1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.commons.jxpath; 19 20 import java.io.Serializable; 21 22 /** 23 * Pointers represent locations of objects and their properties in Java object graphs. JXPathContext has methods 24 * ({@link JXPathContext#getPointer(java.lang.String) getPointer()} and ({@link JXPathContext#iteratePointers(java.lang.String) iteratePointers()}, which, given 25 * an XPath, produce Pointers for the objects or properties described the path. For example, {@code ctx.getPointer 26 * ("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 27 * value of {@code 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 28 * is the value of the property "aMap" of the root object. 29 */ 30 public interface Pointer extends Cloneable, Comparable, Serializable { 31 32 /** 33 * Returns a string that is a proper "canonical" XPath that corresponds to this pointer. Consider this example: 34 * <p> 35 * {@code Pointer ptr = ctx.getPointer("//employees[firstName = 'John']") 36 * } 37 * </p> 38 * <p> 39 * The value of {@code ptr.asPath()} will look something like {@code "/departments[2]/employees[3]"}, so, basically, it represents the concrete location(s) 40 * 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 41 * an XPath that looks like this: {@code " 42 * /departments[@name = 'HR']/employees[3]"}. 43 * 44 * @return String path 45 */ 46 String asPath(); 47 48 /** 49 * Pointers are cloneable. 50 * 51 * @return cloned Object 52 */ 53 Object clone(); 54 55 /** 56 * 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 57 * is. 58 * <p> 59 * For example, for an XML element, getNode() will return the element itself rather than the text it contains. 60 * </p> 61 * 62 * @return Object node 63 */ 64 Object getNode(); 65 66 /** 67 * Returns the node this pointer is based on. 68 * 69 * @return Object 70 */ 71 Object getRootNode(); 72 73 /** 74 * Returns the value of the object, property or collection element this pointer represents. May convert the value to one of the canonical InfoSet types: 75 * String, Number, Boolean, Set. 76 * <p> 77 * For example, in the case of an XML element, getValue() will return the text contained by the element rather than the element itself. 78 * </p> 79 * 80 * @return Object value 81 */ 82 Object getValue(); 83 84 /** 85 * Modifies the value of the object, property or collection element this pointer represents. 86 * 87 * @param value value to set 88 */ 89 void setValue(Object value); 90 }