使用dom4j和XPath解析XML之例子一

http://blog.csdn.net/antswallow

包括三个文件：studentInfo.xml(待解析的xml文件), Dom4jReadExmple.java(解析的主要类),
TestDom4jReadExmple.java(测试解析的结果) （由于使用csdn
blog自带的代码粘贴工具会朝里加入一些"..."字符，虽然利于查看，但是不利于把代码copy出来运行，而亲自运行代码对程序员来说是很重要的，故
没有使用csdn blog自带的代码粘贴工具来插入代码，而是用着用直白的方式）：

studentInfo.xml


<?xml version="1.0" encoding="gb2312"?>

<students>

<student age="25"><!--如果没有age属性，默认的为20-->

<name>崔卫兵</name>

<college>PC学院</college>

<telephone>62354666</telephone>

<notes>男,1982年生,硕士，现就读于北京邮电大学</notes>

</student>

<student>

<name>cwb</name>

<college
leader="leader1">PC学院</college><!--如果没有leader属性，默认的为
leader-->

<telephone>62358888</telephone>

<notes>男,1987年生,硕士，现就读于中国农业大学</notes>

</student>

<student age="45">

<name>xxxxx</name>

<college
leader="">xxx学院</college>

<telephone>66666666</telephone>

<notes>注视中，注释中</notes>

</student>

<student age="">

<name>yyyyyy</name>

<college leader="学院领导">yyyy学院</college>

<telephone>88888888</telephone>

<notes>注视中111，注释中222</notes>

</student>

</students>

Dom4jReadExmple.java


package dom4jExample.read;

import java.io.File;

import java.util.HashMap;

import
java.util.Iterator;

import java.util.List;

import org.dom4j.Attribute;

import org.dom4j.Document;

import
org.dom4j.Element;

import org.dom4j.io.SAXReader;

/**

*
利用dom4j与XPath进行XML编程

* @author cuiweibing

* @since 2007.8.10

*/

public
class Dom4jReadExmple {

/**

* 利用XPath操作XML文件，打印指定节点或者属性的值

* @param filename String 待操作的XML文件（相对路径或者绝对路径）

*/

public void
printSelectedNodeValue(String filename){

try {

SAXReader
saxReader = new SAXReader();

Document document =
saxReader.read(new File(filename));

//打印所有student节点的属性age值，如果有的话

List
list = document.selectNodes("/students/student/@age
");

Iterator
iter = list.iterator();

while (iter.hasNext()) {

Attribute
attribute = (Attribute) iter.next();

System.out.println("/students/student/@age
："+attribute.getValue());

}

//打印所有college节点值，如果有的话

list =
document.selectNodes("/students/student");

iter = list.iterator();

while
(iter.hasNext()) {

Element bookElement = (Element) iter.next();

Iterator
iterator = bookElement.elementIterator("college");

while
(iterator.hasNext()) {

Element titleElement = (Element)
iterator.next();

System.out.println("/students/student
/college："+titleElement.getText());

}

}

//测试节点的一些方法

list
= document.selectNodes("//telephone");

iter = list.iterator();

while
(iter.hasNext()) {

Element titleElement = (Element)
iter.next();

System.out.print("//telephone：getName:"+titleElement.getName());

System.out.print("
##getNodeType:"+titleElement.getNodeType());

System.out.print("
##getTextTrim:"+titleElement.getTextTrim());

System.out.print("
##getNamespaceURI:"+titleElement.getNamespaceURI());

System.out.print("
##getNodeTypeName:"+titleElement.getNodeTypeName());

System.out.print("
##getQualifiedName:"+titleElement.getQualifiedName());

System.out.print("
##getUniquePath:"+titleElement.getUniquePath());

System.out.println("
##getPath:"+titleElement.getPath());

}

//打印所有name节点值，如果有的话，
与上面college的取法不一样

list =
document.selectNodes("/students/student/name");

iter =
list.iterator();

while (iter.hasNext()) {

Element
titleElement = (Element) iter.next();

System.out.println("/students
/student/name："+titleElement.getText());

}

} catch (Exception
ex) {

ex.printStackTrace();

}

}

}

TestDom4jReadExmple.java


package dom4jExample.read;

/**

* 测试Dom4jReadExmple解析的情况

* @author cuiweibing

*
@since 2007.8.10

*/

public class TestDom4jReadExmple {

public
static void main(String[] args) {

try{

Dom4jReadExmple drb=new Dom4jReadExmple();

//利用XPath操作XML文件，打印想要的属性值

drb.printSelectedNodeValue("studentInfo.xml");

}catch(Exception
ex){

ex.printStackTrace();

}

}

}

运行结果


/students/student/@age
：25

/students/student/@age
：45

/students/student/@age
：

/students
/student/college：PC学院

/students/student/college：PC学院

/students
/student/college：xxx学院

/students/student/college：yyyy学院

//telephone：getName:telephone
##getNodeType:1 ##getTextTrim:62354666 ##getNamespaceURI:
##getNodeTypeName:Element ##getQualifiedName:telephone
##getUniquePath:/students/student[1]/telephone
##getPath:/students/student/telephone

//telephone：getName:telephone
##getNodeType:1 ##getTextTrim:62358888 ##getNamespaceURI:
##getNodeTypeName:Element ##getQualifiedName:telephone
##getUniquePath:/students/student[2]/telephone
##getPath:/students/student/telephone

//telephone：getName:telephone
##getNodeType:1 ##getTextTrim:66666666 ##getNamespaceURI:
##getNodeTypeName:Element ##getQualifiedName:telephone
##getUniquePath:/students/student[3]/telephone
##getPath:/students/student/telephone

//telephone：getName:telephone
##getNodeType:1 ##getTextTrim:88888888 ##getNamespaceURI:
##getNodeTypeName:Element ##getQualifiedName:telephone
##getUniquePath:/students/student[4]/telephone
##getPath:/students/student/telephone

/students/student/name：崔卫兵

/students
/student/name：cwb

/students/student/name：xxxxx

/students/student
/name：yyyyyy