super converter implementation

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

@@ -16,7 +16,7 @@
 package org.springframework.core.convert;
 
 /**
- * A command object that is parameterized with the information necessary to perform a conversion of a source input to a
+ * A command parameterized with the information necessary to perform a conversion of a source input to a
  * target output. Encapsulates knowledge about how to convert source objects to a specific target type using a specific
  * converter.
  * 
@@ -25,20 +25,19 @@ package org.springframework.core.convert;
 public interface ConversionExecutor<S, T> {
 
 	/**
-	 * Returns the source class of conversions performed by this executor.
+	 * The type this executor converts from.
-	 * @return the source class
 	 */
 	public Class<S> getSourceClass();
 
 	/**
-	 * Returns the target class of conversions performed by this executor.
+	 * The type this executor converts to.
-	 * @return the target class
+s	 */
-	 */
 	public Class<T> getTargetClass();
 
 	/**
-	 * Execute the conversion for the provided source object.
+	 * Convert the source to T.
-	 * @param source the source object to convert
+	 * @param source the source to convert
+	 * @throws ConversionExecutionException if an exception occurs during type conversion
 	 */
 	public T execute(S source) throws ConversionExecutionException;
 

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

@@ -26,7 +26,7 @@ package org.springframework.core.convert;
 public interface ConversionService {
 
 	/**
-	 * Convert the source object to <code>targetClass</code>
+	 * Convert the source to target class T.
 	 * @param source the source to convert from (may be null)
 	 * @param targetClass the target class to convert to
 	 * @return the converted object, an instance of the <code>targetClass</code>, or <code>null</code> if a null source
@@ -39,7 +39,7 @@ public interface ConversionService {
 			ConversionException;
 
 	/**
-	 * Convert the source object to <code>targetClass</code> using a custom converter.
+	 * Convert the source to target class T with a custom converter.
 	 * @param converterId the id of the custom converter, which must be registered with this conversion service and
 	 * capable of converting to the targetClass
 	 * @param source the source to convert from (may be null)
@@ -54,7 +54,7 @@ public interface ConversionService {
 			throws ConversionExecutorNotFoundException, ConversionException;
 
 	/**
-	 * Get a ConversionExecutor capable of converting objects from <code>sourceClass</code> to <code>targetClass</code>.
+	 * Get a ConversionExecutor that converts objects from S to T.
 	 * The returned ConversionExecutor is thread-safe and may safely be cached for later use by client code.
 	 * @param sourceClass the source class to convert from (required)
 	 * @param targetClass the target class to convert to (required)
@@ -65,9 +65,8 @@ public interface ConversionService {
 			throws ConversionExecutorNotFoundException;
 
 	/**
-	 * Get a ConversionExecutor that uses a custom converter to capable convert objects from <code>sourceClass</code> to
+	 * Get a ConversionExecutor that that converts objects from S to T with a custom converter.
-	 * <code>targetClass</code>. The returned ConversionExecutor is thread-safe and may safely be cached for use in
+	 * The returned ConversionExecutor is thread-safe and may safely be cached for use in client code.
-	 * client code.
 	 * @param converterId the id of the custom converter, which must be registered with this conversion service and
 	 * capable of converting from sourceClass to targetClass (required)
 	 * @param sourceClass the source class to convert from (required)
@@ -79,9 +78,8 @@ public interface ConversionService {
 			Class<T> targetClass) throws ConversionExecutorNotFoundException;
 
 	/**
-	 * Lookup a class by its well-known alias. For example, <code>long</code> for <code>java.lang.Long</code>
+	 * Get a class by its alias.
-	 * @param alias the class alias
+	 * @return the class, or <code>null</code> if no such alias exists
-	 * @return the class, or <code>null</code> if no alias exists
 	 */
 	public Class<?> getClassForAlias(String alias);
 

org.springframework.core/src/main/java/org/springframework/core/convert/converter/Converter.java

@@ -19,7 +19,7 @@ import org.springframework.core.convert.ConversionException;
 import org.springframework.core.convert.ConversionService;
 
 /**
- * A converter converts a source object of type S to a target type of type T and back.
+ * A converter converts a source object of type S to a target of type T and back.
  * <p>
  * Implementations of this interface are thread-safe and can be shared. Converters are typically registered with and
  * accessed through a {@link ConversionService}.
@@ -29,7 +29,7 @@ import org.springframework.core.convert.ConversionService;
 public interface Converter<S, T> {
 
 	/**
-	 * Convert the source S to target type T.
+	 * Convert the source of type S to target type T.
 	 * @param source the source object to convert, which must be an instance of S
 	 * @return the converted object, which must be an instance of T
 	 * @throws Exception an exception occurred performing the conversion; may be any checked exception, the conversion
@@ -39,7 +39,7 @@ public interface Converter<S, T> {
 	public T convert(S source) throws Exception;
 
 	/**
-	 * Convert the target T back to source type S.
+	 * Convert the target of type T back to source type S.
 	 * @param target the target object to convert, which must be an instance of T
 	 * @return the converted object, which must be an instance of S
 	 * @throws Exception an exception occurred performing the conversion; may be any checked exception, the conversion

org.springframework.core/src/main/java/org/springframework/core/convert/converter/NumberToNumber.java

@@ -37,12 +37,8 @@ import org.springframework.util.NumberUtils;
  */
 public class NumberToNumber implements SuperConverter<Number, Number> {
 
-	public <N extends Number> N convert(Number source, Class<N> targetClass) throws Exception {
+	public <RT extends Number> RT convert(Number source, Class<RT> targetClass) throws Exception {
 		return NumberUtils.convertNumberToTargetClass(source, targetClass);
 	}
 
-	public Number convertBack(Number target) throws Exception {
-		return target;
-	}
-
 }

org.springframework.core/src/main/java/org/springframework/core/convert/converter/StringToEnum.java

@@ -16,19 +16,19 @@
 package org.springframework.core.convert.converter;
 
 /**
- * Converts from a String to Enum using {@link Enum#valueOf(Class, String)}.
+ * Converts a String to a Enum using {@link Enum#valueOf(Class, String)}.
  * 
  * @author Keith Donald
  */
 @SuppressWarnings("unchecked")
-public class StringToEnum implements SuperConverter<String, Enum> {
+public class StringToEnum implements SuperTwoWayConverter<String, Enum> {
 
-	public <E extends Enum> E convert(String source, Class<E> targetClass) throws Exception {
+	public <RT extends Enum> RT convert(String source, Class<RT> targetClass) throws Exception {
 		return Enum.valueOf(targetClass, source);
 	}
 
-	public String convertBack(Enum target) throws Exception {
+	public <RS extends String> RS convertBack(Enum target, Class<RS> sourceClass) throws Exception {
-		return target.name();
+		return (RS) target.name();
 	}
 
 }

org.springframework.core/src/main/java/org/springframework/core/convert/converter/SuperConverter.java

@@ -19,8 +19,7 @@ import org.springframework.core.convert.ConversionException;
 import org.springframework.core.convert.ConversionService;
 
