java下载-opera浏览器修改后缀问题

       response.setContentType("text/html;charset=utf-8");

       request.setCharacterEncoding("UTF-8");

       java.io.BufferedInputStream bis = null;

       java.io.BufferedOutputStream bos = null;

       String filePath = request.getParameter("filePath");

       filePath = Tools.encodeStr(filePath, "iso-8859-1", "utf-8");

       filePath = request.getSession().getServletContext().getRealPath(filePath);

       String fileName = request.getParameter("fileName");

       fileName = Tools.encodeStr(fileName, "iso-8859-1", "utf-8");

       try {

           long fileLength = new File(filePath).length();

　　　　//定义下载类型（也就是保存文件的后缀名，根据浏览器不同，规范严格的会把后缀改成设置的后缀）

           //定义后缀为.exe的文件

           response.setContentType("application/x-msdownload;");

　　　　//定义后缀为Java的文件(设置为Java后缀,opera就不会出现更改后缀的问题)

　　　　response.setContentType("application/java");

           response.setHeader("Content-disposition", "attachment; filename=" + new String(fileName.getBytes("GBK"),"ISO8859-1"));

           response.setHeader("Content-Length", String.valueOf(fileLength));

          

           bis = new BufferedInputStream(new FileInputStream(filePath));

           bos = new BufferedOutputStream(response.getOutputStream());

           byte[] buff = new byte[2048];

           int bytesRead;

           while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {

              bos.write(buff, 0, bytesRead);

           }

       } catch (Exception e) {

           e.printStackTrace();

       } finally {

           if (bis != null)

              bis.close();

           if (bos != null)

              bos.close();

       }

}