文件下载:

public void doGet(HttpServletRequest request, HttpServletResponse response) 
            throws ServletException, IOException { 
         
        String fileName = request.getParameter("path"); 
        //处理中文乱码问题 
        fileName = new String(fileName.getBytes("ISO-8859-1"),"utf-8"); 
        //得到文件保存路径 
        String filePath = this.getServletContext().getRealPath("/WEB-INF/download")+"\\"+fileName; 
         
        File file = new File(filePath); 
        //如果文件不存在 
        if(!file.exists()){ 
            System.out.println("文件不存在"); 
            return; 
        } 
         
        if(request.getHeader("User-Agent").contains("MSIE")){//是IE浏览器 
            //这样处理 
            fileName = new String(fileName.getBytes("gbk"),"ISO-8859-1"); 
        }else{ 
            //其他浏览器这样处理 
            fileName = new String(fileName.getBytes("utf-8"),"ISO-8859-1"); 
        } 
         
        //设置响应头信息，并在浏览器弹出框中设置显示的文件名 
        response.addHeader("content-disposition", "attachment;filename="+fileName); 
        //使用commons包类实现下载 
        IOUtils.copy(new FileInputStream(file), response.getOutputStream()); 
         
    } 
 
    public void doPost(HttpServletRequest request, HttpServletResponse response) 
            throws ServletException, IOException { 
        doGet(request, response); 
    }