java读取xml文件

    DocumentBuilderFactory documentBuildFactory=DocumentBuilderFactory.newInstance();
    DocumentBuilder documentBuilder=documentBuildFactory.newDocumentBuilder();

Document document=documentBuilder.parse(new File("bin/newxml.xml"));       

package com.xml;

import java.io.File;
import java.io.IOException;

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

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

public class ReadXml {
    public static void main(String[] args){
        
        try {
            
            
            DocumentBuilderFactory documentBuildFactory=DocumentBuilderFactory.newInstance();
            DocumentBuilder documentBuilder=documentBuildFactory.newDocumentBuilder();
            Document document=documentBuilder.parse(new File("bin/newxml.xml"));
            
            //System.out.println(document.toString());这样直接输出的到的是null，没有解析
            
            
            Element root=document.getDocumentElement();//获取根对象
            System.out.println(root.getTagName()+" cat="+root.getAttribute("cat"));
            NodeList lan= root.getElementsByTagName("lan");
            for(int j=0;j<lan.getLength();j++){
                System.out.println("---------------------");
                Element list=(Element) lan.item(j);
                System.out.println(list.getNodeName()+" id="+list.getAttribute("id"));
                
                /*Element name=(Element) list.getElementsByTagName("name").item(0);
                System.out.println("name="+name.getTextContent());
                Element ide=(Element) list.getElementsByTagName("ide").item(0);
                System.out.println("ide="+ide.getTextContent());*/
                
                NodeList clist=list.getChildNodes();
                for(int i=0;i<clist.getLength();i++){
                    Node c= clist.item(i);
                    if(c instanceof Element){
                        System.out.println(c.getNodeName()+"="+c.getTextContent());
                    }
                    
                }
            }
            
    
            
            
            
        } catch (ParserConfigurationException e) {
            e.printStackTrace();
        } catch (SAXException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}