1、About documentBuilderFactory API description

1）、 javax.xml.parsers 包DocumentBuilderFactory创建DOM模式的解析器对象, DocumentBuilderFactory是抽象工厂类，不能直接实例化，但是有newInstance方法


2）、DocumentBuilderFactory.newInstance() 得到创建 DOM 解析器的工厂

 

 

 

DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance()

 

3）、newDocumentBuilder方法得到 DOM 解析器对象

 

 

 

 

DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();

 

4)、DOM解析器解析输入流，这里可以是XML，文档转化为输入流，或者字符串转为ByteArrayInputStream,DOM 解析器对象的 parse() 方法解析 XML 文档，得到代表整个文档的 Document 对象

 

 

InputStream is = new FileInputStream("xxx.xml");
documentBuilder.parse(is);
documentBuilder.parse(new ByteArrayInputStream(str.getBytes())); 

 
5)、得到 XML 文档的根节点

 

Element rootElement = document.getDocumentElement();

6)、得到节点的子节点

 

 

 

NodeList studentInfo = appElement.getChildNodes();

 

 

 

 

2、Test Demo

 

 

 

 

Student.java文件

package com.parse.doc;public class Student {public String name;public String age;public String sex;public Student() {}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getAge() {return age;}public void setAge(String age) {this.age = age;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}@Overridepublic String toString() {return "name=" + name + ", age=" + age + ", sex=" + sex;}
}

ParseXml.java文件

package com.parse.doc;import java.io.ByteArrayInputStream;
import java.util.ArrayList;
import java.util.List;import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;public class ParseXml {public static String xml = "<Students><student><name><![CDATA[陈喻]]></name><age><![CDATA[26]]></age><sex><![CDATA[男]]></sex></student><student><name><![CDATA[陈彩凤]]></name><age><![CDATA[25]]></age><sex><![CDATA[女]]></sex></student><student><name><![CDATA[陈紫宣]]></name><age><![CDATA[2]]></age><sex><![CDATA[女]]></sex></student><student><name><![CDATA[陈紫曦]]></name><age><![CDATA[7个月]]></age><sex><![CDATA[女]]></sex></student></Students>";public static final String STUDENT = "student";public static final String NAME = "name";public static final String AGE = "age";public static final String SEX = "sex";public static void main(String args[]) {List<Student> students = parseXmlByDoc(xml);if (students != null && students.size() > 0) {for (Student student : students) {System.out.println(student);}} else {System.out.println("students size is 0");}}public static List<Student> parseXmlByDoc(String str) {if (str == null || "".equals(str)) {System.out.println("str is null or ''");return null;}DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();List<Student> students = new ArrayList<Student>();DocumentBuilder documentBuilder;try {documentBuilder = documentBuilderFactory.newDocumentBuilder();Document document = documentBuilder.parse(new ByteArrayInputStream(str.getBytes()));Element rootElement = document.getDocumentElement();NodeList studentNodeList = rootElement.getElementsByTagName(STUDENT);for (int i = 0; i < studentNodeList.getLength(); i++) {Element appElement = (Element) studentNodeList.item(i);NodeList studentInfo = appElement.getChildNodes();Student student = new Student();for(int j = 0; j < studentInfo.getLength(); j++) { Element element = (Element) studentInfo.item(j);String appAttr = element.getTagName();switch (appAttr) {case NAME:student.setName(element.getTextContent());break;case AGE:student.setAge(element.getTextContent());break;case SEX:student.setSex(element.getTextContent());break;default:break;} }students.add(student);}} catch (Exception e) {e.printStackTrace();return null;}return students;}
}

 

 

 

 

3、Running results

 

name=陈喻, age=26, sex=男
name=陈彩凤, age=25, sex=女
name=陈紫宣, age=2, sex=女
name=陈紫曦, age=7个月, sex=女