一段下载功能的代码

public  ActionForward download(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
             throws  Exception  ... {
        this.initActionAttributes(request);
        //System.out.println(uploadForm.getFile().getFileName()+"--size is --"+uploadForm.getFile().getFileSize());
        String tables=new String(request.getParameter("TABLE_NAME").getBytes("ISO8859_1"));
        String table=new String(request.getParameter("TABLE").getBytes("ISO8859_1"));
        String con=new String(request.getParameter("SQL_COND").getBytes("ISO8859_1"));
        String col=new String(request.getParameter("TITLE_CODE").getBytes("ISO8859_1"));
        String colName=new String(request.getParameter("TITLE_NAME").getBytes("ISO8859_1"));
        String rowNum=new String(request.getParameter("ROW_NUM").getBytes("ISO8859_1"));
        String[] columnName = colName.split(",");
        StringBuffer sb=new StringBuffer();
        sb.append("select ").append(col).append(" from ").append(tables).append(" where ").append(con).append(" order by (cust.BUSY_IN_CALL_DURATION + cust.IDLE_IN_CALL_DURATION) desc fetch first "+rowNum+" rows only");
        StringBuffer updateSql=new StringBuffer();
        updateSql.append("update ").append(table).append(" set DOWNLOAD_MARK=1,DOWNLOAD_TIME=current Date where comp_product_no in(select cust.comp_product_no from DMCF_cust_ms cust").append(" where ").append(con).append(" order by (cust.BUSY_IN_CALL_DURATION + cust.IDLE_IN_CALL_DURATION) desc fetch first "+rowNum+" rows only)");
        String fileName = "CustInfo" +
        new SimpleDateFormat("yyyyMMddHHmmss").format(new    java.util.Date()) + ".csv";
         PrintWriter pw = null;
         Sqlca m_Sql = null;
//       保存到客户机上
         response.setContentType("application/octet-stream; charset=gbk");
         response.setHeader("Content-disposition", "attachment; filename="" + fileName + """);
         PrintWriter out1 = null;
         try ...{

             pw = new PrintWriter(new FileOutputStream(fileName));
             out1 = response.getWriter();
             //标题vector
             Vector titleVector = new Vector();
             for (int i = 0; i < columnName.length; i++) ...{
                 titleVector.add(columnName[i]);
             }
             for (int j = 0; j < titleVector.size(); j++) ...{
                 out1.print(new String(String.valueOf(titleVector.elementAt(j)).getBytes("gbk")));
                 if (j == titleVector.size() - 1)
                     out1.println();
                 else
                     out1.print(",");
                 out1.flush();
             }
             
             m_Sql = new Sqlca(new ConnectionEx(Const.DATASOURCE));

             m_Sql.execute(sb.toString());
             String tmpStr;
             while (m_Sql.next()) ...{
                 
                 for (int j = 1; j <= titleVector.size(); j++) ...{
                     tmpStr = "" + m_Sql.getString(j);
                     out1.write(new String(tmpStr.getBytes("gbk")));
                     if (j == titleVector.size())
                         out1.println();
                     else
                         out1.print(",");
                 }
                 out1.flush();
             }
            m_Sql.execute(updateSql.toString());
            m_Sql.commit();
            
         } catch (Exception exception) ...{
             m_Sql.rollback();
             if(m_Sql != null)m_Sql.closeAll();
             exception.printStackTrace();
         } finally ...{
             if(m_Sql != null)m_Sql.closeAll();
             
         }
        
        return mapping.findForward("initAction");
    }