使用Dom4j解析XML文件

      与利用DOM、SAX、JAXP机制来解析xml相比，DOM4J 表现更优秀，具有性能优异、功能强大和极端易用使用的特点，只要懂得DOM基本概念，就可以通过dom4j的api文档来解析xml。dom4j是一套开源的api。实际项目中，往往选择dom4j来作为解析xml的利器。

所用jar包：dom4j-1.6.1.jar

 

常用API

class org.dom4j.io.SAXReader

• read  提供多种读取xml文件的方式，返回一个Domcument对象

interface org.dom4j.Document

• iterator  使用此法获取node
• getRootElement  获取根节点

interface org.dom4j.Node

• getName  获取node名字，例如获取根节点名称为bookstore
• getNodeType  获取node类型常量值，例如获取到bookstore类型为1——Element
• getNodeTypeName  获取node类型名称，例如获取到的bookstore类型名称为Element

interface org.dom4j.Element

• attributes  返回该元素的属性列表
• attributeValue  根据传入的属性名获取属性值
• elementIterator  返回包含子元素的迭代器
• elements  返回包含子元素的列表

interface org.dom4j.Attribute

• getName  获取属性名
• getValue  获取属性值

interface org.dom4j.Text

• getText  获取Text节点值

interface org.dom4j.CDATA

• getText  获取CDATA Section值

interface org.dom4j.Comment

• getText  获取注释 

 

需要解析的xml文件：people.xml

1 <people city="BeiJing">

2     <student name="Jack" age="10">My name is Jack!</student>

3     <student name="Lucy" age="11">My name is Lucy!</student>

4     <student name="James" age="12"/>

5     <teacher name="Jason" age="25">I am a teacher!</teacher>

6     <teacher name="Michael" age="30">I am a teacher too!</teacher>

7 </people>

people.xml

首先根据xml文档构建javabean：

 1 package bean;

 2 

 3 import java.util.List;

 4 

 5 public class People {

 6     private String city;

 7     private List<Student> student;

 8     private List<Teacher> teacher;

 9     

10     public String getCity() {

11         return city;

12     }

13     public void setCity(String city) {

14         this.city = city;

15     }

16     public List<Student> getStudent() {

17         return student;

18     }

19     public void setStudent(List<Student> student) {

20         this.student = student;

21     }

22     public List<Teacher> getTeacher() {

23         return teacher;

24     }

25     public void setTeacher(List<Teacher> teacher) {

26         this.teacher = teacher;

27     }

28 }

People.java

 1 package bean;

 2 

 3 public class Student {

 4     private String name;

 5     private int age;

 6     private String text;

 7     public String getName() {

 8         return name;

 9     }

10     public void setName(String name) {

11         this.name = name;

12     }

13     public int getAge() {

14         return age;

15     }

16     public void setAge(int age) {

17         this.age = age;

18     }

19     public String getResult() {

20         return text;

21     }

22     public void setResult(String result) {

23         this.text = result;

24     }

25     public Student(String name, int age, String text) {

26         super();

27         this.name = name;

28         this.age = age;

29         this.text = text;

30     }

31 }

Student.java

 1 package bean;

 2 

 3 public class Teacher {

 4     private String name;

 5     private int age;

 6     private String text;

 7     public String getName() {

 8         return name;

 9     }

10     public void setName(String name) {

11         this.name = name;

12     }

13     public int getAge() {

14         return age;

15     }

16     public void setAge(int age) {

17         this.age = age;

18     }

19     public String getResult() {

20         return text;

21     }

22     public void setResult(String result) {

23         this.text = result;

24     }

25     public Teacher(String name, int age, String text) {

26         super();

27         this.name = name;

28         this.age = age;

29         this.text = text;

30     }

31 }

Teacher.java

解析代码如下：

 1 package xml;

 2 

 3 import java.io.File;

 4 import java.net.URISyntaxException;

 5 import java.util.ArrayList;

 6 import java.util.Iterator;

 7 import java.util.List;

 8 

 9 import org.dom4j.Document;

10 import org.dom4j.DocumentException;

11 import org.dom4j.Element;

12 import org.dom4j.io.SAXReader;

13 

14 import bean.People;

15 import bean.Student;

16 import bean.Teacher;

17 

18 public class Dom4jParserXML {

19     public static People parseXml(String xmlPath) {

20         File xmlFile = new File(xmlPath);

21         System.out.println(xmlFile.getPath());

22         

23         if (xmlFile.exists()) {

24             SAXReader reader = new SAXReader();

25             People people = new People();

26             try {

27                 // 读入文档流

28                 Document document = reader.read(xmlFile);

29                 // 获取根节点

30                 Element root = document.getRootElement();

31 

32                 List<Student> students = new ArrayList<Student>();

33                 List<Teacher> teachers = new ArrayList<Teacher>();

34                 

35                 people.setCity(root.attributeValue("city"));

36                 // 解析student节点

37                 for (Iterator<Element> iterator = root

38                         .elementIterator("student"); iterator.hasNext();) {

39                     Element eStudent = iterator.next();

40                     String text = eStudent.getText();

41                     

42                     Student student = new Student(

43                             eStudent.attributeValue("name"),

44                             Integer.parseInt(eStudent.attributeValue("age")),text);

45                     students.add(student);

46                 }

47                 // 解析teacher节点

48                 for (Iterator<Element> iterator = root

49                         .elementIterator("teacher"); iterator.hasNext();) {

50                     Element eTeacher = iterator.next();

51                     String text = eTeacher.getText();

52                     

53                     Teacher teacher = new Teacher(

54                             eTeacher.attributeValue("name"),

55                             Integer.parseInt(eTeacher.attributeValue("age")),text);

56                     teachers.add(teacher);

57                 }

58                 people.setStudent(students);

59                 people.setTeacher(teachers);

60                 

61                 System.out.println("Parse success!");

62             } catch (DocumentException e) {

63                 e.printStackTrace();

64             }

65             return people;

66         } else {

67             System.err.println("File is not exist!");

68             return null;

69         }

70     }

71 

72     public static void main(String[] args) throws URISyntaxException {

73         String xmlPath = "E://xml//people.xml";

74         System.out.println("File full path is " + xmlPath);

75         // 解析people.xml

76         People p = parseXml(xmlPath);

77 

78         // 处理解析结果

79         System.out.println("The city is : " + p.getCity());

80         List<Student> sList = p.getStudent();

81         List<Teacher> tList = p.getTeacher();

82         for (Student s : sList) {

83             System.out.println(s.getName() + "->" + s.getAge() + "->" + s.getResult());

84         }

85         for (Teacher t : tList) {

86             System.out.println(t.getName() + "->" + t.getAge() + "->" + t.getResult());

87         }

88     }

89 }

运行结果：

File full path is E://xml//people.xml

E:\xml\people.xml

Parse success!

The city is : BeiJing

Jack->10->My name is Jack!

Lucy->11->My name is Lucy!

James->12->

Jason->25->I am a teacher!

Michael->30->I am a teacher too!

Result