02.使用dom4j生成xml后， 不同的处理方式

package gov.mof.fasp.ifmis.acal.common.expxml;import gov.mof.framework.util.DateUtil;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileWriter;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.io.StringReader;import java.io.UnsupportedEncodingException;import java.math.BigDecimal;import java.text.DecimalFormat;import javax.servlet.http.HttpServletResponse;import oracle.sql.DATE;import org.dom4j.Document;import org.dom4j.io.OutputFormat;import org.dom4j.io.XMLWriter;public class ExpXmlUtil {    /**     * 构造方法设置为私有.     */    private ExpXmlUtil() {        super();    }    /**     * 导出凭证报文xml方法.     * @param path --     * @param tmpname     * @param columns     * @param dataList     * @return     * @throws IOException      */    public static String expExcelTemplate(String path, String tmpname,Document document, HttpServletResponse response) throws IOException {        /*         *第一种处理方式：xml文件保存到服务器          *///       if (tmpname == null) {//            tmpname = "";//        }//        if (path == null || "".equals(path)) {//            path = new File("").getAbsolutePath();//            path = path.replaceAll("\\\\", "/");//        }//        path += "/cal/impexp/expfilebak/";//        File f = new File(path);//        f.mkdirs();//        String filename = tmpname + ".xml";//        path += filename;//        // 封装xml报文数据//        OutputFormat format = OutputFormat.createPrettyPrint();//        format.setEncoding("utf-8");// 设置XML文件的编码格式//        format.setNewLineAfterDeclaration(false);//声明之后不换行//      //format.setSuppressDeclaration(true);// 不输出头信息//      format.setIndent(false); //设置是否缩进//      //format.setIndent(" "); //以空格方式实现缩进//      format.setNewlines(true); //设置是否换行//        //        XMLWriter writer = null;//        try {//          writer = new XMLWriter(new FileWriter(path), format);//写入指定的文件//          writer.write(document);//      } catch (IOException e) {//          path="";//          e.printStackTrace();//      } finally {//          try {//              writer.close();//          } catch (IOException e) {//              e.printStackTrace();//          }//      }//        return path;        /*         *第二种处理方式：返回页面xml格式          */        ByteArrayOutputStream baos = new ByteArrayOutputStream();        OutputFormat format = OutputFormat.createPrettyPrint();        format.setEncoding("UTF-8");        format.setNewLineAfterDeclaration(false);//声明之后不换行        format.setNewlines(true); //设置是否换行        XMLWriter writer;        try {            writer = new XMLWriter(baos, format);            writer.write(document);            writer.flush();            writer.close();            String fileName = tmpname + DateUtil.getCurrentDateStr(DateUtil.C_DATA_PATTON_YYYYMMDD) + ".xml";            String dispositionHeader = "attachment;filename=" + new String(fileName.getBytes(), "iso8859-1");            // 发送中文文件名的响应头信息            response.setHeader("Content-Disposition", dispositionHeader);            response.setHeader("Content-Type", "application/x-msdownload; charset=gbk");            OutputStream out = response.getOutputStream();            out.write(baos.toByteArray());            out.flush();            out.close();        } catch (UnsupportedEncodingException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }        /*         *第三种处理方式： 同上         *///        InputStream fis = new ByteArrayInputStream(document.asXML().getBytes("utf-8"))  ;//        byte[] buffer = new byte[fis.available()];//        fis.read(buffer);//        fis.close();//        response.reset();//        // 先去掉文件名称中的空格,然后转换编码格式为utf-8,保证不出现乱码,这个文件名称用于浏览器的下载框中自动显示的文件名//        response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.replaceAll(" ", "").getBytes(),"iso8859-1"));//        OutputStream out = new BufferedOutputStream(response.getOutputStream());//        response.setContentType("application/octet-stream");//        out.write(buffer);// 输出文件//        out.flush();//        out.close();        return null;    }    /**     * 格式化金额.     * @param amt --金额     * @return     */    public static String numFormat(String amt) {        DecimalFormat df = new DecimalFormat("#0.00");        BigDecimal amtbd = new BigDecimal(amt);        return df.format(amtbd);    }}