bundles/org.eclipse.core.databinding.beans/src/org/eclipse/core/databinding/beans/PojoProperties.java - e4/org.eclipse.e4.databinding - Git at Google

 /*******************************************************************************
  * Copyright (c) 2008, 2009 Matthew Hall and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     Matthew Hall - initial API and implementation (bug 194734)
  *     Matthew Hall - bug 195222, 247997, 261843, 264307
  ******************************************************************************/

 package org.eclipse.core.databinding.beans;

 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyDescriptor;
 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.core.databinding.property.list.IListProperty;
 import org.eclipse.core.databinding.property.map.IMapProperty;
 import org.eclipse.core.databinding.property.set.ISetProperty;
 import org.eclipse.core.databinding.property.value.IValueProperty;
 import org.eclipse.core.internal.databinding.beans.AnonymousPojoListProperty;
 import org.eclipse.core.internal.databinding.beans.AnonymousPojoMapProperty;
 import org.eclipse.core.internal.databinding.beans.AnonymousPojoSetProperty;
 import org.eclipse.core.internal.databinding.beans.AnonymousPojoValueProperty;
 import org.eclipse.core.internal.databinding.beans.BeanPropertyHelper;
 import org.eclipse.core.internal.databinding.beans.PojoListProperty;
 import org.eclipse.core.internal.databinding.beans.PojoListPropertyDecorator;
 import org.eclipse.core.internal.databinding.beans.PojoMapProperty;
 import org.eclipse.core.internal.databinding.beans.PojoMapPropertyDecorator;
 import org.eclipse.core.internal.databinding.beans.PojoSetProperty;
 import org.eclipse.core.internal.databinding.beans.PojoSetPropertyDecorator;
 import org.eclipse.core.internal.databinding.beans.PojoValueProperty;
 import org.eclipse.core.internal.databinding.beans.PojoValuePropertyDecorator;

 /**
  * A factory for creating properties for POJOs (plain old java objects) that
  * conform to idea of an object with getters and setters but does not provide
  * {@link PropertyChangeEvent property change events} on change. This factory is
  * identical to {@link BeanProperties} except for this fact.
  *
  * @since 1.2
  */
 public class PojoProperties {
 	/**
 	 * Returns a value property for the given property name of an arbitrary bean
 	 * class. Objects lacking the named property are treated the same as if the
 	 * property always contains null.
 	 *
 	 * @param propertyName
 	 *            the property name. May be nested e.g. "parent.name"
 	 * @return a value property for the given property name of an arbitrary bean
 	 *         class.
 	 */
 	public static IBeanValueProperty<Object, Object> value(String propertyName) {
 		String[] propertyNames = splitOffFirst(propertyName);

 		if (propertyNames.length == 1) {
 			return new PojoValuePropertyDecorator<Object, Object>(
 					new AnonymousPojoValueProperty<Object, Object>(
 							propertyNames[0], null), null);
 		}

 		IValueProperty<Object, Object> x = new AnonymousPojoValueProperty<Object, Object>(
 				propertyNames[0], Object.class);

 		IBeanValueProperty<Object, Object> remainder = value(propertyNames[1]);

 		IValueProperty<Object, Object> y = x.value(remainder);

 		return new PojoValuePropertyDecorator<Object, Object>(y, null);
 	}

 	/**
 	 * Returns a value property for the given property name of an arbitrary bean
 	 * class. Objects lacking the named property are treated the same as if the
 	 * property always contains null.
 	 *
 	 * @param propertyName
 	 *            the property name. May be nested e.g. "parent.name"
 	 * @param valueType
 	 *            the value type of the returned value property
 	 * @return a value property for the given property name of an arbitrary bean
 	 *         class.
 	 */
 	public static <T> IBeanValueProperty<Object, T> value(String propertyName,
 			Class<T> valueType) {
 		String[] propertyNames = splitOffFirst(propertyName);

 		if (propertyNames.length == 1) {
 			return new PojoValuePropertyDecorator<Object, T>(
 					new AnonymousPojoValueProperty<Object, T>(propertyNames[0],
 							valueType), null);
 		}

 		IValueProperty<Object, Object> x = new AnonymousPojoValueProperty<Object, Object>(
 				propertyNames[0], Object.class);

 		IBeanValueProperty<Object, T> remainder = value(propertyNames[1],
 				valueType);

 		IValueProperty<Object, T> y = x.value(remainder);

 		return new PojoValuePropertyDecorator<Object, T>(y, null);
 	}

 	/**
 	 * Returns a value property for the given property name of the given bean
 	 * class.
 	 * <P>
 	 * The property must be available in the class given by the
 	 * <code>beanClass</code> parameter. For example suppose Foo is a class and
 	 * Bar extends Foo. There are methods getMyProperty and setMyProperty in Bar
 	 * but not in Foo. value(Foo.class, "myProperty") is called to get an
 	 * IValueProperty instance. The IValueProperty is then used to get the
 	 * property value from an object of type Bar. Null will always be returned.
 	 *
 	 * @param beanClass
 	 *            the bean class
 	 * @param propertyName
 	 *            the property name. May be nested e.g. "parent.name"
 	 * @return a value property for the given property name of the given bean
 	 *         class.
 	 */
 	public static <S> IBeanValueProperty<S, ?> value(Class<S> beanClass,
 			String propertyName) {
 		String[] propertyNames = splitOffFirst(propertyName);

 		if (beanClass == null) {
 			// beanClass cannot be null.
 			throw new IllegalArgumentException();
 		}