 /**
- * A super converter converts a source object of type S to a target type of type AT and back, where AT is equal to or a
+ * A super converter converts a source object of type S to a target of class hierarchy T.
- * subclass of T, T being the "super" target type.  This allows a single converter to convert to objects that are part of a common class hierarchy.
  * <p>
  * Implementations of this interface are thread-safe and can be shared. Converters are typically registered with and
  * accessed through a {@link ConversionService}.
@@ -30,25 +29,14 @@ import org.springframework.core.convert.ConversionService;
 public interface SuperConverter<S, T> {
 
 	/**
-	 * Convert the source S to an instance of AT.
+	 * Convert the source of type S to an instance of type RT.
-	 * @param source the source object to convert, which must be an instance of S
+	 * @param source the source object to convert, whose class must be equal to or a subclass of S
-	 * @param actualTargetClass the actual target class to convert to (AT), which must be equal to or a specialization
+	 * @param targetClass the requested target class to convert to (RT), which must be equal to T or extend from T
-	 * of T.
+	 * @return the converted object, which must be an instance of RT
-	 * @return the converted object, which must be an instance of AT
 	 * @throws Exception an exception occurred performing the conversion; may be any checked exception, the conversion
 	 * system will handle wrapping the failure in a {@link ConversionException} that provides a consistent type
 	 * conversion error context
 	 */
-	public <AT extends T> AT convert(S source, Class<AT> actualTargetClass) throws Exception;
+	public <RT extends T> RT convert(S source, Class<RT> targetClass) throws Exception;
-
-	/**
-	 * Convert the target T to an instance of S.
-	 * @param target the target object to convert, which must be an instance of T.
-	 * @return the converted object, which must be an instance of S.
-	 * @throws Exception an exception occurred performing the conversion; may be any checked exception, the conversion
-	 * system will handle wrapping the failure in a {@link ConversionException} that provides a consistent type
-	 * conversion error context
-	 */
-	public S convertBack(T target) throws Exception;
 
 }

org.springframework.core/src/main/java/org/springframework/core/convert/converter/SuperTwoWayConverter.java

@@ -0,0 +1,27 @@
+package org.springframework.core.convert.converter;
+
+import org.springframework.core.convert.ConversionException;
+import org.springframework.core.convert.ConversionService;
+
+/**
+ * A super converter that can also convert a target object of type T to a source of class hierarchy S.
+ * <p>
+ * Implementations of this interface are thread-safe and can be shared. Converters are typically registered with and
+ * accessed through a {@link ConversionService}.
+ * </p>
+ * @author Keith Donald
+ */
+public interface SuperTwoWayConverter<S, T> extends SuperConverter<S, T> {
+
+	/**
+	 * Convert the target of type T to an instance of S.
+	 * @param target the target object to convert, whose class must be equal to or a subclass of T
+	 * @param sourceClass the requested source class to convert to, which must be equal to S or extend from S
+	 * @return the converted object, which must be an instance of S
+	 * @throws Exception an exception occurred performing the conversion; may be any checked exception, the conversion
+	 * system will handle wrapping the failure in a {@link ConversionException} that provides a consistent type
+	 * conversion error context
+	 */
+	public <RS extends S> RS convertBack(T target, Class<RS> sourceClass) throws Exception;
+
+}

org.springframework.core/src/main/java/org/springframework/core/convert/converter/SuperTwoWayConverterConverter.java

@@ -0,0 +1,31 @@
+package org.springframework.core.convert.converter;
+
+/**
+ * Adapts a {@link SuperTwoWayConverter} to the {@link Converter} interface in a type safe way. This adapter is useful
+ * for applying more general {@link SuperConverter} logic to a specific source/target class pair.
+ */
+@SuppressWarnings("unchecked")
+public class SuperTwoWayConverterConverter<S, T> implements Converter<S, T> {
+
+	private SuperTwoWayConverter superConverter;
+
+	private Class sourceClass;
+
+	private Class targetClass;
+
+	public <SCS, SCT> SuperTwoWayConverterConverter(SuperTwoWayConverter<SCS, SCT> superConverter,
+			Class<? extends SCS> sourceClass, Class<? extends SCT> targetClass) {
+		this.superConverter = superConverter;
+		this.sourceClass = sourceClass;
+		this.targetClass = targetClass;
+	}
+
+	public T convert(S source) throws Exception {
+		return (T) superConverter.convert(source, targetClass);
+	}
+
+	public S convertBack(T target) throws Exception {
+		return (S) superConverter.convertBack(target, sourceClass);
+	}
+
+}

org.springframework.core/src/main/java/org/springframework/core/convert/service/ArrayToArray.java

@@ -53,18 +53,7 @@ class ArrayToArray implements SuperConverter {
 		this.elementConverter = elementConverter;
 	}
 
-	public Class getSourceClass() {
-		return Object[].class;
-	}
-
-	public Class getSuperTargetClass() {
-		return Object[].class;
-	}
-
 	public Object convert(Object source, Class targetClass) throws Exception {
-		if (source == null) {
-			return null;
-		}
 		Class sourceComponentType = source.getClass().getComponentType();
 		Class targetComponentType = targetClass.getComponentType();
 		int length = Array.getLength(source);
@@ -77,10 +66,6 @@ class ArrayToArray implements SuperConverter {
 		return targetArray;
 	}
 
-	public Object convertBack(Object target) throws Exception {
-		throw new UnsupportedOperationException("Not supported");
-	}
-
 	private ConversionExecutor getElementConverter(Class sourceComponentType, Class targetComponentType) {
 		if (elementConverter != null) {
 			return elementConverter;

org.springframework.core/src/main/java/org/springframework/core/convert/service/ArrayToCollection.java

@@ -17,19 +17,13 @@ package org.springframework.core.convert.service;
 
 import java.lang.reflect.Array;
 import java.lang.reflect.Constructor;
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Set;
-import java.util.SortedSet;
-import java.util.TreeSet;
 
 import org.springframework.core.GenericCollectionTypeResolver;
 import org.springframework.core.convert.ConversionExecutor;
 import org.springframework.core.convert.ConversionService;
-import org.springframework.core.convert.converter.SuperConverter;
+import org.springframework.core.convert.converter.SuperTwoWayConverter;
 
 /**
  * Special converter that converts from a source array to a target collection. Supports the selection of an
@@ -45,7 +39,7 @@ import org.springframework.core.convert.converter.SuperConverter;
  * @author Keith Donald
  */
 @SuppressWarnings("unchecked")
-class ArrayToCollection implements SuperConverter {
+class ArrayToCollection implements SuperTwoWayConverter {
 
 	private ConversionService conversionService;
 
@@ -69,11 +63,8 @@ class ArrayToCollection implements SuperConverter {
 	}
 
 	public Object convert(Object source, Class targetClass) throws Exception {
-		if (source == null) {
+		Class implClass = CollectionConversionUtils.getImpl(targetClass);
-			return null;
+		Constructor constructor = implClass.getConstructor((Class[]) null);
-		}
-		Class collectionImplClass = getCollectionImplClass(targetClass);
-		Constructor constructor = collectionImplClass.getConstructor((Class[]) null);
 		Collection collection = (Collection) constructor.newInstance((Object[]) null);
 		ConversionExecutor converter = getArrayElementConverter(source, targetClass);
 		int length = Array.getLength(source);
@@ -87,16 +78,10 @@ class ArrayToCollection implements SuperConverter {
 		return collection;
 	}
 
