org.apache.commons.jxpath.util

Class ValueUtils

java.lang.Object

org.apache.commons.jxpath.util.ValueUtils

public class ValueUtils
extends java.lang.Object

Collection and property access utilities.

Version:

$Revision: 670728 $ $Date: 2008-06-23 15:12:44 -0500 (Mon, 23 Jun 2008) $

Field Summary

Fields

Modifier and Type	Field and Description
private static java.util.Map	dynamicPropertyHandlerMap
private static int	UNKNOWN_LENGTH_MAX_COUNT

Constructor Summary

Constructors

Constructor and Description
ValueUtils()

Method Summary

Modifier and Type	Method and Description
private static java.lang.Object	convert(java.lang.Object value, java.lang.Class type) Convert value to type.
static java.lang.Object	expandCollection(java.lang.Object collection, int size) Grows the collection if necessary to the specified size.
static java.lang.reflect.Method	getAccessibleMethod(java.lang.reflect.Method method) Return an accessible method (that is, one that can be invoked via reflection) that implements the specified Method.
private static java.lang.reflect.Method	getAccessibleMethodFromInterfaceNest(java.lang.Class clazz, java.lang.String methodName, java.lang.Class[] parameterTypes) Return an accessible method (that is, one that can be invoked via reflection) that implements the specified method, by scanning through all implemented interfaces and subinterfaces.
static int	getCollectionHint(java.lang.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(java.lang.Class clazz) Returns a shared instance of the dynamic property handler class returned by getDynamicPropertyHandlerClass().
static int	getIndexedPropertyLength(java.lang.Object object, java.beans.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(java.lang.Object collection) Returns the length of the supplied collection.
static java.lang.Object	getValue(java.lang.Object object) If the parameter is a container, opens the container and return the contents.
static java.lang.Object	getValue(java.lang.Object collection, int index) Returns the index'th element of the supplied collection.
static java.lang.Object	getValue(java.lang.Object bean, java.beans.PropertyDescriptor propertyDescriptor) Returns the value of the bean's property represented by the supplied property descriptor.
static java.lang.Object	getValue(java.lang.Object bean, java.beans.PropertyDescriptor propertyDescriptor, int index) Returns the index'th element of the bean's property represented by the supplied property descriptor.
static boolean	isCollection(java.lang.Object value) Returns true if the object is an array or a Collection.
static java.util.Iterator	iterate(java.lang.Object collection) Returns an iterator for the supplied collection.
static java.lang.Object	remove(java.lang.Object collection, int index) Remove the index'th element from the supplied collection.
static void	setValue(java.lang.Object collection, int index, java.lang.Object value) Modifies the index'th element of the supplied collection.
static void	setValue(java.lang.Object bean, java.beans.PropertyDescriptor propertyDescriptor, int index, java.lang.Object value) Modifies the index'th element of the bean's property represented by the supplied property descriptor.
static void	setValue(java.lang.Object bean, java.beans.PropertyDescriptor propertyDescriptor, java.lang.Object value) Modifies the value of the bean's property represented by the supplied property descriptor.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

dynamicPropertyHandlerMap

private static java.util.Map dynamicPropertyHandlerMap

UNKNOWN_LENGTH_MAX_COUNT

private static final int UNKNOWN_LENGTH_MAX_COUNT

See Also:

Constant Field Values

Constructor Detail

ValueUtils

public ValueUtils()

Method Detail

isCollection

public static boolean isCollection(java.lang.Object value)

Returns true if the object is an array or a Collection.

Parameters:

value - to test

Returns:

boolean

getCollectionHint

public static int getCollectionHint(java.lang.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.

Parameters:

clazz - to test

Returns:

int

getIndexedPropertyLength

public static int getIndexedPropertyLength(java.lang.Object object,
                                           java.beans.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.

Parameters:

object - collection

pd - IndexedPropertyDescriptor

Returns:

int

getLength

public static int getLength(java.lang.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.

Parameters:

collection - to check

Returns:

int

iterate

public static java.util.Iterator iterate(java.lang.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.

Parameters:

collection - to iterate

Returns:

Iterator

expandCollection

public static java.lang.Object expandCollection(java.lang.Object collection,
                                                int size)

Grows the collection if necessary to the specified size. Returns the new, expanded collection.

Parameters:

collection - to expand

size - desired size

Returns:

collection or array

remove

public static java.lang.Object remove(java.lang.Object collection,
                                      int index)

Remove the index'th element from the supplied collection.

Parameters:

collection - to edit

index - int

Returns:

the resulting collection

getValue

public static java.lang.Object getValue(java.lang.Object collection,
                                        int index)

Returns the index'th element of the supplied collection.

Parameters:

collection - to read

index - int

Returns:

collection[index]

setValue

public static void setValue(java.lang.Object collection,
                            int index,
                            java.lang.Object value)

Modifies the index'th element of the supplied collection. Converts the value to the required type if necessary.

Parameters:

collection - to edit

index - to replace

value - new value

getValue

public static java.lang.Object getValue(java.lang.Object bean,
                                        java.beans.PropertyDescriptor propertyDescriptor)

Returns the value of the bean's property represented by the supplied property descriptor.

Parameters:

bean - to read

propertyDescriptor - indicating what to read

Returns:

Object value

setValue

public static void setValue(java.lang.Object bean,
                            java.beans.PropertyDescriptor propertyDescriptor,
                            java.lang.Object value)

Modifies the value of the bean's property represented by the supplied property descriptor.

Parameters:

bean - to read

propertyDescriptor - indicating what to read

value - to set

convert

private static java.lang.Object convert(java.lang.Object value,
                                        java.lang.Class type)

Convert value to type.

Parameters:

value - Object

type - destination

Returns:

conversion result

getValue

public static java.lang.Object getValue(java.lang.Object bean,
                                        java.beans.PropertyDescriptor propertyDescriptor,
                                        int index)

Returns the index'th element of the bean's property represented by the supplied property descriptor.

Parameters:

bean - to read

propertyDescriptor - indicating what to read

index - int

Returns:

Object

setValue

public static void setValue(java.lang.Object bean,
                            java.beans.PropertyDescriptor propertyDescriptor,
                            int index,
                            java.lang.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.

Parameters:

bean - to edit

propertyDescriptor - indicating what to set

index - int

value - to set

getValue

public static java.lang.Object getValue(java.lang.Object object)

If the parameter is a container, opens the container and return the contents. The method is recursive.

Parameters:

object - to read

Returns:

Object

getDynamicPropertyHandler

public static DynamicPropertyHandler getDynamicPropertyHandler(java.lang.Class clazz)

Returns a shared instance of the dynamic property handler class returned by getDynamicPropertyHandlerClass().

Parameters:

clazz - to handle

Returns:

DynamicPropertyHandler

getAccessibleMethod

public static java.lang.reflect.Method getAccessibleMethod(java.lang.reflect.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

Returns:

Method

getAccessibleMethodFromInterfaceNest

private static java.lang.reflect.Method getAccessibleMethodFromInterfaceNest(java.lang.Class clazz,
                                                                             java.lang.String methodName,
                                                                             java.lang.Class[] parameterTypes)

Return an accessible method (that is, one that can be invoked via reflection) that implements the specified method, by scanning through all implemented interfaces and subinterfaces. If no such Method can be found, return null.

Parameters:

clazz - Parent class for the interfaces to be checked

methodName - Method name of the method we wish to call

parameterTypes - The parameter type signatures

Returns:

Method