 		PropertyDescriptor propertyDescriptor = BeanPropertyHelper
 				.getPropertyDescriptor(beanClass, propertyNames[0]);

 		if (propertyNames.length == 1) {
 			/*
 			 * If a non-null valueType is provided by the caller then it must
 			 * match the actual property type. If no valueType is provided by
 			 * the caller then set it to the actual type from the property
 			 * descriptor.
 			 */
 			Class<?> valueType = propertyDescriptor.getPropertyType();

 			return valueUsingActualType(propertyDescriptor, valueType);
 		}

 		return valueGivenDescriptor(beanClass, propertyDescriptor,
 				propertyDescriptor.getPropertyType(), propertyNames[1]);
 	}

 	private static <S, T> IBeanValueProperty<S, T> valueUsingActualType(
 			PropertyDescriptor propertyDescriptor, Class<T> valueType) {
 		IValueProperty<S, T> property = new PojoValueProperty<S, T>(
 				propertyDescriptor, valueType);
 		return new PojoValuePropertyDecorator<S, T>(property,
 				propertyDescriptor);
 	}

 	/**
 	 * Returns a value property for the given property name of the given bean
 	 * class.
 	 *
 	 * @param beanClass
 	 *            the bean class
 	 * @param propertyName
 	 *            the property name. May be nested e.g. "parent.name"
 	 * @param valueType
 	 *            the value type of the returned value property
 	 * @return a value property for the given property name of the given bean
 	 *         class.
 	 */
 	public static <S, T> IBeanValueProperty<S, T> value(
 			Class<? extends S> beanClass, String propertyName,
 			Class<T> valueType) {
 		String[] propertyNames = splitOffFirst(propertyName);

 		if (beanClass == null) {
 			// beanClass cannot be null.
 			throw new IllegalArgumentException();
 		}
 		if (valueType == null) {
 			// valueType cannot be null.
 			throw new IllegalArgumentException();
 		}

 		PropertyDescriptor propertyDescriptor = BeanPropertyHelper
 				.getPropertyDescriptor(beanClass, propertyNames[0]);

 		if (propertyNames.length == 1) {
 			IValueProperty<S, T> property = new PojoValueProperty<S, T>(
 					propertyDescriptor, valueType);
 			return new PojoValuePropertyDecorator<S, T>(property,
 					propertyDescriptor);
 		}

 		return valueGivenDescriptor(beanClass, propertyDescriptor,
 				propertyDescriptor.getPropertyType(), propertyNames[1],
 				valueType);
 	}

 	/**
 	 * This is a private method used by the above to recursively chain
 	 * IValueProperty objects when the bean property name has multiple parts
 	 * ("parent.child").
 	 * <P>
 	 * This method is given the property descriptor for the getter method that
 	 * gets one from the parent (class S) to the first level child (class I). It
 	 * then makes a recursive call to get the IValueProperty that gets from the
 	 * first level child to the final property (class T).
 	 *
 	 * @param <S>
 	 *            type of the parent object, being the object that contains the
 	 *            property specified by propertyDescriptor
 	 * @param <I>
 	 *            type of the intermediate object, being the first level child
 	 *            object and being the property type of the property specified
 	 *            by propertyDescriptor
 	 * @param sourceBeanClass
 	 * @param propertyDescriptor
 	 * @param childBeanClass
 	 * @param propertyName
 	 *            the property name. May be nested e.g. "parent.name"
 	 * @return a value property that gets from S to T
 	 */
 	private static <S, I> IBeanValueProperty<S, ?> valueGivenDescriptor(
 			Class<? extends S> sourceBeanClass,
 			PropertyDescriptor propertyDescriptor, Class<I> childBeanClass,
 			String propertyName) {

 		IValueProperty<S, I> property = new PojoValueProperty<S, I>(
 				propertyDescriptor, childBeanClass);
 		IBeanValueProperty<S, I> decoratedProperty = new PojoValuePropertyDecorator<S, I>(
 				property, propertyDescriptor);

 		IBeanValueProperty<I, ?> remainder = value(childBeanClass, propertyName);

 		return decoratedProperty.value(remainder);
 	}

 	/**
 	 * This is a private method used by the above to recursively chain
 	 * IValueProperty objects when the bean property name has multiple parts
 	 * ("parent.child").
 	 * <P>
 	 * This method is given the property descriptor for the getter method that
 	 * gets one from the parent (class S) to the first level child (class I). It
 	 * then makes a recursive call to get the IValueProperty that gets from the
 	 * first level child to the final property (class T).
 	 *
 	 * @param <S>
 	 *            type of the parent object, being the object that contains the
 	 *            property specified by propertyDescriptor
 	 * @param <I>
 	 *            type of the intermediate object, being the first level child
 	 *            object and being the property type of the property specified
 	 *            by propertyDescriptor
 	 * @param <T>
 	 *            expected type of the final child given
 	 * @param sourceBeanClass
 	 * @param propertyDescriptor
 	 * @param childBeanClass
 	 * @param propertyName
 	 *            the property name. May be nested e.g. "parent.name"
 	 * @param valueType
 	 *            the expected type of the final child property which may be
 	 *            null if the caller does not know the type in advance
 	 * @return a value property that gets from S to T
 	 */
 	private static <S, I, T> IBeanValueProperty<S, T> valueGivenDescriptor(
 			Class<? extends S> sourceBeanClass,
 			PropertyDescriptor propertyDescriptor, Class<I> childBeanClass,
 			String propertyName, Class<T> valueType) {