-	public Object convertBack(Object target) throws Exception {
-		throw new UnsupportedOperationException("Should never be called");
-	}
-
 	public Object convertBack(Object target, Class sourceClass) throws Exception {
-		if (target == null) {
-			return null;
-		}
 		Collection collection = (Collection) target;
-		Object array = Array.newInstance(sourceClass.getComponentType(), collection.size());
+		Class elementType = sourceClass.getComponentType();
+		Object array = Array.newInstance(elementType, collection.size());
 		int i = 0;
 		for (Iterator it = collection.iterator(); it.hasNext(); i++) {
 			Object value = it.next();
@@ -105,8 +90,7 @@ class ArrayToCollection implements SuperConverter {
 				if (elementConverter != null) {
 					converter = elementConverter;
 				} else {
-					converter = conversionService.getConversionExecutor(value.getClass(), sourceClass
+					converter = conversionService.getConversionExecutor(value.getClass(), elementType);
-							.getComponentType());
 				}
 				value = converter.execute(value);
 			}
@@ -115,22 +99,6 @@ class ArrayToCollection implements SuperConverter {
 		return array;
 	}
 
-	private Class getCollectionImplClass(Class targetClass) {
-		if (targetClass.isInterface()) {
-			if (List.class.equals(targetClass)) {
-				return ArrayList.class;
-			} else if (Set.class.equals(targetClass)) {
-				return LinkedHashSet.class;
-			} else if (SortedSet.class.equals(targetClass)) {
-				return TreeSet.class;
-			} else {
-				throw new IllegalArgumentException("Unsupported collection interface [" + targetClass.getName() + "]");
-			}
-		} else {
-			return targetClass;
-		}
-	}
-
 	private ConversionExecutor getArrayElementConverter(Object source, Class targetClass) {
 		if (elementConverter != null) {
 			return elementConverter;

org.springframework.core/src/main/java/org/springframework/core/convert/service/CollectionConversionUtils.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2004-2009 the original author or authors.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.core.convert.service;
+
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
+
+class CollectionConversionUtils {
+
+	static Class<?> getImpl(Class<?> targetClass) {
+		if (targetClass.isInterface()) {
+			if (List.class.equals(targetClass)) {
+				return ArrayList.class;
+			} else if (Set.class.equals(targetClass)) {
+				return LinkedHashSet.class;
+			} else if (SortedSet.class.equals(targetClass)) {
+				return TreeSet.class;
+			} else {
+				throw new IllegalArgumentException("Unsupported collection interface [" + targetClass.getName() + "]");
+			}
+		} else {
+			return targetClass;
+		}
+	}
+
+}

org.springframework.core/src/main/java/org/springframework/core/convert/service/CollectionToCollection.java

@@ -15,14 +15,8 @@
  */
 package org.springframework.core.convert.service;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Set;
-import java.util.SortedSet;
-import java.util.TreeSet;
 
 import org.springframework.core.GenericCollectionTypeResolver;
 import org.springframework.core.convert.ConversionExecutor;
@@ -35,7 +29,7 @@ import org.springframework.core.convert.converter.SuperConverter;
  * @author Keith Donald
  */
 @SuppressWarnings("unchecked")
-class CollectionToCollection implements SuperConverter {
+class CollectionToCollection implements SuperConverter<Collection, Collection> {
 
 	private ConversionService conversionService;
 
@@ -58,21 +52,10 @@ class CollectionToCollection implements SuperConverter {
 		this.elementConverter = elementConverter;
 	}
 
-	public Class getSourceClass() {
+	public Collection convert(Collection source, Class targetClass) throws Exception {
-		return Collection.class;
+		Class implClass = CollectionConversionUtils.getImpl(targetClass);
-	}
+		Collection targetCollection = (Collection) implClass.getConstructor((Class[]) null)
-
+				.newInstance((Object[]) null);
-	public Class getSuperTargetClass() {
-		return Collection.class;
-	}
-
-	public Object convert(Object source, Class targetClass) throws Exception {
-		if (source == null) {
-			return null;
-		}
-		Class targetCollectionImpl = getCollectionImplClass(targetClass);
-		Collection targetCollection = (Collection) targetCollectionImpl.getConstructor((Class[]) null).newInstance(
-				(Object[]) null);
 		ConversionExecutor elementConverter = getElementConverter(source, targetClass);
 		Collection sourceCollection = (Collection) source;
 		Iterator it = sourceCollection.iterator();
@@ -86,27 +69,6 @@ class CollectionToCollection implements SuperConverter {
 		return targetCollection;
 	}
 
-	public Object convertBack(Object target) throws Exception {
-		throw new UnsupportedOperationException("Not supported");
-	}
-
-	// this code is duplicated in ArrayToCollection.java and ObjectToCollection too
-	private Class getCollectionImplClass(Class targetClass) {
-		if (targetClass.isInterface()) {
-			if (List.class.equals(targetClass)) {
-				return ArrayList.class;
-			} else if (Set.class.equals(targetClass)) {
-				return LinkedHashSet.class;
-			} else if (SortedSet.class.equals(targetClass)) {
-				return TreeSet.class;
-			} else {
-				throw new IllegalArgumentException("Unsupported collection interface [" + targetClass.getName() + "]");
-			}
-		} else {
-			return targetClass;
-		}
-	}
-
 	private ConversionExecutor getElementConverter(Object source, Class targetClass) {
 		if (elementConverter != null) {
 			return elementConverter;

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

@@ -35,7 +35,7 @@ import org.springframework.core.convert.converter.StringToLong;
 import org.springframework.core.convert.converter.StringToShort;
 
 /**
- * Default, local implementation of a conversion service. Will automatically register <i>from string</i> converters for
+ * Default implementation of a conversion service. Will automatically register <i>from string</i> converters for
  * a number of standard Java types like Class, Number, Boolean and so on.
  * 
  * @author Keith Donald
@@ -67,6 +67,7 @@ public class DefaultConversionService extends GenericConversionService {
 		addConverter(new StringToLocale());
 		addConverter(new StringToEnum());
 		addConverter(new NumberToNumber());
+		// TODO probably don't allow these to be customized, or at least make public
 		addConverter(new ObjectToCollection(this));
 		addConverter(new CollectionToCollection(this));
 	}

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

@@ -34,11 +34,14 @@ import org.springframework.core.convert.ConversionExecutorNotFoundException;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.convert.converter.SuperConverter;
+import org.springframework.core.convert.converter.SuperTwoWayConverter;
 import org.springframework.util.Assert;
 
 /**
  * Base implementation of a conversion service. Initially empty, e.g. no converters are registered by default.
  * 
+ * TODO custom converters TODO handle case where no Converter/SuperConverter generic param info is available
+ * 
  * @author Keith Donald
  */
 @SuppressWarnings("unchecked")
@@ -50,6 +53,12 @@ public class GenericConversionService implements ConversionService {
 	 */
 	private final Map sourceClassConverters = new HashMap();
 
