propertyresolver.java

Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容易而轻松。 Wicket利用一个POJO data beans组件使得它可以与任何持久层技术相结合。

					else
					{
						getAndSetter = new FieldGetAndSetter(field);
					}
				}
			}
			else
			{
				field = findField(clz, exp);
				getAndSetter = new MethodGetAndSet(method, MethodGetAndSet.findSetter(method, clz),
					field);
			}
			getAndSetters.put(exp, getAndSetter);
		}
		return getAndSetter;
	}


	/**
	 * @param clz
	 * @param expression
	 * @return introspected field
	 */
	private static Field findField(Class clz, String expression)
	{
		Field field = null;
		try
		{
			field = clz.getField(expression);
		}
		catch (Exception e)
		{
			Class tmp = clz;
			while (tmp != null && tmp != Object.class)
			{
				Field[] fields = tmp.getDeclaredFields();
				for (int i = 0; i < fields.length; i++)
				{
					if (fields[i].getName().equals(expression))
					{
						fields[i].setAccessible(true);
						return fields[i];
					}
				}
				tmp = tmp.getSuperclass();
			}
			log.debug("Cannot find field " + clz + "." + expression, e);
		}
		return field;
	}

	/**
	 * @param clz
	 * @param expression
	 * @return The method for the expression null if not found
	 */
	private final static Method findGetter(Class clz, String expression)
	{
		String name = Character.toUpperCase(expression.charAt(0)) + expression.substring(1);
		Method method = null;
		try
		{
			method = clz.getMethod("get" + name, null);
		}
		catch (Exception e)
		{
		}
		if (method == null)
		{
			try
			{
				method = clz.getMethod("is" + name, null);
			}
			catch (Exception e)
			{
				log.debug("Cannot find getter " + clz + "." + expression);
			}
		}
		return method;
	}

	private final static Method findMethod(Class clz, String expression)
	{
		if (expression.endsWith("()"))
		{
			expression = expression.substring(0, expression.length() - 2);
		}
		Method method = null;
		try
		{
			method = clz.getMethod(expression, null);
		}
		catch (Exception e)
		{
			log.debug("Cannot find method " + clz + "." + expression, e);
		}
		return method;
	}

	/**
	 * Utility class: instantiation not allowed.
	 */
	private PropertyResolver()
	{
	}

	/**
	 * @author jcompagner
	 * 
	 */
	private final static class ObjectAndGetSetter
	{

		private final IGetAndSet getAndSetter;
		private final Object value;

		/**
		 * @param getAndSetter
		 * @param value
		 */
		public ObjectAndGetSetter(IGetAndSet getAndSetter, Object value)
		{
			this.getAndSetter = getAndSetter;
			this.value = value;
		}

		/**
		 * @param value
		 * @param converter
		 */
		public void setValue(Object value, PropertyResolverConverter converter)
		{
			getAndSetter.setValue(this.value, value, converter);
		}

		/**
		 * @return The value
		 */
		public Object getValue()
		{
			return getAndSetter.getValue(value);
		}

		/**
		 * @return class of property value
		 */
		public Class getTargetClass()
		{
			return getAndSetter.getTargetClass();
		}

		/**
		 * @return Field or null if no field exists for expression
		 */
		public Field getField()
		{
			return getAndSetter.getField();
		}

		/**
		 * @return Getter method or null if no getter exists for expression
		 */
		public Method getGetter()
		{
			return getAndSetter.getGetter();
		}

		/**
		 * @return Setter method or null if no setter exists for expression
		 */
		public Method getSetter()
		{
			return getAndSetter.getSetter();
		}

	}


	private static interface IGetAndSet
	{
		/**
		 * @param object
		 *            The object where the value must be taken from.
		 * 
		 * @return The value of this property
		 */
		public Object getValue(final Object object);

		/**
		 * @return The target class of the object that as to be set.
		 */
		public Class getTargetClass();

		/**
		 * @param object
		 *            The object where the new value must be set on.
		 * 
		 * @return The new value for the property that is set back on that object.
		 */
		public Object newValue(Object object);

		/**
		 * @param object
		 * @param value
		 * @param converter
		 */
		public void setValue(final Object object, final Object value,
			PropertyResolverConverter converter);