 		IValueProperty<S, I> property = new PojoValueProperty<S, I>(
 				propertyDescriptor, childBeanClass);
 		IBeanValueProperty<S, I> decoratedProperty = new PojoValuePropertyDecorator<S, I>(
 				property, propertyDescriptor);

 		IBeanValueProperty<I, T> remainder = value(childBeanClass,
 				propertyName, valueType);

 		return decoratedProperty.value(remainder);
 	}

 	/**
 	 * Splits off the first part of a property name. For example, if
 	 * "parent.child.child2" is passed in then { "parent", "child.child2" } is
 	 * returned.
 	 *
 	 * @param propertyName
 	 *            the property name. May be nested e.g. "parent.name"
 	 * @return a String array with either one element if there is no 'dot' in
 	 *         the property name, or two elements split at the position of the
 	 *         first 'dot'
 	 */
 	private static String[] splitOffFirst(String propertyName) {
 		int index = propertyName.indexOf('.');
 		if (index == -1) {
 			return new String[] { propertyName };
 		}
 		return new String[] { propertyName.substring(0, index),
 				propertyName.substring(index + 1) };
 	}

 	/**
 	 * Returns a value property array for the given property names of the given
 	 * bean class.
 	 *
 	 * @param beanClass
 	 *            the bean class
 	 * @param propertyNames
 	 *            array of property names. May be nested e.g. "parent.name"
 	 * @return a value property array for the given property names of the given
 	 *         bean class.
 	 * @deprecated use instead valuesAsList because that returns better typing
 	 */
 	public static <S> IBeanValueProperty<?, ?>[] values(Class<S> beanClass,
 			String[] propertyNames) {
 		IBeanValueProperty<?, ?>[] properties = new IBeanValueProperty[propertyNames.length];
 		for (int i = 0; i < properties.length; i++)
 			properties[i] = value(beanClass, propertyNames[i], null);
 		return properties;
 	}

 	/**
 	 * Returns a value property array for the given property names of the given
 	 * bean class.
 	 *
 	 * @param beanClass
 	 *            the bean class
 	 * @param propertyNames
 	 *            array of property names. May be nested e.g. "parent.name"
 	 * @return a value property array for the given property names of the given
 	 *         bean class.
 	 * @since 1.5
 	 */
 	public static <S> List<IBeanValueProperty<S, Object>> valuesAsList(
 			Class<S> beanClass, String[] propertyNames) {
 		List<IBeanValueProperty<S, Object>> properties = new ArrayList<IBeanValueProperty<S, Object>>(
 				propertyNames.length);
 		for (int i = 0; i < propertyNames.length; i++)
 			properties.add(value(beanClass, propertyNames[i], null));
 		return properties;
 	}

 	/**
 	 * Returns a value property array for the given property names of an
 	 * arbitrary bean class.
 	 *
 	 * @param propertyNames
 	 *            array of property names. May be nested e.g. "parent.name"
 	 * @return a value property array for the given property names of the given
 	 *         bean class.
 	 * @deprecated use instead valuesAsList because that returns better typing
 	 */
 	public static IBeanValueProperty<?, ?>[] values(String[] propertyNames) {
 		return values(null, propertyNames);
 	}

 	/**
 	 * Returns a value property array for the given property names of an
 	 * arbitrary bean class.
 	 *
 	 * @param propertyNames
 	 *            array of property names. May be nested e.g. "parent.name"
 	 * @return a value property array for the given property names of the given
 	 *         bean class.
 	 * @since 1.5
 	 */
 	public static <S> List<IBeanValueProperty<S, Object>> valuesAsList(
 			String[] propertyNames) {
 		return valuesAsList(null, propertyNames);
 	}

 	/**
 	 * Returns a set property for the given property name of an arbitrary bean
 	 * class. Objects lacking the named property are treated the same as if the
 	 * property always contains an empty set.
 	 *
 	 * @param propertyName
 	 *            the property name
 	 * @return a set property for the given property name of an arbitrary bean
 	 *         class.
 	 */
 	public static IBeanSetProperty<Object, Object> set(String propertyName) {
 		return set(null, propertyName, null);
 	}

 	/**
 	 * Returns a set property for the given property name of an arbitrary bean
 	 * class. Objects lacking the named property are treated the same as if the
 	 * property always contains an empty set.
 	 *
 	 * @param propertyName
 	 *            the property name
 	 * @param elementType
 	 *            the element type of the returned set property
 	 * @return a set property for the given property name of an arbitrary bean
 	 *         class.
 	 */
 	public static <S, E> IBeanSetProperty<S, E> set(String propertyName,
 			Class<E> elementType) {
 		return set(null, propertyName, elementType);
 	}

 	/**
 	 * Returns a set property for the given property name of the given bean
 	 * class.
 	 *
 	 * @param beanClass
 	 *            the bean class
 	 * @param propertyName
 	 *            the property name
 	 * @return a set property for the given property name of the given bean
 	 *         class.
 	 */
 	public static <S, E> IBeanSetProperty<S, E> set(Class<S> beanClass,
 			String propertyName) {
 		return set(beanClass, propertyName, null);
 	}