+	/**
+	 * An indexed map of Converters. Each Map.Entry key is a source class (S) that can be converted from. Each Map.Entry
+	 * value is a Map that defines the targetClass-to-Converter mappings for that source.
+	 */
+	private final Map sourceClassSuperConverters = new HashMap();
+
 	/**
 	 * Indexes classes by well-known aliases.
 	 */
@@ -95,7 +104,17 @@ public class GenericConversionService implements ConversionService {
 	 * @param converter the super converter to register
 	 */
 	public void addConverter(SuperConverter converter) {
-		// TODO
+		List typeInfo = getTypeInfo(converter);
+		Class sourceClass = (Class) typeInfo.get(0);
+		Class targetClass = (Class) typeInfo.get(1);
+		// index forward
+		Map sourceMap = getSourceSuperConverterMap(sourceClass);
+		sourceMap.put(targetClass, converter);
+		if (converter instanceof SuperTwoWayConverter) {
+			// index reverse
+			sourceMap = getSourceSuperConverterMap(targetClass);
+			sourceMap.put(sourceClass, new ReverseSuperConverter((SuperTwoWayConverter) converter));
+		}
 	}
 
 	/**
@@ -109,22 +128,14 @@ public class GenericConversionService implements ConversionService {
 
 	public Object executeConversion(Object source, Class targetClass) throws ConversionExecutorNotFoundException,
 			ConversionException {
-		if (source != null) {
+		ConversionExecutor conversionExecutor = getConversionExecutor(source.getClass(), targetClass);
-			ConversionExecutor conversionExecutor = getConversionExecutor(source.getClass(), targetClass);
+		return conversionExecutor.execute(source);
-			return conversionExecutor.execute(source);
-		} else {
-			return null;
-		}
 	}
 
 	public Object executeConversion(String converterId, Object source, Class targetClass)
 			throws ConversionExecutorNotFoundException, ConversionException {
-		if (source != null) {
+		ConversionExecutor conversionExecutor = getConversionExecutor(converterId, source.getClass(), targetClass);
-			ConversionExecutor conversionExecutor = getConversionExecutor(converterId, source.getClass(), targetClass);
+		return conversionExecutor.execute(source);
-			return conversionExecutor.execute(source);
-		} else {
-			return null;
-		}
 	}
 
 	public ConversionExecutor getConversionExecutor(Class sourceClass, Class targetClass)
@@ -151,7 +162,8 @@ public class GenericConversionService implements ConversionService {
 		}
 		if (targetClass.isArray()) {
 			if (Collection.class.isAssignableFrom(sourceClass)) {
-				return new StaticSuperConversionExecutor(sourceClass, targetClass, new CollectionToArray(this));
+				SuperConverter collectionToArray = new ReverseSuperConverter(new ArrayToCollection(this));
+				return new StaticSuperConversionExecutor(sourceClass, targetClass, collectionToArray);
 			} else {
 				return new StaticSuperConversionExecutor(sourceClass, targetClass, new ObjectToArray(this));
 			}
@@ -161,6 +173,10 @@ public class GenericConversionService implements ConversionService {
 			// we found a converter
 			return new StaticConversionExecutor(sourceClass, targetClass, converter);
 		} else {
+			SuperConverter superConverter = findRegisteredSuperConverter(sourceClass, targetClass);
+			if (superConverter != null) {
+				return new StaticSuperConversionExecutor(sourceClass, targetClass, superConverter);
+			}
 			if (parent != null) {
 				// try the parent
 				return parent.getConversionExecutor(sourceClass, targetClass);
@@ -192,7 +208,7 @@ public class GenericConversionService implements ConversionService {
 
 	// internal helpers
 
-	private List getTypeInfo(Converter converter) {
+	private List getTypeInfo(Object converter) {
 		List typeInfo = new ArrayList(2);
 		Class classToIntrospect = converter.getClass();
 		while (classToIntrospect != null) {
@@ -200,7 +216,8 @@ public class GenericConversionService implements ConversionService {
 			for (Type genericInterface : genericInterfaces) {
 				if (genericInterface instanceof ParameterizedType) {
 					ParameterizedType parameterizedInterface = (ParameterizedType) genericInterface;
-					if (Converter.class.equals(parameterizedInterface.getRawType())) {
+					if (Converter.class.equals(parameterizedInterface.getRawType())
+							|| SuperConverter.class.isAssignableFrom((Class) parameterizedInterface.getRawType())) {
 						Type s = parameterizedInterface.getActualTypeArguments()[0];
 						Type t = parameterizedInterface.getActualTypeArguments()[1];
 						typeInfo.add(getParameterClass(s, converter.getClass()));
@@ -213,12 +230,12 @@ public class GenericConversionService implements ConversionService {
 		return typeInfo;
 	}
 
-	private Class<?> getParameterClass(Type parameterType, Class<?> converterClass) {
+	private Class getParameterClass(Type parameterType, Class converterClass) {
 		if (parameterType instanceof TypeVariable) {
-			parameterType = GenericTypeResolver.resolveTypeVariable((TypeVariable<?>) parameterType, converterClass);
+			parameterType = GenericTypeResolver.resolveTypeVariable((TypeVariable) parameterType, converterClass);
 		}
 		if (parameterType instanceof Class) {
-			return (Class<?>) parameterType;
+			return (Class) parameterType;
 		}
 		// when would this happen?
 		return null;
@@ -227,12 +244,21 @@ public class GenericConversionService implements ConversionService {
 	private Map getSourceMap(Class sourceClass) {
 		Map sourceMap = (Map) sourceClassConverters.get(sourceClass);
 		if (sourceMap == null) {
-			sourceMap = new HashMap<Class<?>, Converter<?, ?>>();
+			sourceMap = new HashMap();
 			sourceClassConverters.put(sourceClass, sourceMap);
 		}
 		return sourceMap;
 	}
 
+	private Map getSourceSuperConverterMap(Class sourceClass) {
+		Map sourceMap = (Map) sourceClassSuperConverters.get(sourceClass);
+		if (sourceMap == null) {
+			sourceMap = new HashMap();
+			sourceClassSuperConverters.put(sourceClass, sourceMap);
+		}
+		return sourceMap;
+	}
+
 	private Class convertToWrapperClassIfNecessary(Class targetType) {
 		if (targetType.isPrimitive()) {
 			if (targetType.equals(int.class)) {
@@ -265,8 +291,8 @@ public class GenericConversionService implements ConversionService {
 			classQueue.addFirst(sourceClass);
 			while (!classQueue.isEmpty()) {
 				Class currentClass = (Class) classQueue.removeLast();
-				Map<Class, Converter> sourceTargetConverters = findConvertersForSource(currentClass);
+				Map converters = getConvertersForSource(currentClass);
-				Converter converter = findTargetConverter(sourceTargetConverters, targetClass);
+				Converter converter = getConverter(converters, targetClass);
 				if (converter != null) {
 					return converter;
 				}
@@ -275,15 +301,15 @@ public class GenericConversionService implements ConversionService {
 					classQueue.addFirst(interfaces[i]);
 				}
 			}
-			Map objectConverters = findConvertersForSource(Object.class);
+			Map objectConverters = getConvertersForSource(Object.class);
-			return findTargetConverter(objectConverters, targetClass);
+			return getConverter(objectConverters, targetClass);
 		} else {
 			LinkedList classQueue = new LinkedList();
 			classQueue.addFirst(sourceClass);
 			while (!classQueue.isEmpty()) {
 				Class currentClass = (Class) classQueue.removeLast();
-				Map sourceTargetConverters = findConvertersForSource(currentClass);
+				Map converters = getConvertersForSource(currentClass);
-				Converter converter = findTargetConverter(sourceTargetConverters, targetClass);
+				Converter converter = getConverter(converters, targetClass);
 				if (converter != null) {
 					return converter;
 				}
@@ -299,15 +325,98 @@ public class GenericConversionService implements ConversionService {
 		}
 	}
 
