SAX解析XML文件

  import javax.xml.parsers.ParserConfigurationException;
  import javax.xml.parsers.SAXParser;
  import javax.xml.parsers.SAXParserFactory;
  /**
   * 1.新建一个SAX解析工厂实例
   * 2.new一个解析器
   * 3.new一个解析处理器
   * 4.解析文件
   * 5.获取信息
  * @author Administrator
  *
  */
 public class SAXParserDemo {
 
     public static void main(String[] args) {
         SAXParserFactory factory = SAXParserFactory.newInstance();// 工厂模式，单例模式
         try {
             /* 获得一个sax解析器 */
             SAXParser parser = factory.newSAXParser();
             /* 解析器解析这个文件，new一个解析处理器 */
             SAXParserHandler sax = new SAXParserHandler();
             parser.parse("books.xml", sax);
             System.out.println("几本书：" + sax.booklist.size());
             
             for (Book book : sax.booklist) {
                 System.out.println(book.getId());
                 System.out.println(book.getName());
                 System.out.println(book.getPrice());
                 System.out.println(book.getAuthor());
                 
             }
 
         } catch (ParserConfigurationException e) {

            e.printStackTrace();
         } catch (Exception e) {
 
             e.printStackTrace();
         } 
     }
 
 }

package SAXParser1;

import java.util.ArrayList;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
 * @author xuhua 解析处理器
 * 1.重写方法
 */
public class SAXParserHandler extends DefaultHandler {
    /* 全局变量 */
    Book book;
    String value;
    ArrayList<Book> booklist = new ArrayList<Book>();

    /**
     * 解析开始
     */
    @Override
    public void startDocument() throws SAXException {
        super.startDocument();
        System.out.println("parse start");
    }

    /**
     * 解析结束
     */
    @Override
    public void endDocument() throws SAXException {
        super.endDocument();
        System.out.println("parse end");
    }

    /**
     * 开始解析标签
     * qName:标签名字  Attributes：属性
     */
    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {

        super.startElement(uri, localName, qName, attributes);

        if (qName.equals("book")) {
            book = new Book();
            String id = attributes.getValue("id");//获取id属性值
            System.out.println(id);

            /* 获取属性名与属性值 */
            int num = attributes.getLength(); // 属性个数
            for (int i = 0; i < num; i++) {
                System.out.println("属性名：" + attributes.getQName(i));
                System.out.println("属性值：" + attributes.getValue(i));
                /* 把id属性值set进book实体中 */
                if (attributes.getQName(i).equals("id")) {
                    book.setId(attributes.getValue(i));
                }
            }
        }

        System.out.println("属性名：" + qName);
    }

    /**
     * 结束标签解析
     */
    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {

        super.endElement(uri, localName, qName);
        if (qName.equals("book")) {
            booklist.add(book);
            book = null;
            System.out.println("==============结束遍历某一本书的内容=============");
        }
        /* id为book节点的属性，其他为节点值 */
        // else if(qName.equals("id"))
        // {
        // book.setId(value);
        // }
        else if (qName.equals("name")) {
            book.setName(value);
        } else if (qName.equals("price")) {
            book.setPrice(value);
        } else if (qName.equals("author")) {
            book.setAuthor(value);
        }
        System.out.println(qName + "元素结束");

    }

    /**
     * 获取节点值
     */
    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {

        super.characters(ch, start, length);
        /**/
        value = new String(ch, start, length);
        // if(value.trim()!=null)
        if (!value.trim().equals("")) // 标签之间存在空格
            System.out.println(value);
    }

}

package SAXParser1;

public class Book {
    private String id;
    private String name;
    private String price;
    private String author;
    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 getPrice() {
        return price;
    }
    public void setPrice(String price) {
        this.price = price;
    }
    public String getAuthor() {
        return author;
    }
    public void setAuthor(String author) {
        this.author = author;
    }
    
}

<?xml version="1.0" encoding="utf-8"?>
<bookstore>
    <book id="1">
        <name>java入门</name>
        <price>80</price>
        <author>张思</author>
    </book>
    <book id="2">
        <name>java进阶</name>
        <price>90</price>
        <author>叶东</author>
    </book>

</bookstore>