 	/**
 	 * Returns a set property for the given property name of the given bean
 	 * class.
 	 *
 	 * @param beanClass
 	 *            the bean class
 	 * @param propertyName
 	 *            the property name
 	 * @param elementType
 	 *            the element type of the returned set property
 	 * @return a set property for the given property name of the given bean
 	 *         class.
 	 */
 	public static <S, E> IBeanSetProperty<S, E> set(
 			Class<? extends S> beanClass, String propertyName,
 			Class<E> elementType) {
 		PropertyDescriptor propertyDescriptor;
 		ISetProperty<S, E> property;
 		if (beanClass == null) {
 			propertyDescriptor = null;
 			property = new AnonymousPojoSetProperty<S, E>(propertyName,
 					elementType);
 		} else {
 			propertyDescriptor = BeanPropertyHelper.getPropertyDescriptor(
 					beanClass, propertyName);
 			property = new PojoSetProperty<S, E>(propertyDescriptor,
 					elementType);
 		}
 		return new PojoSetPropertyDecorator<S, E>(property, propertyDescriptor);
 	}

 	/**
 	 * Returns a list property for the given property name of an arbitrary bean
 	 * class. Objects lacking the named property are treated the same as if the
 	 * property always contains an empty list.
 	 *
 	 * @param propertyName
 	 *            the property name
 	 * @return a list property for the given property name of an arbitrary bean
 	 *         class.
 	 */
 	public static <E> IBeanListProperty<Object, E> list(String propertyName) {
 		return list(null, propertyName, null);
 	}

 	/**
 	 * Returns a list property for the given property name of an arbitrary bean
 	 * class. Objects lacking the named property are treated the same as if the
 	 * property always contains an empty list.
 	 *
 	 * @param propertyName
 	 *            the property name
 	 * @param elementType
 	 *            the element type of the returned list property
 	 * @return a list property for the given property name of the given bean
 	 *         class.
 	 */
 	public static <E> IBeanListProperty<Object, E> list(String propertyName,
 			Class<E> elementType) {
 		return list(null, propertyName, elementType);
 	}

 	/**
 	 * Returns a list property for the given property name of the given bean
 	 * class.
 	 *
 	 * @param beanClass
 	 *            the bean class
 	 * @param propertyName
 	 *            the property name
 	 * @return a list property for the given property name of the given bean
 	 *         class.
 	 */
 	public static <S, E> IBeanListProperty<S, E> list(Class<S> beanClass,
 			String propertyName) {
 		return list(beanClass, propertyName, null);
 	}

 	/**
 	 * Returns a list property for the given property name of the given bean
 	 * class.
 	 *
 	 * @param beanClass
 	 *            the bean class
 	 * @param propertyName
 	 *            the property name
 	 * @param elementType
 	 *            the element type of the returned list property
 	 * @return a list property for the given property name of the given bean
 	 *         class.
 	 */
 	public static <S, E> IBeanListProperty<S, E> list(
 			Class<? extends S> beanClass, String propertyName,
 			Class<E> elementType) {
 		PropertyDescriptor propertyDescriptor;
 		IListProperty<S, E> property;
 		if (beanClass == null) {
 			propertyDescriptor = null;
 			property = new AnonymousPojoListProperty<S, E>(propertyName,
 					elementType);
 		} else {
 			propertyDescriptor = BeanPropertyHelper.getPropertyDescriptor(
 					beanClass, propertyName);
 			property = new PojoListProperty<S, E>(propertyDescriptor,
 					elementType);
 		}
 		return new PojoListPropertyDecorator<S, E>(property, propertyDescriptor);
 	}

 	/**
 	 * Returns a map property for the given property name of an arbitrary bean
 	 * class. Objects lacking the named property are treated the same as if the
 	 * property always contains an empty map.
 	 *
 	 * @param propertyName
 	 *            the property name
 	 * @return a map property for the given property name of an arbitrary bean
 	 *         class.
 	 */
 	public static <S> IBeanMapProperty<S, Object, Object> map(
 			String propertyName) {
 		return map(null, propertyName, null, null);
 	}

 	/**
 	 * Returns a map property for the given property name of an arbitrary bean
 	 * class. Objects lacking the named property are treated the same as if the
 	 * property always contains an empty map.
 	 *
 	 * @param propertyName
 	 *            the property name
 	 * @param keyType
 	 *            the key type for the returned map property
 	 * @param valueType
 	 *            the value type for the returned map property
 	 * @return a map property for the given property name of an arbitrary bean
 	 *         class.
 	 */
 	public static <S, K, V> IBeanMapProperty<S, K, V> map(String propertyName,
 			Class<K> keyType, Class<V> valueType) {
 		return map(null, propertyName, keyType, valueType);
 	}

 	/**
 	 * Returns a map property for the given property name of the given bean
 	 * class.
 	 *
 	 * @param beanClass
 	 *            the bean class
 	 * @param propertyName
 	 *            the property name
 	 * @return a map property for the given property name of the given bean
 	 *         class.
 	 */
 	public static <S, K, V> IBeanMapProperty<S, K, V> map(Class<S> beanClass,
 			String propertyName) {
 		return map(beanClass, propertyName, null, null);
 	}