-	private Map findConvertersForSource(Class sourceClass) {
+	private Map getConvertersForSource(Class sourceClass) {
-		Map sourceConverters = (Map) sourceClassConverters.get(sourceClass);
+		Map converters = (Map) sourceClassConverters.get(sourceClass);
-		return sourceConverters != null ? sourceConverters : Collections.emptyMap();
+		return converters != null ? converters : Collections.emptyMap();
 	}
 
-	private Converter findTargetConverter(Map sourceTargetConverters, Class targetClass) {
+	private Converter getConverter(Map converters, Class targetClass) {
-		if (sourceTargetConverters.isEmpty()) {
+		return (Converter) converters.get(targetClass);
+	}
+
+	private SuperConverter findRegisteredSuperConverter(Class sourceClass, Class targetClass) {
+		if (sourceClass.isInterface()) {
+			LinkedList classQueue = new LinkedList();
+			classQueue.addFirst(sourceClass);
+			while (!classQueue.isEmpty()) {
+				Class currentClass = (Class) classQueue.removeLast();
+				Map converters = getSuperConvertersForSource(currentClass);
+				SuperConverter converter = findSuperConverter(converters, targetClass);
+				if (converter != null) {
+					return converter;
+				}
+				Class[] interfaces = currentClass.getInterfaces();
+				for (int i = 0; i < interfaces.length; i++) {
+					classQueue.addFirst(interfaces[i]);
+				}
+			}
+			Map objectConverters = getSuperConvertersForSource(Object.class);
+			return findSuperConverter(objectConverters, targetClass);
+		} else {
+			LinkedList classQueue = new LinkedList();
+			classQueue.addFirst(sourceClass);
+			while (!classQueue.isEmpty()) {
+				Class currentClass = (Class) classQueue.removeLast();
+				Map converters = getSuperConvertersForSource(currentClass);
+				SuperConverter converter = findSuperConverter(converters, targetClass);
+				if (converter != null) {
+					return converter;
+				}
+				if (currentClass.getSuperclass() != null) {
+					classQueue.addFirst(currentClass.getSuperclass());
+				}
+				Class[] interfaces = currentClass.getInterfaces();
+				for (int i = 0; i < interfaces.length; i++) {
+					classQueue.addFirst(interfaces[i]);
+				}
+			}
 			return null;
 		}
-		return (Converter) sourceTargetConverters.get(targetClass);
 	}
+
+	private Map getSuperConvertersForSource(Class sourceClass) {
+		Map converters = (Map) sourceClassSuperConverters.get(sourceClass);
+		return converters != null ? converters : Collections.emptyMap();
+	}
+
+	private SuperConverter findSuperConverter(Map converters, Class targetClass) {
+		if (converters.isEmpty()) {
+			return null;
+		}
+		if (targetClass.isInterface()) {
+			LinkedList classQueue = new LinkedList();
+			classQueue.addFirst(targetClass);
+			while (!classQueue.isEmpty()) {
+				Class currentClass = (Class) classQueue.removeLast();
+				SuperConverter converter = (SuperConverter) converters.get(currentClass);
+				if (converter != null) {
+					return converter;
+				}
+				Class[] interfaces = currentClass.getInterfaces();
+				for (int i = 0; i < interfaces.length; i++) {
+					classQueue.addFirst(interfaces[i]);
+				}
+			}
+			return (SuperConverter) converters.get(Object.class);
+		} else {
+			LinkedList classQueue = new LinkedList();
+			classQueue.addFirst(targetClass);
+			while (!classQueue.isEmpty()) {
+				Class currentClass = (Class) classQueue.removeLast();
+				SuperConverter converter = (SuperConverter) converters.get(currentClass);
+				if (converter != null) {
+					return converter;
+				}
+				if (currentClass.getSuperclass() != null) {
+					classQueue.addFirst(currentClass.getSuperclass());
+				}
+				Class[] interfaces = currentClass.getInterfaces();
+				for (int i = 0; i < interfaces.length; i++) {
+					classQueue.addFirst(interfaces[i]);
+				}
+			}
+			return null;
+		}
+	}
+
 }

org.springframework.core/src/main/java/org/springframework/core/convert/service/NoOpConverter.java

@@ -17,11 +17,6 @@ package org.springframework.core.convert.service;
 
 import org.springframework.core.convert.converter.Converter;
 
-/**
- * Package private converter that is a "no op".
- * 
- * @author Keith Donald
- */
 @SuppressWarnings("unchecked")
 class NoOpConverter implements Converter {
 

org.springframework.core/src/main/java/org/springframework/core/convert/service/ObjectToArray.java

@@ -22,7 +22,7 @@ import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.converter.SuperConverter;
 
 /**
- * Special two-way converter that converts an object to an single-element array. Mainly used internally by
+ * Special converter that converts an object to an single-element array. Mainly used internally by
  * {@link ConversionService} implementations.
  * 
  * @author Keith Donald
@@ -51,14 +51,6 @@ class ObjectToArray implements SuperConverter {
 		this.elementConverter = elementConverter;
 	}
 
-	public Class getSourceClass() {
-		return Object.class;
-	}
-
-	public Class getSuperTargetClass() {
-		return Object[].class;
-	}
-
 	public Object convert(Object source, Class targetClass) throws Exception {
 		Class componentType = targetClass.getComponentType();
 		Object array = Array.newInstance(componentType, 1);
@@ -72,8 +64,4 @@ class ObjectToArray implements SuperConverter {
 		return array;
 	}
 
-	public Object convertBack(Object target) throws Exception {
-		throw new UnsupportedOperationException("Not supported");
-	}
-
 }

org.springframework.core/src/main/java/org/springframework/core/convert/service/ObjectToCollection.java

@@ -16,13 +16,7 @@
 package org.springframework.core.convert.service;
 
 import java.lang.reflect.Constructor;
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Set;
-import java.util.SortedSet;
-import java.util.TreeSet;
 
 import org.springframework.core.GenericCollectionTypeResolver;
 import org.springframework.core.convert.ConversionExecutor;
@@ -36,7 +30,7 @@ import org.springframework.core.convert.converter.SuperConverter;
  * @author Keith Donald
  */
 @SuppressWarnings("unchecked")
-class ObjectToCollection implements SuperConverter {
+class ObjectToCollection implements SuperConverter<Object, Collection> {
 
 	private ConversionService conversionService;
 
@@ -59,20 +53,9 @@ class ObjectToCollection implements SuperConverter {
 		this.elementConverter = elementConverter;
 	}
 
