JXPath(1.3) - DOM/JDOM Document Access

xml version="1.0" encoding="utf-8"?> <book> <title>Head First Design Patterns</title> <authors> <author> <firstName>Eric</firstName> <lastName>Freeman</lastName> <gender>F</gender> <birthday>1976-09-14</birthday> </author> <author> <firstName>ElElisabeth</firstName> <lastName>Freeman</lastName> <gender>M</gender> <birthday>1983-03-27</birthday> </author> </authors> <publisher> <name>中国电力出版社</name> <address>北京市XX区YY路Z号</address> <contacts> <contact type=‘tel‘>010－12345678</contact> <contact type=‘fax‘>010－87654321</contact> <contact type=‘email‘>test@163.com</contact> </contacts> </publisher> <isbn>9787508353937</isbn> <price>98</price> </book> book.xml

 

DOM/JDOM Document Access

Document document = // get from book.xml ...
JXPathContext context = JXPathContext.newContext(document);
String aBirthday = (String) context.getValue("book/authors/author[firstName=‘ElElisabeth‘]/birthday");
String pEmail = (String) context.getValue("book/publisher/contacts/contact[@type=‘email‘]");

 

Getting a Value vs. Selecting a Node

JXPathContext 有两组相似的 API：getValue(xpath)/iterate(xpath) 和 selectSingleNode(xpath)/selectNodes(xpath)。对 JavaBeans 和类似的 Java 对象模型，这两组 API 是等效的。但是，对 DOM/JDOM，这两组 API 则有个不同的地方：selectSingleNode(xpath) 和 selectNodes(xpath) 返回的是 Nodes，而 getValue() 和 iterate(xpath) 返回的则是节点的文本内容。
例如，对于相同的 XPath，getValue("/book/isbn") 会返回字符串 "9787508353937"，而 selectSingleNode("/book/isbn") 则返回 Element(<isbn>9787508353937</isbn>)（具体类型取决是 DOM 还是 JDOM）。

JXPath(1.3) - DOM/JDOM Document Access

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