/**
      * 输出xml和解析xml的工具类
      *@ClassName:XmlUtil
      *@author: chenyoulong  Email: chen.youlong@payeco.com
      *@date :2012-9-29 上午9:51:28
      *@Description:TODO
      */
     public class XmlUtil{
         /**
          * java 转换成xml
          * @Title: toXml 
          * @Description: TODO 
          * @param obj 对象实例
          * @return String xml字符串
          */
         public static String toXml(Object obj){
             XStream xstream=new XStream();
 //            XStream xstream=new XStream(new DomDriver()); //直接用jaxp dom来解释
 //            XStream xstream=new XStream(new DomDriver("utf-8")); //指定编码解析器,直接用jaxp dom来解释
             
             ////如果没有这句，xml中的根元素会是<包.类名>；或者说：注解根本就没生效，所以的元素名就是类的属性
             xstream.processAnnotations(obj.getClass()); //通过注解方式的，一定要有这句话
             return xstream.toXML(obj);
         }
         
         /**
          *  将传入xml文本转换成Java对象
          * @Title: toBean 
          * @Description: TODO 
          * @param xmlStr
          * @param cls  xml对应的class类
          * @return T   xml对应的class类的实例对象
          * 
          * 调用的方法实例：PersonBean person=XmlUtil.toBean(xmlStr,PersonBean.class);
          */
         public static <T> T  toBean(String xmlStr,Class<T> cls){
             //注意：不是new Xstream(); 否则报错：java.lang.NoClassDefFoundError: org/xmlpull/v1/XmlPullParserFactory
             XStream xstream=new XStream(new DomDriver());
             xstream.processAnnotations(cls);
             T obj=(T)xstream.fromXML(xmlStr);
             return obj;            
         } 
 
        /**
          * 写到xml文件中去
          * @Title: writeXMLFile 
          * @Description: TODO 
          * @param obj 对象
          * @param absPath 绝对路径
          * @param fileName    文件名
          * @return boolean
          */
       
         public static boolean toXMLFile(Object obj,String absPath,String fileName ){
             String strXml = toXml(obj);
             String filePath = absPath + fileName;
             File file = new File(filePath);
             if(!file.exists()){
                 try {
                     file.createNewFile();
                 } catch (IOException e) {
                     log.error("创建{"+ filePath +"}文件失败!!!" + Strings.getStackTrace(e));
                     return false ;
                 }
             }// end if 
             OutputStream ous = null ;
             try {
                 ous = new FileOutputStream(file);
                 ous.write(strXml.getBytes());
                 ous.flush();
             } catch (Exception e1) {
                 log.error("写{"+ filePath +"}文件失败!!!" + Strings.getStackTrace(e1));
                 return false;
             }finally{
                 if(ous != null )
                     try {
                         ous.close();
                     } catch (IOException e) {
                         log.error("写{"+ filePath +"}文件关闭输出流异常!!!" + Strings.getStackTrace(e));
                     }
             }
             return true ;
         }
         
         /**
          * 从xml文件读取报文
          * @Title: toBeanFromFile 
          * @Description: TODO 
          * @param absPath 绝对路径
          * @param fileName 文件名
          * @param cls
          * @throws Exception 
          * @return T
          */
         public static <T> T  toBeanFromFile(String absPath,String fileName,Class<T> cls) throws Exception{
             String filePath = absPath +fileName;
             InputStream ins = null ;
             try {
                 ins = new FileInputStream(new File(filePath ));
             } catch (Exception e) {
                 throw new Exception("读{"+ filePath +"}文件失败！",e);
             }
             
             String encode = useEncode(cls);
             XStream xstream=new XStream(new DomDriver(encode));
             xstream.processAnnotations(cls);
             T obj =null;
             try {
                 obj = (T)xstream.fromXML(ins);
             } catch (Exception e) {
                 // TODO Auto-generated catch block
                 throw new Exception("解析{"+ filePath +"}文件失败！",e);
             }
             if(ins != null)
                 ins.close();
             return obj;            
         } 
         
     }