 	/**
 	 * Returns a map property for the given property name of the given bean
 	 * class.
 	 *
 	 * @param beanClass
 	 *            the bean class
 	 * @param propertyName
 	 *            the property name
 	 * @param keyType
 	 *            the key type of the returned map property
 	 * @param valueType
 	 *            the value type of the returned map property
 	 * @return a map property for the given property name of the given bean
 	 *         class.
 	 */
 	public static <S, K, V> IBeanMapProperty<S, K, V> map(
 			Class<? extends S> beanClass, String propertyName,
 			Class<K> keyType, Class<V> valueType) {
 		PropertyDescriptor propertyDescriptor;
 		IMapProperty<S, K, V> property;
 		if (beanClass == null) {
 			propertyDescriptor = null;
 			property = new AnonymousPojoMapProperty<S, K, V>(propertyName,
 					keyType, valueType);
 		} else {
 			propertyDescriptor = BeanPropertyHelper.getPropertyDescriptor(
 					beanClass, propertyName);
 			property = new PojoMapProperty<S, K, V>(propertyDescriptor,
 					keyType, valueType);
 		}
 		return new PojoMapPropertyDecorator<S, K, V>(property,
 				propertyDescriptor);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2008, 2009 Matthew Hall and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* Matthew Hall - initial API and implementation (bug 194734)
	* Matthew Hall - bug 195222, 247997, 261843, 264307
	******************************************************************************/

	package org.eclipse.core.databinding.beans;

	import java.beans.PropertyChangeEvent;
	import java.beans.PropertyDescriptor;
	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.core.databinding.property.list.IListProperty;
	import org.eclipse.core.databinding.property.map.IMapProperty;
	import org.eclipse.core.databinding.property.set.ISetProperty;
	import org.eclipse.core.databinding.property.value.IValueProperty;
	import org.eclipse.core.internal.databinding.beans.AnonymousPojoListProperty;
	import org.eclipse.core.internal.databinding.beans.AnonymousPojoMapProperty;
	import org.eclipse.core.internal.databinding.beans.AnonymousPojoSetProperty;
	import org.eclipse.core.internal.databinding.beans.AnonymousPojoValueProperty;
	import org.eclipse.core.internal.databinding.beans.BeanPropertyHelper;
	import org.eclipse.core.internal.databinding.beans.PojoListProperty;
	import org.eclipse.core.internal.databinding.beans.PojoListPropertyDecorator;
	import org.eclipse.core.internal.databinding.beans.PojoMapProperty;
	import org.eclipse.core.internal.databinding.beans.PojoMapPropertyDecorator;
	import org.eclipse.core.internal.databinding.beans.PojoSetProperty;
	import org.eclipse.core.internal.databinding.beans.PojoSetPropertyDecorator;
	import org.eclipse.core.internal.databinding.beans.PojoValueProperty;
	import org.eclipse.core.internal.databinding.beans.PojoValuePropertyDecorator;

	/**
	* A factory for creating properties for POJOs (plain old java objects) that
	* conform to idea of an object with getters and setters but does not provide
	* {@link PropertyChangeEvent property change events} on change. This factory is
	* identical to {@link BeanProperties} except for this fact.
	*
	* @since 1.2
	*/
	public class PojoProperties {
	/**
	* Returns a value property for the given property name of an arbitrary bean
	* class. Objects lacking the named property are treated the same as if the
	* property always contains null.
	*
	* @param propertyName
	* the property name. May be nested e.g. "parent.name"
	* @return a value property for the given property name of an arbitrary bean
	* class.
	*/
	public static IBeanValueProperty<Object, Object> value(String propertyName) {
	String[] propertyNames = splitOffFirst(propertyName);

	if (propertyNames.length == 1) {
	return new PojoValuePropertyDecorator<Object, Object>(
	new AnonymousPojoValueProperty<Object, Object>(
	propertyNames[0], null), null);
	}

	IValueProperty<Object, Object> x = new AnonymousPojoValueProperty<Object, Object>(
	propertyNames[0], Object.class);

	IBeanValueProperty<Object, Object> remainder = value(propertyNames[1]);

	IValueProperty<Object, Object> y = x.value(remainder);

	return new PojoValuePropertyDecorator<Object, Object>(y, null);
	}

	/**
	* Returns a value property for the given property name of an arbitrary bean
	* class. Objects lacking the named property are treated the same as if the
	* property always contains null.
	*
	* @param propertyName
	* the property name. May be nested e.g. "parent.name"
	* @param valueType
	* the value type of the returned value property
	* @return a value property for the given property name of an arbitrary bean
	* class.
	*/
	public static <T> IBeanValueProperty<Object, T> value(String propertyName,
	Class<T> valueType) {
	String[] propertyNames = splitOffFirst(propertyName);

	if (propertyNames.length == 1) {
	return new PojoValuePropertyDecorator<Object, T>(
	new AnonymousPojoValueProperty<Object, T>(propertyNames[0],
	valueType), null);
	}

	IValueProperty<Object, Object> x = new AnonymousPojoValueProperty<Object, Object>(
	propertyNames[0], Object.class);

	IBeanValueProperty<Object, T> remainder = value(propertyNames[1],
	valueType);

