Question

我想根据用户选择下载office文件，pdf文件，图像文件，zip文件，dll文件，exe文件。所以，我想从jsp页面下载这些文件类型。

这是jsp代码snippt：

<% 
String filename = "Sample1.docx"; 
String filepath = "e:\\temp\\"; 
response.setContentType("APPLICATION/OCTET-STREAM"); 
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();
%>

但是在下载office文件，图像文件时会出现一些错误。当我打开下载的文件时，它会显示“文件可能已损坏”。

有什么常用的方法可以在jsp中下载所有类型的文件吗？

Answer 1

您的问题是JSP中的out变量是JspWriter，这是一个字符流，因此您的二进制文件会被更改。对于这个特定目的，直接使用servlet会好得多。

Answer 2

好吧，从不同浏览器下载文件时存在一些问题。我的示例关注MSIE和Mozilla类型的浏览器所需的处理

public HttpServletResponse getFile (HttpServletRequest request ,HttpServletResponse httpServletResponse, .......){
          HttpServletResponse response = httpServletResponse;
          InputStream in =/*HERE YOU READ YOUR FILE AS BinaryStream*/

          String filename = "";
          String agent = request.getHeader("USER-AGENT");
          if (agent != null && agent.indexOf("MSIE") != -1)
          {
            filename = URLEncoder.encode(/*THIS IS THE FILENAME SHOWN TO THE USER*/, "UTF8");
            response.setContentType("application/x-download");
            response.setHeader("Content-Disposition","attachment;filename=" + filename);
          }
          else if ( agent != null && agent.indexOf("Mozilla") != -1)
          {
            response.setCharacterEncoding("UTF-8");
            filename = MimeUtility.encodeText(/*THIS IS THE FILENAME SHOWN TO THE USER*/, "UTF8", "B");
            response.setContentType("application/force-download");
            response.addHeader("Content-Disposition", "attachment; filename=\"" + filename + "\"");
          }


          BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream());
          byte by[] = new byte[32768];
          int index = in.read(by, 0, 32768);
          while (index != -1) {
              out.write(by, 0, index);
              index = in.read(by, 0, 32768);
          }
          out.flush();

          return response;
}

检查出来

<强>已更新

Answer 3

问题在于JSP的“Out.write”，它无法写入字节流......

用servlet替换jsp文件......

代码段是：

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    try {
        String filename = (String) request.getAttribute("fileName");
        response.setContentType("application/octet-stream");
        response.setHeader("Content-Disposition",
                "attachment;filename="+filename);

        File file = new File(filename);
        FileInputStream fileIn = new FileInputStream(file);
        ServletOutputStream out = response.getOutputStream();

        byte[] outputByte = new byte[(int)file.length()];
        //copy binary contect to output stream
        while(fileIn.read(outputByte, 0, (int)file.length()) != -1)
        {
        out.write(outputByte, 0, (int)file.length());
        }
     }

现在你可以下载所有类型的文件......

是否有一种在jsp中下载所有类型文件的常用方法？

3 个答案: