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The source code
/*
* Copyright 1999-2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.jxpath;
import java.io.Serializable;
/**
* Pointers represent locations of objects and their properties
* in Java object graphs. JXPathContext has methods
* ({@link JXPathContext#getPointer(java.lang.String) getPointer()}
* and ({@link JXPathContext#iteratePointers(java.lang.String)
* 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.
*
* @author Dmitri Plotnikov
* @version $Revision: 1.9 $ $Date: 2004/02/29 14:17:42 $
*/
public interface Pointer extends Cloneable, Comparable, Serializable {
/**
* 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.
*/
Object getValue();
/**
* 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.
*/
Object getNode();
/**
* Modifies the value of the object, property or collection element
* this pointer represents.
*/
void setValue(Object value);
/**
* Returns the node this pointer is based on.
*/
Object getRootNode();
/**
* 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]" .
*/
String asPath();
/**
* Pointers are cloneable
*/
Object clone();
}
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