	IValueProperty<Object, T> y = x.value(remainder);

	return new PojoValuePropertyDecorator<Object, T>(y, null);
	}

	/**
	* Returns a value property for the given property name of the given bean
	* class.
	* <P>
	* The property must be available in the class given by the
	* <code>beanClass</code> parameter. For example suppose Foo is a class and
	* Bar extends Foo. There are methods getMyProperty and setMyProperty in Bar
	* but not in Foo. value(Foo.class, "myProperty") is called to get an
	* IValueProperty instance. The IValueProperty is then used to get the
	* property value from an object of type Bar. Null will always be returned.
	*
	* @param beanClass
	* the bean class
	* @param propertyName
	* the property name. May be nested e.g. "parent.name"
	* @return a value property for the given property name of the given bean
	* class.
	*/
	public static <S> IBeanValueProperty<S, ?> value(Class<S> beanClass,
	String propertyName) {
	String[] propertyNames = splitOffFirst(propertyName);

	if (beanClass == null) {
	// beanClass cannot be null.
	throw new IllegalArgumentException();
	}

	PropertyDescriptor propertyDescriptor = BeanPropertyHelper
	.getPropertyDescriptor(beanClass, propertyNames[0]);

	if (propertyNames.length == 1) {
	/*
	* If a non-null valueType is provided by the caller then it must
	* match the actual property type. If no valueType is provided by
	* the caller then set it to the actual type from the property
	* descriptor.
	*/
	Class<?> valueType = propertyDescriptor.getPropertyType();

	return valueUsingActualType(propertyDescriptor, valueType);
	}

	return valueGivenDescriptor(beanClass, propertyDescriptor,
	propertyDescriptor.getPropertyType(), propertyNames[1]);
	}

	private static <S, T> IBeanValueProperty<S, T> valueUsingActualType(
	PropertyDescriptor propertyDescriptor, Class<T> valueType) {
	IValueProperty<S, T> property = new PojoValueProperty<S, T>(
	propertyDescriptor, valueType);
	return new PojoValuePropertyDecorator<S, T>(property,
	propertyDescriptor);
	}

	/**
	* Returns a value property for the given property name of the given bean
	* class.
	*
	* @param beanClass
	* the bean class
	* @param propertyName
	* the property name. May be nested e.g. "parent.name"
	* @param valueType
	* the value type of the returned value property
	* @return a value property for the given property name of the given bean
	* class.
	*/
	public static <S, T> IBeanValueProperty<S, T> value(
	Class<? extends S> beanClass, String propertyName,
	Class<T> valueType) {
	String[] propertyNames = splitOffFirst(propertyName);

	if (beanClass == null) {
	// beanClass cannot be null.
	throw new IllegalArgumentException();
	}
	if (valueType == null) {
	// valueType cannot be null.
	throw new IllegalArgumentException();
	}

	PropertyDescriptor propertyDescriptor = BeanPropertyHelper
	.getPropertyDescriptor(beanClass, propertyNames[0]);

	if (propertyNames.length == 1) {
	IValueProperty<S, T> property = new PojoValueProperty<S, T>(
	propertyDescriptor, valueType);
	return new PojoValuePropertyDecorator<S, T>(property,
	propertyDescriptor);
	}

	return valueGivenDescriptor(beanClass, propertyDescriptor,
	propertyDescriptor.getPropertyType(), propertyNames[1],
	valueType);
	}

	/**
	* This is a private method used by the above to recursively chain
	* IValueProperty objects when the bean property name has multiple parts
	* ("parent.child").
	* <P>
	* This method is given the property descriptor for the getter method that
	* gets one from the parent (class S) to the first level child (class I). It
	* then makes a recursive call to get the IValueProperty that gets from the
	* first level child to the final property (class T).
	*
	* @param <S>
	* type of the parent object, being the object that contains the
	* property specified by propertyDescriptor
	* @param <I>
	* type of the intermediate object, being the first level child
	* object and being the property type of the property specified
	* by propertyDescriptor
	* @param sourceBeanClass
	* @param propertyDescriptor
	* @param childBeanClass
	* @param propertyName
	* the property name. May be nested e.g. "parent.name"
	* @return a value property that gets from S to T
	*/
	private static <S, I> IBeanValueProperty<S, ?> valueGivenDescriptor(
	Class<? extends S> sourceBeanClass,
	PropertyDescriptor propertyDescriptor, Class<I> childBeanClass,
	String propertyName) {

	IValueProperty<S, I> property = new PojoValueProperty<S, I>(
	propertyDescriptor, childBeanClass);
	IBeanValueProperty<S, I> decoratedProperty = new PojoValuePropertyDecorator<S, I>(
	property, propertyDescriptor);

	IBeanValueProperty<I, ?> remainder = value(childBeanClass, propertyName);

	return decoratedProperty.value(remainder);
	}

	/**
	* This is a private method used by the above to recursively chain
	* IValueProperty objects when the bean property name has multiple parts
	* ("parent.child").
	* <P>
	* This method is given the property descriptor for the getter method that
	* gets one from the parent (class S) to the first level child (class I). It
	* then makes a recursive call to get the IValueProperty that gets from the
	* first level child to the final property (class T).
	*
	* @param <S>
	* type of the parent object, being the object that contains the
	* property specified by propertyDescriptor
	* @param <I>
	* type of the intermediate object, being the first level child
	* object and being the property type of the property specified
	* by propertyDescriptor
	* @param <T>
	* expected type of the final child given
	* @param sourceBeanClass
	* @param propertyDescriptor
	* @param childBeanClass
	* @param propertyName
	* the property name. May be nested e.g. "parent.name"
	* @param valueType
	* the expected type of the final child property which may be
	* null if the caller does not know the type in advance
	* @return a value property that gets from S to T
	*/
	private static <S, I, T> IBeanValueProperty<S, T> valueGivenDescriptor(
	Class<? extends S> sourceBeanClass,
	PropertyDescriptor propertyDescriptor, Class<I> childBeanClass,
	String propertyName, Class<T> valueType) {

