@ public class GenericConversionService implements ConversionService, ConverterReg
 
 		private final ConvertiblePair typeInfo;
 
-		private final ConverterFactory converterFactory;
+		private final ConverterFactory<Object, Object> converterFactory;
 
 		public ConverterFactoryAdapter(ConvertiblePair typeInfo, ConverterFactory<?, ?> converterFactory) {
-			this.converterFactory = converterFactory;
+			this.converterFactory = (ConverterFactory<Object, Object>) converterFactory;
 			this.typeInfo = typeInfo;
 		}
 

org.springframework.core/src/main/java/org/springframework/core/convert/support/MapToMapConverter.java

@@ -55,6 +55,7 @@ final class MapToMapConverter implements ConditionalGenericConverter {
 		TypeDescriptor targetValueType = targetType.getMapValueTypeDescriptor();
 		if (Object.class.equals(sourceKeyType.getType()) && Object.class.equals(sourceValueType.getType())
 				|| Object.class.equals(targetKeyType.getType()) && Object.class.equals(targetValueType.getType())) {
+			// catches the empty map case
 			return true;
 		}		
 		return this.conversionService.canConvert(sourceType.getMapKeyTypeDescriptor(), targetType.getMapKeyTypeDescriptor()) && 
@@ -78,8 +79,8 @@ final class MapToMapConverter implements ConditionalGenericConverter {
 			for (Map.Entry<Object, Object> entry : sourceMap.entrySet()) {
 				Object sourceKey = entry.getKey();
 				Object sourceValue = entry.getValue();
-				Object targetKey = this.conversionService.convert(sourceKey, sourceType.getMapKeyTypeDescriptor().applyIndexedObject(sourceKey), targetType.getMapKeyTypeDescriptor());
+				Object targetKey = this.conversionService.convert(sourceKey, sourceType.getMapKeyTypeDescriptor(), targetType.getMapKeyTypeDescriptor());
-				Object targetValue = this.conversionService.convert(sourceValue, sourceType.getMapValueTypeDescriptor().applyIndexedObject(sourceValue), targetType.getMapValueTypeDescriptor());
+				Object targetValue = this.conversionService.convert(sourceValue, sourceType.getMapValueTypeDescriptor(), targetType.getMapValueTypeDescriptor());
 				targetMap.put(targetKey, targetValue);
 			}			
 		}

org.springframework.core/src/main/java/org/springframework/core/convert/support/ObjectToCollectionConverter.java

@@ -49,11 +49,12 @@ final class ObjectToCollectionConverter implements ConditionalGenericConverter {
 		return this.conversionService.canConvert(sourceType, targetType.getElementTypeDescriptor());
 	}
 
+	@SuppressWarnings("unchecked")
 	public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
 		if (source == null) {
 			return null;
 		}
-		Collection target = CollectionFactory.createCollection(targetType.getType(), 1);
+		Collection<Object> target = CollectionFactory.createCollection(targetType.getType(), 1);
 		TypeDescriptor elementType = targetType.getElementTypeDescriptor();
 		// Avoid potential recursion...
 		if (!Collection.class.isAssignableFrom(elementType.getType())) {

org.springframework.core/src/main/java/org/springframework/core/convert/support/ObjectToObjectConverter.java

@@ -44,8 +44,8 @@ import org.springframework.util.ReflectionUtils;
 final class ObjectToObjectConverter implements ConditionalGenericConverter {
 
 	public boolean matches(TypeDescriptor sourceType, TypeDescriptor targetType) {
-		Class source = sourceType.getObjectType();
+		Class<?> source = sourceType.getObjectType();
-		Class target = targetType.getObjectType();
+		Class<?> target = targetType.getObjectType();
 		return (!source.equals(target) && hasValueOfMethodOrConstructor(target, source));
 	}
 

org.springframework.core/src/main/java/org/springframework/core/convert/support/PropertyTypeDescriptor.java

@@ -20,11 +20,9 @@ import java.beans.PropertyDescriptor;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
-import java.util.Collection;
 import java.util.LinkedHashMap;
 import java.util.Map;
 
-import org.springframework.core.GenericCollectionTypeResolver;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.util.ReflectionUtils;

org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToCollectionConverter.java

@@ -48,13 +48,14 @@ final class StringToCollectionConverter implements ConditionalGenericConverter {
 		return this.conversionService.canConvert(sourceType, targetType.getElementTypeDescriptor());
 	}
 
+	@SuppressWarnings("unchecked")
 	public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {		
 		if (source == null) {
 			return null;
 		}
 		String string = (String) source;
 		String[] fields = StringUtils.commaDelimitedListToStringArray(string);
-		Collection target = CollectionFactory.createCollection(targetType.getType(), fields.length);
+		Collection<Object> target = CollectionFactory.createCollection(targetType.getType(), fields.length);
 		for (String sourceElement : fields) {
 			Object targetElement = this.conversionService.convert(sourceElement.trim(), sourceType, targetType.getElementTypeDescriptor());
 			target.add(targetElement);

org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToEnumConverterFactory.java

@@ -25,7 +25,7 @@ import org.springframework.core.convert.converter.ConverterFactory;
  * @author Keith Donald
  * @since 3.0
  */
-@SuppressWarnings("unchecked")
+@SuppressWarnings({ "unchecked", "rawtypes" })
 final class StringToEnumConverterFactory implements ConverterFactory<String, Enum> {
 
 	public <T extends Enum> Converter<String, T> getConverter(Class<T> targetType) {

org.springframework.expression/src/main/java/org/springframework/expression/spel/ast/Indexer.java

@@ -93,7 +93,7 @@ public class Indexer extends SpelNodeImpl {
 			Object possiblyConvertedKey = index;
 			possiblyConvertedKey = state.convertValue(index, targetObjectTypeDescriptor.getMapKeyTypeDescriptor());
 			Object o = ((Map<?, ?>) targetObject).get(possiblyConvertedKey);
-			return new TypedValue(o, targetObjectTypeDescriptor.getMapValueTypeDescriptor().applyIndexedObject(o));
+			return new TypedValue(o, targetObjectTypeDescriptor.getMapValueTypeDescriptor());
 		}
 		
 		if (targetObject == null) {
@@ -105,7 +105,7 @@ public class Indexer extends SpelNodeImpl {
 			int idx = (Integer)state.convertValue(index, TypeDescriptor.valueOf(Integer.class));		
 			if (targetObject.getClass().isArray()) {
 				Object arrayElement = accessArrayElement(targetObject, idx);
-				return new TypedValue(arrayElement, targetObjectTypeDescriptor.getElementTypeDescriptor().applyIndexedObject(arrayElement));
+				return new TypedValue(arrayElement, targetObjectTypeDescriptor.getElementTypeDescriptor());
 			} else if (targetObject instanceof Collection) {
 				Collection c = (Collection) targetObject;
 				if (idx >= c.size()) {
@@ -116,7 +116,7 @@ public class Indexer extends SpelNodeImpl {
 				int pos = 0;
 				for (Object o : c) {
 					if (pos == idx) {
-						return new TypedValue(o, targetObjectTypeDescriptor.getElementTypeDescriptor().applyIndexedObject(o));
+						return new TypedValue(o, targetObjectTypeDescriptor.getElementTypeDescriptor());
 					}
 					pos++;
 				}