下载文件

关于打开或者下载各种的文件

 

package com.zte.matermanage.action;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import jxl.Workbook;
import jxl.write.Label;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;
import jxl.write.WriteException;
import jxl.write.biff.RowsExceededException;

import org.apache.log4j.Logger;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.actions.MappingDispatchAction;

import com.zte.matermanage.bean.History;
import com.zte.matermanage.common.Constant;
import com.zte.matermanage.common.DataUtil;
import com.zte.matermanage.common.StringUtil;
import com.zte.matermanage.logic.ProductManagerService;

/**
 *
 * @author xiaoyong
 *
 */
public class DownloadAction extends MappingDispatchAction
{
 /**
  * 用于记录日志
  */
 private Logger log = Logger.getLogger(DownloadAction.class) ;
 
 private String filepath = "" ;
 
 String ALLDOWNTYPE = "all" ;
 
 String EXCELTYPE = "excel" ;
 
 String filename = "" ;
 
 String roleid = "" ;
 
 HistoryAction historyAction = null;
 
   public ActionForward execDownload(ActionMapping mapping,
             ActionForm form,
             HttpServletRequest request,
             HttpServletResponse response)
  {
  String type = request.getParameter("type") ;
 
  if(type.equals(ALLDOWNTYPE))
  {
   filename = request.getParameter("filename") ;
   if(StringUtil.checkNull(filename))
   {
    return null;
   }
   filepath = Constant.FILE_PATH + filename ;
  
  }else if(type.equals(EXCELTYPE))
  {
   File f = new File(Constant.FILE_PATH);
   if(!f.exists())
   {
    f.mkdir();
   }
   filepath = Constant.FILE_PATH + DataUtil.getFormateDate("yyyyMMddHHmmss") + Constant.EXCEL_FILE_NAME;
   filename = Constant.EXCEL_FILE_NAME ;
   roleid = request.getParameter("roleid") ;
   String excelHeader [] = excelHead();
   WritableWorkbook wwb;
   try
   {
    wwb = Workbook.createWorkbook(new File(filepath));
    WritableSheet ws = wwb.createSheet("Sheet 1", 0);//sheet1是导出excel分页第1页
        for(int i=0;i<excelHeader.length;i++)
        {
        ws.addCell(new jxl.write.Label(i, 0, excelHeader[i]));//导出后excel中的字段名称,i是列,第一行
        ws.setColumnView(i, 20);
        }
        //从SESSION得到要导出具体值
       List<History> listHistory = (List)request.getSession().getAttribute("listHistory") ;
       ProductManagerService  service = ProductManagerService.getInstance() ;
       historyAction = new HistoryAction() ;
       if(listHistory.size() > 0)
       {
        //根据权限，得到查看材料价格的权限
     String roleGroup = service.queryRoles(roleid);
     int h = 1;
     
     List<History> list = historyAction.historyPriceDisplayPopedom(listHistory,roleGroup) ;
     for(int i = 0 ; i < list.size() ;i++)
     {
      History history = (History)list.get(i);
      
      //只有能被查看价格记录才能被导出
      if(!history.getPrice().equals(Constant.PRICE_DISPLAY))
      {
       ws.addCell(new Label(0,h,history.getModifyUsername()));
       ws.addCell(new Label(1,h,history.getData()));
       ws.addCell(new Label(2,h,history.getMatr_name()));
       ws.addCell(new Label(3,h,history.getPrice()));
       ws.addCell(new Label(4,h,history.getRemark()));
       ws.addCell(new Label(5,h,history.getAuthorize_user()));
       h++ ;
      }
     }
      wwb.write();
         wwb.close();
         response.reset();
       }
   }
   catch (IOException e)
   {
    log.error(e) ;
    request.setAttribute("errorMsg", Constant.SYSTEM_ERROR) ;
    return mapping.findForward("faild") ;
   }
   catch (RowsExceededException e)
   {
    log.error(e) ;
    request.setAttribute("errorMsg", Constant.SYSTEM_ERROR) ;
    return mapping.findForward("faild") ;
   }
   catch (WriteException e)
   {
    log.error(e) ;
    request.setAttribute("errorMsg", Constant.SYSTEM_ERROR) ;
    return mapping.findForward("faild") ;
   }
  }
  //下载指定文件
     try
     {
         BufferedOutputStream bos = null;
         StringBuffer sb = new StringBuffer(50);
         sb.append("attachment;  filename=");
         sb.append(filename);
         response.setContentType("application/x-msdownload;charset=utf-8");
         response.setHeader("Content-Disposition",
                           new String(sb.toString().getBytes(),"ISO8859-1") );
      
         FileInputStream fis = new FileInputStream(new File(filepath));
         bos = new BufferedOutputStream(response.getOutputStream());
         byte[] buffer = new byte[2048];
         int number = 0;
         while ((number = fis.read(buffer)) != -1)
         {
             bos.write(buffer,0,number);
         }

         fis.close();
         bos.close();
     } catch (IOException e)
     {
     log.info(e.getMessage()) ;
        request.setAttribute("errorMsg", Constant.SYSTEM_ERROR) ;
  return mapping.findForward("faild") ;
     }

  return null;
  }
  /**
   * EXCEL 表头信息
   * @return
   */
  public String [] excelHead()
 {
  return new String []{"申请人","申请时间","物料名称","价格","备注","批注人"};
   
 }
}