-	public Class getSourceClass() {
+	public Collection convert(Object source, Class targetClass) throws Exception {
-		return Object.class;
+		Class implClass = CollectionConversionUtils.getImpl(targetClass);
-	}
+		Constructor constructor = implClass.getConstructor((Class[]) null);
-
-	public Class getSuperTargetClass() {
-		return Collection.class;
-	}
-
-	public Object convert(Object source, Class targetClass) throws Exception {
-		if (source == null) {
-			return null;
-		}
-		Class collectionImplClass = getCollectionImplClass(targetClass);
-		Constructor constructor = collectionImplClass.getConstructor((Class[]) null);
 		Collection collection = (Collection) constructor.newInstance((Object[]) null);
 		ConversionExecutor converter = getElementConverter(source, targetClass);
 		Object value;
@@ -85,27 +68,6 @@ class ObjectToCollection implements SuperConverter {
 		return collection;
 	}
 
-	public Object convertBack(Object target) throws Exception {
-		throw new UnsupportedOperationException("Not supported");
-	}
-
-	// this code is duplicated in ArrayToCollection and CollectionToCollection
-	private Class getCollectionImplClass(Class targetClass) {
-		if (targetClass.isInterface()) {
-			if (List.class.equals(targetClass)) {
-				return ArrayList.class;
-			} else if (Set.class.equals(targetClass)) {
-				return LinkedHashSet.class;
-			} else if (SortedSet.class.equals(targetClass)) {
-				return TreeSet.class;
-			} else {
-				throw new IllegalArgumentException("Unsupported collection interface [" + targetClass.getName() + "]");
-			}
-		} else {
-			return targetClass;
-		}
-	}
-
 	private ConversionExecutor getElementConverter(Object source, Class targetClass) {
 		if (elementConverter != null) {
 			return elementConverter;

org.springframework.core/src/main/java/org/springframework/core/convert/service/ReverseSuperConverter.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2004-2009 the original author or authors.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.core.convert.service;
+
+import org.springframework.core.convert.converter.SuperConverter;
+import org.springframework.core.convert.converter.SuperTwoWayConverter;
+
+@SuppressWarnings("unchecked")
+class ReverseSuperConverter implements SuperConverter {
+
+	private SuperTwoWayConverter converter;
+
+	public ReverseSuperConverter(SuperTwoWayConverter converter) {
+		this.converter = converter;
+	}
+
+	public Object convert(Object source, Class targetClass) throws Exception {
+		return converter.convertBack(source, targetClass);
+	}
+
+}

org.springframework.core/src/main/java/org/springframework/core/convert/service/StaticConversionExecutor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2008 the original author or authors.
+ * Copyright 2004-2009 the original author or authors.
  * 
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,16 +21,15 @@ import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.style.ToStringCreator;
 import org.springframework.util.Assert;
 
-@SuppressWarnings("unchecked")
+class StaticConversionExecutor<S, T> implements ConversionExecutor<S, T> {
-class StaticConversionExecutor implements ConversionExecutor {
 
-	private final Class sourceClass;
+	private final Class<S> sourceClass;
 
-	private final Class targetClass;
+	private final Class<T> targetClass;
 
-	private final Converter converter;
+	private final Converter<S, T> converter;
 
-	public StaticConversionExecutor(Class sourceClass, Class targetClass, Converter converter) {
+	public StaticConversionExecutor(Class<S> sourceClass, Class<T> targetClass, Converter<S, T> converter) {
 		Assert.notNull(sourceClass, "The source class is required");
 		Assert.notNull(targetClass, "The target class is required");
 		Assert.notNull(converter, "The converter is required");
@@ -39,15 +38,15 @@ class StaticConversionExecutor implements ConversionExecutor {
 		this.converter = converter;
 	}
 
-	public Class getSourceClass() {
+	public Class<S> getSourceClass() {
 		return sourceClass;
 	}
 
-	public Class getTargetClass() {
+	public Class<T> getTargetClass() {
 		return targetClass;
 	}
 
-	public Object execute(Object source) throws ConversionExecutionException {
+	public T execute(S source) throws ConversionExecutionException {
 		if (source == null) {
 			return null;
 		}
@@ -66,7 +65,7 @@ class StaticConversionExecutor implements ConversionExecutor {
 		if (!(o instanceof StaticConversionExecutor)) {
 			return false;
 		}
-		StaticConversionExecutor other = (StaticConversionExecutor) o;
+		StaticConversionExecutor<?, ?> other = (StaticConversionExecutor<?, ?>) o;
 		return sourceClass.equals(other.sourceClass) && targetClass.equals(other.targetClass);
 	}
 

org.springframework.core/src/main/java/org/springframework/core/convert/service/StaticSuperConversionExecutor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2008 the original author or authors.
+ * Copyright 2004-2009 the original author or authors.
  * 
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,16 +21,15 @@ import org.springframework.core.convert.converter.SuperConverter;
 import org.springframework.core.style.ToStringCreator;
 import org.springframework.util.Assert;
 
-@SuppressWarnings("unchecked")
+class StaticSuperConversionExecutor<S, T> implements ConversionExecutor<S, T> {
-class StaticSuperConversionExecutor implements ConversionExecutor {
 
-	private final Class sourceClass;
+	private final Class<S> sourceClass;
 
-	private final Class targetClass;
+	private final Class<T> targetClass;
 
-	private final SuperConverter converter;
+	private final SuperConverter<S, T> converter;
 
-	public StaticSuperConversionExecutor(Class sourceClass, Class targetClass, SuperConverter converter) {
+	public StaticSuperConversionExecutor(Class<S> sourceClass, Class<T> targetClass, SuperConverter<S, T> converter) {
 		Assert.notNull(sourceClass, "The source class is required");
 		Assert.notNull(targetClass, "The target class is required");
 		Assert.notNull(converter, "The super converter is required");
@@ -39,15 +38,15 @@ class StaticSuperConversionExecutor implements ConversionExecutor {
 		this.converter = converter;
 	}
 
-	public Class getSourceClass() {
+	public Class<S> getSourceClass() {
 		return sourceClass;
 	}
-	
+
-	public Class getTargetClass() {
+	public Class<T> getTargetClass() {
 		return targetClass;
 	}
 
-	public Object execute(Object source) throws ConversionExecutionException {
+	public T execute(S source) throws ConversionExecutionException {
 		if (source == null) {
 			return null;
 		}
@@ -66,7 +65,7 @@ class StaticSuperConversionExecutor implements ConversionExecutor {
 		if (!(o instanceof StaticSuperConversionExecutor)) {
 			return false;
 		}
-		StaticSuperConversionExecutor other = (StaticSuperConversionExecutor) o;
+		StaticSuperConversionExecutor<?, ?> other = (StaticSuperConversionExecutor<?, ?>) o;
 		return sourceClass.equals(other.sourceClass) && targetClass.equals(other.targetClass);
 	}
 

org.springframework.core/src/test/java/org/springframework/core/convert/service/DefaultConversionServiceTests.java

