excel can not open the downloaded file through jsp

2019-06-14 15:06发布

问题:

this is the code for download excel file on browser but when i open it excel throw a error "Excel can not open the file 'Location.xlsx' because the file format or file extension is not valid. verify that the file has not been corrupted and that the file extension matches the format of the file" but when i simply create this file its opening only this error is coming when i perform download operation and i am using poi jar for excel file creation...???

<html>

    <body>
        <%
   LocationDownload.downloadLocation();
%>
<% 
  String filename = "Location.xlsx";   
  String filepath = "C:\\Users\\dsingh\\GlassFish_Server\\glassfish\\domains\\domain1\\config\\";   
  response.setContentType("application/vnd.ms-excel");   
  response.setHeader("Content-Disposition","attachment; filename=" + filename);   

  java.io.FileInputStream fileInputStream=new java.io.FileInputStream(filepath + filename);  

  int i;   
  while ((i=fileInputStream.read()) != -1) {  
    out.write(i);   
   }   
  fileInputStream.close();   
%>   

    </body>
</html>

回答1:

First move your File Download coding to Servlet (don't do inside JSP file)..

Check this code it will help.. It is working with me for the same purpose as u require.

package edu.zukrah.servlets;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class FileDownload
 */
@WebServlet("/FileDownload")
public class FileDownload extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
         File f = new File ("E:/pdftest/" + request.getParameter("file") );
         //set the content type(can be excel/word/powerpoint etc..)

         String type = request.getParameter("type");
         response.setContentType (type);

         //set the header and also the Name by which user will be prompted to save
         response.setHeader ("Content-Disposition", "attachment; filename=\""+request.getParameter("file")+"\"");

         //get the file name
         String name = f.getName().substring(f.getName().lastIndexOf("/") + 1, f.getName().length());

         //OPen an input stream to the file and post the file contents thru the 
         //servlet output stream to the client m/c
          InputStream in = new FileInputStream(f);

        try{
              ServletOutputStream outs = response.getOutputStream();

              int bytesRead;
              byte[] buf = new byte[4 * 1024]; // 4K buffer

              try {
                   while ((bytesRead = in.read(buf)) != -1){ 
                       outs.write(buf, 0, bytesRead);
                   }

              } catch (IOException ioe) {
                  ioe.printStackTrace(System.out);
              }

              System.out.printf(name + ",  %.2f kbs downloaded, %.2f mbs downloaded   \n", 
                                (f.length()/((double)(1024))), 
                                (f.length()/((double)(1024*1024))));

              outs.flush();
              outs.close();
              in.close(); 
        }catch(Exception e){
            e.printStackTrace();
        }
    }


}