org.apache.commons.jxpath

Interface Pointer

All Superinterfaces:
Cloneable, Comparable, Serializable
Known Implementing Classes:
BeanPointer, BeanPropertyPointer, CollectionPointer, ContainerPointer, DOMAttributePointer, DOMNodePointer, DynaBeanPointer, DynaBeanPropertyPointer, DynamicPointer, DynamicPropertyPointer, JDOMAttributePointer, JDOMNamespacePointer, JDOMNodePointer, LangAttributePointer, NamespacePointer, NodePointer, NullElementPointer, NullPointer, NullPropertyPointer, PropertyOwnerPointer, PropertyPointer, VariablePointer

public interface Pointer
extends Cloneable, Comparable, Serializable

Pointers represent locations of objects and their properties in Java object graphs. JXPathContext has methods (getPointer() and (iteratePointers(), which, given an XPath, produce Pointers for the objects or properties described the the path. For example, ctx.getPointer ("foo/bar") will produce a Pointer that can get and set the property "bar" of the object which is the value of the property "foo" of the root object. The value of ctx.getPointer("aMap/aKey[3]") will be a pointer to the 3'rd element of the array, which is the value for the key "aKey" of the map, which is the value of the property "aMap" of the root object.
Version:
$Revision: 1.9 $ $Date: 2004/02/29 14:17:42 $
Author:
Dmitri Plotnikov

Method Summary

String
asPath()
Returns a string that is a proper "canonical" XPath that corresponds to this pointer.
Object
clone()
Pointers are cloneable
Object
getNode()
Returns the raw value of the object, property or collection element this pointer represents.
Object
getRootNode()
Returns the node this pointer is based on.
Object
getValue()
Returns the value of the object, property or collection element this pointer represents.
void
setValue(Object value)
Modifies the value of the object, property or collection element this pointer represents.

Method Details

asPath

public String asPath()
Returns a string that is a proper "canonical" XPath that corresponds to this pointer. Consider this example:

Pointer ptr = ctx.getPointer("//employees[firstName = 'John']")

The value of ptr.asPath() will look something like "/departments[2]/employees[3]", so, basically, it represents the concrete location(s) of the result of a search performed by JXPath. If an object in the pointer's path is a Dynamic Property object (like a Map), the asPath method generates an XPath that looks like this: " /departments[@name = 'HR']/employees[3]".


clone

public Object clone()
Pointers are cloneable

getNode

public Object getNode()
Returns the raw value of the object, property or collection element this pointer represents. Never converts the object to a canonical type: returns it as is. For example, for an XML element, getNode() will return the element itself rather than the text it contains.

getRootNode

public Object getRootNode()
Returns the node this pointer is based on.

getValue

public Object getValue()
Returns the value of the object, property or collection element this pointer represents. May convert the value to one of the canonical InfoSet types: String, Number, Boolean, Set. For example, in the case of an XML element, getValue() will return the text contained by the element rather than the element itself.

setValue

public void setValue(Object value)
Modifies the value of the object, property or collection element this pointer represents.