Java 写入和读取XML文件

package test;

import java.io.File;
import java.io.FileWriter;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

import bean.Area;

/***********************************************
*
*@ author lichong
*@ since 2013-4-19 下午04:41:38 2013
***********************************************/
public class MyXml {

  public void writeXmlDocument(Area obj, List<Area> areaList, String Encode,  
            String XMLPathAndName) {  
        long lasting = System.currentTimeMillis();//效率检测  
 
        try {  
            XMLWriter writer = null;// 声明写XML的对象   
            OutputFormat format = OutputFormat.createPrettyPrint();  
            format.setEncoding(Encode);// 设置XML文件的编码格式  
 
            String filePath = XMLPathAndName;//获得文件地址  
            File file = new File(filePath);//获得文件    
 
            if (file.exists()) {  
                file.delete();  
 
            }  
            // 新建student.xml文件并新增内容  
            Document document = DocumentHelper.createDocument();  
            String rootname = obj.getClass().getSimpleName();//获得类名  
            Element root = document.addElement(rootname + "s");//添加根节点  
            Field[] properties = obj.getClass().getDeclaredFields();//获得实体类的所有属性  
           
            for (Object t : areaList) {                                //递归实体  
                Element secondRoot = root.addElement(rootname);            //二级节点  
               
                for (int i = 0; i < properties.length; i++) {                     
                    //反射get方法      
                    Method meth = t.getClass().getMethod(                     
                            "get" 
                                    + properties[i].getName().substring(0, 1)  
                                            .toUpperCase()  
                                    + properties[i].getName().substring(1));  
                    //为二级节点添加属性，属性值为对应属性的值  
                    secondRoot.addElement(properties[i].getName()).setText(  
                            meth.invoke(t).toString());  
 
                }  
            }  
            //生成XML文件  
            writer = new XMLWriter(new FileWriter(file), format);  
            writer.write(document);  
            writer.close();  
            long lasting2 = System.currentTimeMillis();  
            System.out.println("写入XML文件结束,用时"+(lasting2 - lasting)+"ms");  
        } catch (Exception e) { 
        e.printStackTrace();
            System.out.println("XML文件写入失败");  
        }  
 
    } 
//   /**
//    * 写入的调用
//    * @param args
//    */
//   public static void main(String[] args) {
// MyXml xml=new MyXml();
// Area area1=new Area();
// Area area=new Area();
// area.setAreaNum("001");
// area.setAreaName("北京市");
// area.setId(2);
//
// area.setId(1);
// Area area2=new Area();
// area2.setAreaName("海淀区");
// area2.setAreaNum("002");
//
// area2.setId(1);
// List<Area> areaList=new ArrayList<Area>();
// areaList.add(area);
// areaList.add(area2);
// xml.writeXmlDocument(area1, areaList, "UTF-8", "WebRoot\\WEB-INF\\student.xml");
//
// System.exit(0);
// }
//  
 
  public List<Area> readXML(String XMLPathAndName, Area t) {  
        long lasting = System.currentTimeMillis();//效率检测  
        List<Area> list = new ArrayList<Area>();//创建list集合  
        try {  
            File f = new File(XMLPathAndName);//读取文件  
            SAXReader reader = new SAXReader();  
            Document doc = reader.read(f);//dom4j读取  
            Element root = doc.getRootElement();//获得根节点  
            Element foo;//二级节点  
            Field[] properties = t.getClass().getDeclaredFields();//获得实例的属性  
            //实例的get方法  
            Method getmeth;  
            //实例的set方法  
            Method setmeth;  
              
            for (Iterator i = root.elementIterator(t.getClass().getSimpleName()); i.hasNext();) {//遍历t.getClass().getSimpleName()节点  
                foo = (Element) i.next();//下一个二级节点  
                  
               t=(Area)t.getClass().newInstance();//获得对象的新的实例  
 
               for (int j = 0; j < properties.length; j++) {//遍历所有孙子节点  
                       System.out.println(properties[j].getType().toString());
 
                    //实例的set方法  
                      setmeth = t.getClass().getMethod(  
                            "set" 
                                    + properties[j].getName().substring(0, 1)  
                                            .toUpperCase()  
                                    + properties[j].getName().substring(1),properties[j].getType());  
                  //properties[j].getType()为set方法入口参数的参数类型(Class类型) 
                      System.out.println("set fangfa "+setmeth);
                      System.out.println("获取的值==="+foo.elementText(properties[j].getName()).toString());
                     
                  if(properties[j].getType().toString().equals("int")){
                  setmeth.invoke(t,Integer.parseInt(foo.elementText(properties[j].getName())));//将对应节点的值存入  
                  }
                   if(properties[j].getType().toString().equals("class java.lang.String")){  
                   setmeth.invoke(t,(foo.elementText(properties[j].getName())));//将对应节点的值存入  
                   }
                   
          
                }  
      
                  
                list.add(t);  
            }  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
        long lasting2 = System.currentTimeMillis();  
 
        System.out.println("读取XML文件结束,用时"+(lasting2 - lasting)+"ms");  
        return list;  
    } 
  /**
   * 读取时的调用
   */
public static void main(String[] args) {
MyXml xml=new MyXml();
     Area area=new Area();
     List<Area> list=xml.readXML("WebRoot\\WEB-INF\\student.xml", area);
     System.out.println("读取文件结束");
for(int i =0;i<list.size();i++){ 
Area area2=(Area)list.get(i);
System.out.println(area2.getAreaName());
System.out.println(area2.getAreaNum());
System.out.println(area2.getId());
}  
}
}