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);
     }

     }

 }