		/**
		 * @return Field or null if there is no field
		 */
		public Field getField();

		/**
		 * @return Getter method or null if there is no getter
		 */
		public Method getGetter();

		/**
		 * @return Setter of null if there is no setter
		 */
		public Method getSetter();
	}

	private static abstract class AbstractGetAndSet implements IGetAndSet
	{
		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#getField()
		 */
		public Field getField()
		{
			return null;
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#getGetter()
		 */
		public Method getGetter()
		{
			return null;
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#getSetter()
		 */
		public Method getSetter()
		{
			return null;
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#getTargetClass()
		 */
		public Class getTargetClass()
		{
			return null;
		}
	}

	private static final class MapGetSet extends AbstractGetAndSet
	{
		final private String key;

		MapGetSet(String key)
		{
			this.key = key;
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#getValue(java.lang.Object)
		 */
		public Object getValue(Object object)
		{
			return ((Map)object).get(key);
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#setValue( Object, Object,
		 *      PropertyResolverConverter)
		 */
		public void setValue(Object object, Object value, PropertyResolverConverter converter)
		{
			((Map)object).put(key, value);
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#newValue(Object)
		 */
		public Object newValue(Object object)
		{
			// Map can't make a newValue or should it look what is more in the
			// map and try to make one of the class if finds?
			return null;
		}
	}

	private static final class ListGetSet extends AbstractGetAndSet
	{
		final private int index;

		ListGetSet(int index)
		{
			this.index = index;
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#getValue(java.lang.Object)
		 */
		public Object getValue(Object object)
		{
			return ((List)object).get(index);
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#setValue( Object, Object,
		 *      PropertyResolverConverter)
		 */
		public void setValue(Object object, Object value, PropertyResolverConverter converter)
		{
			List lst = (List)object;

			if (lst.size() > index)
			{
				lst.set(index, value);
			}
			else if (lst.size() == index)
			{
				lst.add(value);
			}
			else
			{
				while (lst.size() < index)
				{
					lst.add(null);
				}
				lst.add(value);
			}
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#newValue(Object)
		 */
		public Object newValue(Object object)
		{
			// List can't make a newValue or should it look what is more in the
			// list and try to make one of the class if finds?
			return null;
		}
	}

	private static final class ArrayGetSet extends AbstractGetAndSet
	{
		private final int index;
		private final Class clzComponentType;

		ArrayGetSet(Class clzComponentType, int index)
		{
			this.clzComponentType = clzComponentType;
			this.index = index;
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#getValue(java.lang.Object)
		 */
		public Object getValue(Object object)
		{
			return Array.get(object, index);
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#setValue( Object, Object,
		 *      PropertyResolverConverter)
		 */
		public void setValue(Object object, Object value, PropertyResolverConverter converter)
		{
			value = converter.convert(value, clzComponentType);
			Array.set(object, index, value);
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#newValue(java.lang.Object)
		 */
		public Object newValue(Object object)
		{
			Object value = null;
			try
			{
				value = clzComponentType.newInstance();
				Array.set(object, index, value);
			}
			catch (Exception e)
			{
				log.warn("Cannot set new value " + value + " at index " + index +
					" for array holding elements of class " + clzComponentType, e);
			}
			return value;
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#getTargetClass()
		 */
		public Class getTargetClass()
		{
			return clzComponentType;
		}
	}

	private static final class ArrayLengthGetSet extends AbstractGetAndSet
	{
		ArrayLengthGetSet()
		{
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#getValue(java.lang.Object)
		 */
		public Object getValue(Object object)
		{
			return new Integer(Array.getLength(object));
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#setValue( Object, Object,
		 *      PropertyResolverConverter)
		 */
		public void setValue(Object object, Object value, PropertyResolverConverter converter)
		{
			throw new WicketRuntimeException("Cant set the length on an array");
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#newValue(java.lang.Object)
		 */
		public Object newValue(Object object)
		{
			throw new WicketRuntimeException("Cant get a new value from a length of an array");
		}

		/**
		 * @see org.apache.wicket.util.lang.PropertyResolver.IGetAndSet#getTargetClass()
		 */
		public Class getTargetClass()