	IValueProperty<S, I> property = new PojoValueProperty<S, I>(
	propertyDescriptor, childBeanClass);
	IBeanValueProperty<S, I> decoratedProperty = new PojoValuePropertyDecorator<S, I>(
	property, propertyDescriptor);

	IBeanValueProperty<I, T> remainder = value(childBeanClass,
	propertyName, valueType);

	return decoratedProperty.value(remainder);
	}

	/**
	* Splits off the first part of a property name. For example, if
	* "parent.child.child2" is passed in then { "parent", "child.child2" } is
	* returned.
	*
	* @param propertyName
	* the property name. May be nested e.g. "parent.name"
	* @return a String array with either one element if there is no 'dot' in
	* the property name, or two elements split at the position of the
	* first 'dot'
	*/
	private static String[] splitOffFirst(String propertyName) {
	int index = propertyName.indexOf('.');
	if (index == -1) {
	return new String[] { propertyName };
	}
	return new String[] { propertyName.substring(0, index),
	propertyName.substring(index + 1) };
	}

	/**
	* Returns a value property array for the given property names of the given
	* bean class.
	*
	* @param beanClass
	* the bean class
	* @param propertyNames
	* array of property names. May be nested e.g. "parent.name"
	* @return a value property array for the given property names of the given
	* bean class.
	* @deprecated use instead valuesAsList because that returns better typing
	*/
	public static <S> IBeanValueProperty<?, ?>[] values(Class<S> beanClass,
	String[] propertyNames) {
	IBeanValueProperty<?, ?>[] properties = new IBeanValueProperty[propertyNames.length];
	for (int i = 0; i < properties.length; i++)
	properties[i] = value(beanClass, propertyNames[i], null);
	return properties;
	}

	/**
	* Returns a value property array for the given property names of the given
	* bean class.
	*
	* @param beanClass
	* the bean class
	* @param propertyNames
	* array of property names. May be nested e.g. "parent.name"
	* @return a value property array for the given property names of the given
	* bean class.
	* @since 1.5
	*/
	public static <S> List<IBeanValueProperty<S, Object>> valuesAsList(
	Class<S> beanClass, String[] propertyNames) {
	List<IBeanValueProperty<S, Object>> properties = new ArrayList<IBeanValueProperty<S, Object>>(
	propertyNames.length);
	for (int i = 0; i < propertyNames.length; i++)
	properties.add(value(beanClass, propertyNames[i], null));
	return properties;
	}

	/**
	* Returns a value property array for the given property names of an
	* arbitrary bean class.
	*
	* @param propertyNames
	* array of property names. May be nested e.g. "parent.name"
	* @return a value property array for the given property names of the given
	* bean class.
	* @deprecated use instead valuesAsList because that returns better typing
	*/
	public static IBeanValueProperty<?, ?>[] values(String[] propertyNames) {
	return values(null, propertyNames);
	}

	/**
	* Returns a value property array for the given property names of an
	* arbitrary bean class.
	*
	* @param propertyNames
	* array of property names. May be nested e.g. "parent.name"
	* @return a value property array for the given property names of the given
	* bean class.
	* @since 1.5
	*/
	public static <S> List<IBeanValueProperty<S, Object>> valuesAsList(
	String[] propertyNames) {
	return valuesAsList(null, propertyNames);
	}

	/**
	* Returns a set property for the given property name of an arbitrary bean
	* class. Objects lacking the named property are treated the same as if the
	* property always contains an empty set.
	*
	* @param propertyName
	* the property name
	* @return a set property for the given property name of an arbitrary bean
	* class.
	*/
	public static IBeanSetProperty<Object, Object> set(String propertyName) {
	return set(null, propertyName, null);
	}

	/**
	* Returns a set property for the given property name of an arbitrary bean
	* class. Objects lacking the named property are treated the same as if the
	* property always contains an empty set.
	*
	* @param propertyName
	* the property name
	* @param elementType
	* the element type of the returned set property
	* @return a set property for the given property name of an arbitrary bean
	* class.
	*/
	public static <S, E> IBeanSetProperty<S, E> set(String propertyName,
	Class<E> elementType) {
	return set(null, propertyName, elementType);
	}

	/**
	* Returns a set property for the given property name of the given bean
	* class.
	*
	* @param beanClass
	* the bean class
	* @param propertyName
	* the property name
	* @return a set property for the given property name of the given bean
	* class.
	*/
	public static <S, E> IBeanSetProperty<S, E> set(Class<S> beanClass,
	String propertyName) {
	return set(beanClass, propertyName, null);
	}