@@ -1,159 +0,0 @@
-/*
- * Copyright 2004-2009 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.core.convert.service;
-
-import java.util.AbstractList;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.LinkedList;
-import java.util.List;
-
-import junit.framework.TestCase;
-
-import org.springframework.core.convert.ConversionExecutor;
-import org.springframework.core.convert.ConversionExecutorNotFoundException;
-import org.springframework.core.convert.ConversionService;
-import org.springframework.core.convert.converter.Converter;
-import org.springframework.core.convert.converter.StringToBoolean;
-
-/**
- * Test case for the default conversion service.
- * 
- * @author Keith Donald
- */
-public class DefaultConversionServiceTests extends TestCase {
-
-	ConversionService service = new DefaultConversionService();
-
-	public void testConversionForwardIndex() {
-		ConversionExecutor<String, Integer> executor = service.getConversionExecutor(String.class, Integer.class);
-		Integer three = executor.execute("3");
-		assertEquals(3, three.intValue());
-	}
-
-	public void testConversionReverseIndex() {
-		ConversionExecutor<Integer, String> executor = service.getConversionExecutor(Integer.class, String.class);
-		String threeString = executor.execute(new Integer(3));
-		assertEquals("3", threeString);
-	}
-
-	public void testConversionCompatibleTypes() {
-		ArrayList source = new ArrayList();
-		assertSame(source, service.getConversionExecutor(ArrayList.class, List.class).execute(source));
-	}
-
-	public void testConversionOverrideDefaultConverter() {
-		Converter<String, Boolean> customConverter = new StringToBoolean("ja", "nee");
-		((GenericConversionService) service).addConverter(customConverter);
-		ConversionExecutor<String, Boolean> executor = service.getConversionExecutor(String.class, Boolean.class);
-		assertTrue(executor.execute("ja").booleanValue());
-	}
-
-	public void testConverterLookupTargetClassNotSupported() {
-		try {
-			service.getConversionExecutor(String.class, HashMap.class);
-			fail("Should have thrown an exception");
-		} catch (ConversionExecutorNotFoundException e) {
-		}
-	}
-
-	public void testConversionToPrimitive() {
-		DefaultConversionService service = new DefaultConversionService();
-		ConversionExecutor executor = service.getConversionExecutor(String.class, int.class);
-		Integer three = (Integer) executor.execute("3");
-		assertEquals(3, three.intValue());
-	}
-
-	public void testConversionArrayToArray() {
-		ConversionExecutor executor = service.getConversionExecutor(String[].class, Integer[].class);
-		Integer[] result = (Integer[]) executor.execute(new String[] { "1", "2", "3" });
-		assertEquals(new Integer(1), result[0]);
-		assertEquals(new Integer(2), result[1]);
-		assertEquals(new Integer(3), result[2]);
-	}
-
-	public void testConversionArrayToPrimitiveArray() {
-		ConversionExecutor executor = service.getConversionExecutor(String[].class, int[].class);
-		int[] result = (int[]) executor.execute(new String[] { "1", "2", "3" });
-		assertEquals(1, result[0]);
-		assertEquals(2, result[1]);
-		assertEquals(3, result[2]);
-	}
-
-	public void testConversionArrayToList() {
-		ConversionExecutor executor = service.getConversionExecutor(String[].class, List.class);
-		List result = (List) executor.execute(new String[] { "1", "2", "3" });
-		assertEquals("1", result.get(0));
-		assertEquals("2", result.get(1));
-		assertEquals("3", result.get(2));
-	}
-
-	public void testConversionToArray() {
-		ConversionExecutor executor = service.getConversionExecutor(Collection.class, String[].class);
-		List list = new ArrayList();
-		list.add("1");
-		list.add("2");
-		list.add("3");
-		String[] result = (String[]) executor.execute(list);
-		assertEquals("1", result[0]);
-		assertEquals("2", result[1]);
-		assertEquals("3", result[2]);
-	}
-
-	public void testConversionListToArrayWithComponentConversion() {
-		ConversionExecutor executor = service.getConversionExecutor(Collection.class, Integer[].class);
-		List list = new ArrayList();
-		list.add("1");
-		list.add("2");
-		list.add("3");
-		Integer[] result = (Integer[]) executor.execute(list);
-		assertEquals(new Integer(1), result[0]);
-		assertEquals(new Integer(2), result[1]);
-		assertEquals(new Integer(3), result[2]);
-	}
-
-	public void testConversionArrayToConcreteList() {
-		ConversionExecutor executor = service.getConversionExecutor(String[].class, LinkedList.class);
-		LinkedList result = (LinkedList) executor.execute(new String[] { "1", "2", "3" });
-		assertEquals("1", result.get(0));
-		assertEquals("2", result.get(1));
-		assertEquals("3", result.get(2));
-	}
-
-	public void testConversionArrayToAbstractList() {
-		try {
-			service.getConversionExecutor(String[].class, AbstractList.class);
-		} catch (IllegalArgumentException e) {
-
-		}
-	}
-
-	public void testConversionStringToArray() {
-		ConversionExecutor executor = service.getConversionExecutor(String.class, String[].class);
-		String[] result = (String[]) executor.execute("1,2,3");
-		assertEquals(1, result.length);
-		assertEquals("1,2,3", result[0]);
-	}
-
-	public void testConversionStringToArrayWithElementConversion() {
-		ConversionExecutor executor = service.getConversionExecutor(String.class, Integer[].class);
-		Integer[] result = (Integer[]) executor.execute("123");
-		assertEquals(1, result.length);
-		assertEquals(new Integer(123), result[0]);
-	}
-
-}

org.springframework.core/src/test/java/org/springframework/core/convert/service/GenericConversionServiceTests.java

