org.apache.commons.jxpath.util

Class ValueUtils


public class ValueUtils
extends java.lang.Object

Collection and property access utilities.
Version:
$Revision: 1.19 $ $Date: 2004/04/04 22:06:36 $
Author:
Dmitri Plotnikov

Method Summary

static Object
expandCollection(Object collection, int size)
Grows the collection if necessary to the specified size.
static Method
getAccessibleMethod(Method method)
Return an accessible method (that is, one that can be invoked via reflection) that implements the specified Method.
static int
getCollectionHint(Class clazz)
Returns 1 if the type is a collection, -1 if it is definitely not and 0 if it may be a collection in some cases.
static DynamicPropertyHandler
getDynamicPropertyHandler(Class clazz)
Returns a shared instance of the dynamic property handler class returned by getDynamicPropertyHandlerClass().
static int
getIndexedPropertyLength(Object object, IndexedPropertyDescriptor pd)
If there is a regular non-indexed read method for this property, uses this method to obtain the collection and then returns its length.
static int
getLength(Object collection)
Returns the length of the supplied collection.
static Object
getValue(Object object)
If the parameter is a container, opens the container and return the contents.
static Object
getValue(Object bean, PropertyDescriptor propertyDescriptor)
Returns the value of the bean's property represented by the supplied property descriptor.
static Object
getValue(Object bean, PropertyDescriptor propertyDescriptor, int index)
Returns the index'th element of the bean's property represented by the supplied property descriptor.
static Object
getValue(Object collection, int index)
Returns the index'th element of the supplied collection.
static boolean
isCollection(Object value)
Returns true if the object is an array or a Collection
static Iterator
iterate(Object collection)
Returns an iterator for the supplied collection.
static Object
remove(Object collection, int index)
Returns the index'th element from the supplied collection.
static void
setValue(Object bean, PropertyDescriptor propertyDescriptor, Object value)
Modifies the value of the bean's property represented by the supplied property descriptor.
static void
setValue(Object bean, PropertyDescriptor propertyDescriptor, int index, Object value)
Modifies the index'th element of the bean's property represented by the supplied property descriptor.
static void
setValue(Object collection, int index, Object value)
Modifies the index'th element of the supplied collection.

Method Details

expandCollection

public static Object expandCollection(Object collection,
                                      int size)
Grows the collection if necessary to the specified size. Returns the new, expanded collection.

getAccessibleMethod

public static Method getAccessibleMethod(Method method)
Return an accessible method (that is, one that can be invoked via reflection) that implements the specified Method. If no such method can be found, return null.
Parameters:
method - The method that we wish to call

getCollectionHint

public static int getCollectionHint(Class clazz)
Returns 1 if the type is a collection, -1 if it is definitely not and 0 if it may be a collection in some cases.

getDynamicPropertyHandler

public static DynamicPropertyHandler getDynamicPropertyHandler(Class clazz)
Returns a shared instance of the dynamic property handler class returned by getDynamicPropertyHandlerClass().

getIndexedPropertyLength

public static int getIndexedPropertyLength(Object object,
                                           IndexedPropertyDescriptor pd)
If there is a regular non-indexed read method for this property, uses this method to obtain the collection and then returns its length. Otherwise, attempts to guess the length of the collection by calling the indexed get method repeatedly. The method is supposed to throw an exception if the index is out of bounds.

getLength

public static int getLength(Object collection)
Returns the length of the supplied collection. If the supplied object is not a collection, returns 1. If collection is null, returns 0.

getValue

public static Object getValue(Object object)
If the parameter is a container, opens the container and return the contents. The method is recursive.

getValue

public static Object getValue(Object bean,
                              PropertyDescriptor propertyDescriptor)
Returns the value of the bean's property represented by the supplied property descriptor.

getValue

public static Object getValue(Object bean,
                              PropertyDescriptor propertyDescriptor,
                              int index)
Returns the index'th element of the bean's property represented by the supplied property descriptor.

getValue

public static Object getValue(Object collection,
                              int index)
Returns the index'th element of the supplied collection.

isCollection

public static boolean isCollection(Object value)
Returns true if the object is an array or a Collection

iterate

public static Iterator iterate(Object collection)
Returns an iterator for the supplied collection. If the argument is null, returns an empty iterator. If the argument is not a collection, returns an iterator that produces just that one object.

remove

public static Object remove(Object collection,
                            int index)
Returns the index'th element from the supplied collection.

setValue

public static void setValue(Object bean,
                            PropertyDescriptor propertyDescriptor,
                            Object value)
Modifies the value of the bean's property represented by the supplied property descriptor.

setValue

public static void setValue(Object bean,
                            PropertyDescriptor propertyDescriptor,
                            int index,
                            Object value)
Modifies the index'th element of the bean's property represented by the supplied property descriptor. Converts the value to the required type if necessary.

setValue

public static void setValue(Object collection,
                            int index,
                            Object value)
Modifies the index'th element of the supplied collection. Converts the value to the required type if necessary.