反射+jdom+xml例子，经过一番折腾，总算知道反射是啥意思了，真的很感谢帮助我的人，不知道说啥好了，就是感动，我把我做的东西和大家分
建一个文件夹D:\some\directory
Xml类
package   com.cyberobject.study;

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

import   org.jdom.Document;
import   org.jdom.Element;
import   org.jdom.output.Format;
import   org.jdom.output.XMLOutputter;

public   class   Xml   {

/**
  *   向指定的xml文件写数据
  *   @param   FileName   要用到的cell文件模板名
  *   @param   dto   传输数据对象
  *   @throws   ClassNotFoundException  
  *   @throws   IllegalAccessException  
  *   @throws   IllegalArgumentException  
  *   @throws   InstantiationException  
  */
public   void   writeXmlFile(DataTransaction   dto)   throws   ClassNotFoundException,   IllegalArgumentException,   IllegalAccessException,   InstantiationException{

Element   rootElement   =   new   Element( "WorkBook ");
Document   myDocument   =   new   Document(rootElement);

List   dtoObjects   =   dto.getDtoObjects();

for(int   i   =   0   ;   i   <   dtoObjects.size()   ;   i++){

Element   cellFileElement   =   new   Element( "CellFile ");
rootElement.addContent(cellFileElement);

DtoObject   dtoObject   =   (DtoObject)dtoObjects.get(i);

cellFileElement.setAttribute( "name ",dtoObject.getCellFileName()+ ".cell ");

List   objects   =   dtoObject.getObjects();

for(int   j   =   0   ;j   <   objects.size();   j++   ){
Object   object   =   dtoObject.getObjects().get(j);

Element   objElement   =   new   Element( "Object ");
Field   fieldList[]   =   object.getClass().getFields();

for(int   k   =   0   ;   k   <   fieldList.length   ;   k++){
String   fieldName   =   fieldList[k].getName().toString();  
String   fieldValue   =   fieldList[k].get(object).toString();
System.out.print(fieldName+ ": "+fieldValue);
objElement.setAttribute(fieldName,fieldValue.toString());
}
cellFileElement.addContent(objElement);
}

XMLOutputter   output   =   new   XMLOutputter(Format.getPrettyFormat());

try{
File   mydir=new   File( "d:/some/directory/ "+dto.getXmlFileName()+ ".xml ");  
if(!mydir.exists()){
this.createFile( "d:/some/directory/ ",dto.getXmlFileName());
}else{
this.deleteFile( "d:/some/directory/ "+dto.getXmlFileName()+ ".xml ");

FileWriter   fileWriter   =   new   FileWriter( "d:/some/directory/ "+dto.getXmlFileName()+ ".xml ");
output.output(myDocument,fileWriter);
fileWriter.close();
}
}catch(IOException   e){
e.printStackTrace();
}
}
}

/**
  *   删除文件