@@ -0,0 +1,253 @@
+package org.springframework.core.convert.service;
+
+import java.util.AbstractList;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+
+import junit.framework.TestCase;
+
+import org.springframework.core.convert.ConversionExecutionException;
+import org.springframework.core.convert.ConversionExecutor;
+import org.springframework.core.convert.ConversionExecutorNotFoundException;
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.core.convert.converter.NumberToNumber;
+import org.springframework.core.convert.converter.StringToEnum;
+import org.springframework.core.convert.converter.StringToInteger;
+import org.springframework.core.convert.service.GenericConversionService;
+
+public class GenericConversionServiceTests extends TestCase {
+
+	private GenericConversionService service = new GenericConversionService();
+
+	public void testExecuteConversion() {
+		service.addConverter(new StringToInteger());
+		assertEquals(new Integer(3), service.executeConversion("3", Integer.class));
+	}
+
+	public void testConverterConversionForwardIndex() {
+		service.addConverter(new StringToInteger());
+		ConversionExecutor executor = service.getConversionExecutor(String.class, Integer.class);
+		Integer three = (Integer) executor.execute("3");
+		assertEquals(3, three.intValue());
+	}
+
+	public void testConverterConversionReverseIndex() {
+		service.addConverter(new StringToInteger());
+		ConversionExecutor executor = service.getConversionExecutor(Integer.class, String.class);
+		String threeString = (String) executor.execute(new Integer(3));
+		assertEquals("3", threeString);
+	}
+
+	public void testConversionExecutorNotFound() {
+		try {
+			service.getConversionExecutor(String.class, Integer.class);
+			fail("Should have thrown an exception");
+		} catch (ConversionExecutorNotFoundException e) {
+		}
+	}
+
+	public void testConversionCompatibleTypes() {
+		ArrayList source = new ArrayList();
+		assertSame(source, service.getConversionExecutor(ArrayList.class, List.class).execute(source));
+	}
+
+	public void testConversionExecutorNullArgument() {
+		service.addConverter(new StringToInteger());
+		ConversionExecutor executor = service.getConversionExecutor(String.class, Integer.class);
+		assertNull(executor.execute(null));
+	}
+
+	public void testConversionExecutorWrongTypeArgument() {
+		service.addConverter(new StringToInteger());
+		ConversionExecutor executor = service.getConversionExecutor(Integer.class, String.class);
+		try {
+			executor.execute("BOGUS");
+			fail("Should have failed");
+		} catch (ConversionExecutionException e) {
+
+		}
+	}
+
+	public void testConverterConversionSuperSourceType() {
+		service.addConverter(new Converter<CharSequence, Integer>() {
+			public Integer convert(CharSequence source) throws Exception {
+				return Integer.valueOf(source.toString());
+			}
+
+			public CharSequence convertBack(Integer target) throws Exception {
+				return target.toString();
+			}
+		});
+		ConversionExecutor executor = service.getConversionExecutor(String.class, Integer.class);
+		Integer result = (Integer) executor.execute("3");
+		assertEquals(new Integer(3), result);
+	}
+
+	public void testConverterConversionNoSuperTargetType() {
+		service.addConverter(new Converter<CharSequence, Number>() {
+			public Integer convert(CharSequence source) throws Exception {
+				return Integer.valueOf(source.toString());
+			}
+
+			public CharSequence convertBack(Number target) throws Exception {
+				return target.toString();
+			}
+		});
+		try {
+			ConversionExecutor executor = service.getConversionExecutor(String.class, Integer.class);
+			fail("Should have failed");
+		} catch (ConversionExecutorNotFoundException e) {
+
+		}
+	}
+
+	public void testConversionObjectToPrimitive() {
+		service.addConverter(new StringToInteger());
+		ConversionExecutor executor = service.getConversionExecutor(String.class, int.class);
+		Integer three = (Integer) executor.execute("3");
+		assertEquals(3, three.intValue());
+	}
+
+	public void testConversionArrayToArray() {
+		service.addConverter(new StringToInteger());
+		ConversionExecutor executor = service.getConversionExecutor(String[].class, Integer[].class);
+		Integer[] result = (Integer[]) executor.execute(new String[] { "1", "2", "3" });
+		assertEquals(new Integer(1), result[0]);
+		assertEquals(new Integer(2), result[1]);
+		assertEquals(new Integer(3), result[2]);
+	}
+
+	public void testConversionArrayToPrimitiveArray() {
+		service.addConverter(new StringToInteger());
+		ConversionExecutor executor = service.getConversionExecutor(String[].class, int[].class);
+		int[] result = (int[]) executor.execute(new String[] { "1", "2", "3" });
+		assertEquals(1, result[0]);
+		assertEquals(2, result[1]);
+		assertEquals(3, result[2]);
+	}
+
+	public void testConversionArrayToListInterface() {
+		ConversionExecutor executor = service.getConversionExecutor(String[].class, List.class);
+		List result = (List) executor.execute(new String[] { "1", "2", "3" });
+		assertEquals("1", result.get(0));
+		assertEquals("2", result.get(1));
+		assertEquals("3", result.get(2));
+	}
+
+	public void testConversionArrayToListImpl() {
+		ConversionExecutor executor = service.getConversionExecutor(String[].class, LinkedList.class);
+		LinkedList result = (LinkedList) executor.execute(new String[] { "1", "2", "3" });
+		assertEquals("1", result.get(0));
+		assertEquals("2", result.get(1));
+		assertEquals("3", result.get(2));
+	}
+
+	public void testConversionArrayToAbstractList() {
+		try {
+			service.getConversionExecutor(String[].class, AbstractList.class);
+		} catch (IllegalArgumentException e) {
+
+		}
+	}
+
+	public void testConversionListToArray() {
+		ConversionExecutor executor = service.getConversionExecutor(Collection.class, String[].class);
+		List list = new ArrayList();
+		list.add("1");
+		list.add("2");
+		list.add("3");
+		String[] result = (String[]) executor.execute(list);
+		assertEquals("1", result[0]);
+		assertEquals("2", result[1]);
+		assertEquals("3", result[2]);
+	}
+
+	public void testConversionListToArrayWithComponentConversion() {
+		service.addConverter(new StringToInteger());
+		ConversionExecutor executor = service.getConversionExecutor(Collection.class, Integer[].class);
+		List list = new ArrayList();
+		list.add("1");
+		list.add("2");
+		list.add("3");
+		Integer[] result = (Integer[]) executor.execute(list);
+		assertEquals(new Integer(1), result[0]);
+		assertEquals(new Integer(2), result[1]);
+		assertEquals(new Integer(3), result[2]);
+	}
+
+	public void testConversionObjectToArray() {
+		ConversionExecutor executor = service.getConversionExecutor(String.class, String[].class);
+		String[] result = (String[]) executor.execute("1,2,3");
+		assertEquals(1, result.length);
+		assertEquals("1,2,3", result[0]);
+	}
+
+	public void testConversionObjectToArrayWithElementConversion() {
+		service.addConverter(new StringToInteger());
+		ConversionExecutor executor = service.getConversionExecutor(String.class, Integer[].class);
+		Integer[] result = (Integer[]) executor.execute("123");
+		assertEquals(1, result.length);
+		assertEquals(new Integer(123), result[0]);
+	}
+
+	public static enum FooEnum {
+		BAR
+	}
+
+	public void testSuperConverterConversionForwardIndex() {
+		service.addConverter(new StringToEnum());
+		ConversionExecutor executor = service.getConversionExecutor(String.class, FooEnum.class);
+		assertEquals(FooEnum.BAR, executor.execute("BAR"));
+	}
+
+	public void testSuperTwoWayConverterConversionReverseIndex() {
+		service.addConverter(new StringToEnum());
+		ConversionExecutor executor = service.getConversionExecutor(FooEnum.class, String.class);
+		assertEquals("BAR", executor.execute(FooEnum.BAR));
+	}
+
+	public void testSuperConverterConversionNotConvertibleAbstractType() {
+		service.addConverter(new StringToEnum());
+		ConversionExecutor executor = service.getConversionExecutor(String.class, Enum.class);
+		try {
+			executor.execute("WHATEV");
+			fail("Should have failed");
+		} catch (ConversionExecutionException e) {
+
+		}
+	}
+
+	public void testSuperConverterConversionNotConvertibleAbstractType2() {
+		service.addConverter(new NumberToNumber());
+		Number customNumber = new Number() {
+			@Override
+			public double doubleValue() {
+				return 0;
+			}
+
+			@Override
+			public float floatValue() {
+				return 0;
+			}
+
+			@Override
+			public int intValue() {
+				return 0;
+			}
+
+			@Override
+			public long longValue() {
+				return 0;
+			}
+		};
+		ConversionExecutor executor = service.getConversionExecutor(Integer.class, customNumber.getClass());
+		try {
+			executor.execute(3);
+			fail("Should have failed");
+		} catch (ConversionExecutionException e) {
+
+		}
+	}
+}