Dom解析XMl文档

XMl文档

<?xml version = "1.0" encoding = "UTF-8"?>
<books>
    <book bookno="001">
        <title> java 编程</title>
        <author> me </author>
        <price> 80 </price>
    </book>
    <book bookno="002">
        <title> android 编程</title>
        <author> me </author>
        <price> 70 </price>
    </book>
</books>

Dom解析程序

/*
 * Dom 将文档进行扫描建立树状document文档有全部的节点  根节点为文档 子节点为每个实体 每个实体有属性子节点
 * 对document 文档进行遍历 输出文档内容
 * */
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;


import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class DomXMLParser implements XMLParser {

    @Override
    public List<Book> parseXML(String filename) {
    List<Book> list = new ArrayList<Book>();
    //文档生成器工厂对象
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    Document document = null;
    try {
        //文档生成器对象
        DocumentBuilder builder = factory.newDocumentBuilder();
        //解析得到文档对象
        document = builder.parse(new File(filename));
    } catch (ParserConfigurationException e) {
        e.printStackTrace();
    } catch (SAXException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    //导入w3c中的node类
    Node rootnode = (Node) document.getDocumentElement();
    //获得book元素列表
    NodeList bookelementlist = rootnode.getChildNodes();
    for(int i = 0 ;i<bookelementlist.getLength();i++){
        // 获得单个book元素
        Node bookelement = (Node) bookelementlist.item(i);
        if(bookelement.getNodeName().equals("book")){
            Book book =new Book();
            NamedNodeMap map = bookelement.getAttributes();
            Node booknonode =  (Node) map.getNamedItem("bookno");
            String booknostring = booknonode.getNodeValue();
            book.setNo(booknostring.trim());
            NodeList subbookelementlist = bookelement.getChildNodes();
            for(int j = 0;j<subbookelementlist.getLength();j++){
                Node subelementnode = (Node) subbookelementlist.item(j);
                String subelementnamestring = subelementnode.getNodeName();
                if(subelementnamestring.equals("title")){
                    book.setAuthor((subelementnode.getTextContent().trim()));    
                }
                if(subelementnamestring.equals("author")){
                    book.setTitle(subelementnode.getTextContent().trim());    
                }
                if(subelementnamestring.equals("price")){
                    book.setPrice(Double.parseDouble(subelementnode.getTextContent().trim()));    
                }
            }
            list.add(book);
        }
    }
        return list;
    }

    public static void main(String[] args) {
    DomXMLParser parser = new DomXMLParser();
    List<Book> list = parser.parseXML("src\book.xml");
    
    System.out.println("解析结果：");
    for(Book book:list){
        System.out.println(book);
    }

    }

}