使用SAX解析将xml的文件内容结构保存到java对象中

来源：互联网发布：网络优化的目的编辑：程序博客网时间：2024/05/22 12:05

在Java使用Sax解析xml文件中，我们介绍了如何用SAX解析xml文件，接下来我们继续学习如何将一个xml文件的内容结构保存到一个java实例对象中

一、xml文件如下

<?xml version="1.0" encoding="UTF-8"?><bookstore><book id="156"><name>计算机网络</name><author>谢希仁</author><price>39</price><year>2013</year></book><book id="234"><name>计算机操作系统</name><author>佚名</author><price>40</price><year>2013</year><edition>第四版</edition></book><book id="367"><name>计算机组成原理</name><price>35</price><year>2013</year><edition>第三版</edition></book></bookstore>

二、首先，我们要想写一个与xml中的book节点结构相同的实体类Book

public class Book {private String id;private String name;private String author;private String price;private String year;private String edition;public String getId() {return id;}public void setId(String id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getAuthor() {return author;}public void setAuthor(String author) {this.author = author;}public String getPrice() {return price;}public void setPrice(String price) {this.price = price;}public String getYear() {return year;}public void setYear(String year) {this.year = year;}public String getEdition() {return edition;}public void setEdition(String edition) {this.edition = edition;}@Overridepublic String toString() {return "Book [id=" + id + ", name=" + name + ", author=" + author + ", price=" + price + ", year=" + year+ ", edition=" + edition + "]";}}

三、编写DefaultHandler类

使用全局变量来实现不同函数之间的对象共享

public class MyHandler extends DefaultHandler {private String value = null;private List<Book> bookList = new ArrayList<>();private Book book = null;@Overridepublic void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {super.startElement(uri, localName, qName, attributes);if ("book".equals(qName)) {book = new Book();String id = attributes.getValue("id");book.setId(id);}}@Overridepublic void characters(char[] ch, int start, int length) throws SAXException {super.characters(ch, start, length);value = new String(ch, start, length);}@Overridepublic void endElement(String uri, String localName, String qName) throws SAXException {super.endElement(uri, localName, qName);switch (qName) {case "book":bookList.add(book);book = null;break;case "name":book.setName(value);break;case "author":book.setAuthor(value);case "year":book.setYear(value);break;case "edition":book.setEdition(<span style="font-family: Arial, Helvetica, sans-serif; font-size: 12px;">value</span><span style="font-size: 12px; font-family: Arial, Helvetica, sans-serif;">);</span>break;case "price":book.setPrice(value);break;}}public List<Book> getBookList() {return bookList;}public void setBookList(List<Book> bookList) {this.bookList = bookList;}}

四、编写主函数

public class SaxXmlParser {public static void main(String[] args) {// 创建SAXParserFactory实例SAXParserFactory spf = SAXParserFactory.newInstance();try {// 创建SAXParser实例SAXParser parser = spf.newSAXParser();// 创建DefaultHandler实例MyHandler handler = new MyHandler();// 开始解析parser.parse("book.xml", handler);for (Book book : handler.getBookList()) {System.out.println(book);}} catch (ParserConfigurationException | SAXException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

五、控制台输出结果如下

Book [id=156, name=计算机网络, author=谢希仁, price=39, year=2013, edition=null]Book [id=234, name=计算机操作系统, author=佚名, price=40, year=2013, edition=第四版]Book [id=367, name=计算机组成原理, author=null, price=35, year=2013, edition=第三版]

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