	/**
	* Returns a set property for the given property name of the given bean
	* class.
	*
	* @param beanClass
	* the bean class
	* @param propertyName
	* the property name
	* @param elementType
	* the element type of the returned set property
	* @return a set property for the given property name of the given bean
	* class.
	*/
	public static <S, E> IBeanSetProperty<S, E> set(
	Class<? extends S> beanClass, String propertyName,
	Class<E> elementType) {
	PropertyDescriptor propertyDescriptor;
	ISetProperty<S, E> property;
	if (beanClass == null) {
	propertyDescriptor = null;
	property = new AnonymousPojoSetProperty<S, E>(propertyName,
	elementType);
	} else {
	propertyDescriptor = BeanPropertyHelper.getPropertyDescriptor(
	beanClass, propertyName);
	property = new PojoSetProperty<S, E>(propertyDescriptor,
	elementType);
	}
	return new PojoSetPropertyDecorator<S, E>(property, propertyDescriptor);
	}

	/**
	* Returns a list property for the given property name of an arbitrary bean
	* class. Objects lacking the named property are treated the same as if the
	* property always contains an empty list.
	*
	* @param propertyName
	* the property name
	* @return a list property for the given property name of an arbitrary bean
	* class.
	*/
	public static <E> IBeanListProperty<Object, E> list(String propertyName) {
	return list(null, propertyName, null);
	}

	/**
	* Returns a list property for the given property name of an arbitrary bean
	* class. Objects lacking the named property are treated the same as if the
	* property always contains an empty list.
	*
	* @param propertyName
	* the property name
	* @param elementType
	* the element type of the returned list property
	* @return a list property for the given property name of the given bean
	* class.
	*/
	public static <E> IBeanListProperty<Object, E> list(String propertyName,
	Class<E> elementType) {
	return list(null, propertyName, elementType);
	}

	/**
	* Returns a list property for the given property name of the given bean
	* class.
	*
	* @param beanClass
	* the bean class
	* @param propertyName
	* the property name
	* @return a list property for the given property name of the given bean
	* class.
	*/
	public static <S, E> IBeanListProperty<S, E> list(Class<S> beanClass,
	String propertyName) {
	return list(beanClass, propertyName, null);
	}

	/**
	* Returns a list property for the given property name of the given bean
	* class.
	*
	* @param beanClass
	* the bean class
	* @param propertyName
	* the property name
	* @param elementType
	* the element type of the returned list property
	* @return a list property for the given property name of the given bean
	* class.
	*/
	public static <S, E> IBeanListProperty<S, E> list(
	Class<? extends S> beanClass, String propertyName,
	Class<E> elementType) {
	PropertyDescriptor propertyDescriptor;
	IListProperty<S, E> property;
	if (beanClass == null) {
	propertyDescriptor = null;
	property = new AnonymousPojoListProperty<S, E>(propertyName,
	elementType);
	} else {
	propertyDescriptor = BeanPropertyHelper.getPropertyDescriptor(
	beanClass, propertyName);
	property = new PojoListProperty<S, E>(propertyDescriptor,
	elementType);
	}
	return new PojoListPropertyDecorator<S, E>(property, propertyDescriptor);
	}

	/**
	* Returns a map property for the given property name of an arbitrary bean
	* class. Objects lacking the named property are treated the same as if the
	* property always contains an empty map.
	*
	* @param propertyName
	* the property name
	* @return a map property for the given property name of an arbitrary bean
	* class.
	*/
	public static <S> IBeanMapProperty<S, Object, Object> map(
	String propertyName) {
	return map(null, propertyName, null, null);
	}

	/**
	* Returns a map property for the given property name of an arbitrary bean
	* class. Objects lacking the named property are treated the same as if the
	* property always contains an empty map.
	*
	* @param propertyName
	* the property name
	* @param keyType
	* the key type for the returned map property
	* @param valueType
	* the value type for the returned map property
	* @return a map property for the given property name of an arbitrary bean
	* class.
	*/
	public static <S, K, V> IBeanMapProperty<S, K, V> map(String propertyName,
	Class<K> keyType, Class<V> valueType) {
	return map(null, propertyName, keyType, valueType);
	}

	/**
	* Returns a map property for the given property name of the given bean
	* class.
	*
	* @param beanClass
	* the bean class
	* @param propertyName
	* the property name
	* @return a map property for the given property name of the given bean
	* class.
	*/
	public static <S, K, V> IBeanMapProperty<S, K, V> map(Class<S> beanClass,
	String propertyName) {
	return map(beanClass, propertyName, null, null);
	}

	/**
	* Returns a map property for the given property name of the given bean
	* class.
	*
	* @param beanClass
	* the bean class
	* @param propertyName
	* the property name
	* @param keyType
	* the key type of the returned map property
	* @param valueType
	* the value type of the returned map property
	* @return a map property for the given property name of the given bean
	* class.
	*/
	public static <S, K, V> IBeanMapProperty<S, K, V> map(
	Class<? extends S> beanClass, String propertyName,
	Class<K> keyType, Class<V> valueType) {
	PropertyDescriptor propertyDescriptor;
	IMapProperty<S, K, V> property;
	if (beanClass == null) {
	propertyDescriptor = null;
	property = new AnonymousPojoMapProperty<S, K, V>(propertyName,
	keyType, valueType);
	} else {
	propertyDescriptor = BeanPropertyHelper.getPropertyDescriptor(
	beanClass, propertyName);
	property = new PojoMapProperty<S, K, V>(propertyDescriptor,
	keyType, valueType);
	}
	return new PojoMapPropertyDecorator<S, K, V>(property,
	propertyDescriptor);
	}
	}