JavaWeb中文件下载的代码,供参考

//文件下载
@WebServlet("/down")
public class DownLoadServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        //0.跳过权限检查和积分检查
        //1.获取被下载的资源文件名称
        String filename = req.getParameter("fileName");
        System.out.println(filename);
        if (filename != null && "".equals(filename.trim())) {
            //对获取到的参数进行重新编码,因为可能会有中文乱码的问题
            filename = new String(filename.getBytes("ISO-8859-1"), "utf-8");
            System.out.println(filename);
        }

        
        //2.从服务器中找到被下载资源的绝对路径
        String path = req.getServletContext().getRealPath("/WEB-INF/download/" + filename);
        System.out.println(path);
        // ----------------------------------------------------------------------------------------

        //2.1告诉浏览器不要直接打开文件,而是弹出下载框,保存文件
        resp.setContentType("application/x-msdownload");
        //2.2应该设置下载文件的建议保存名称

        //---------------------------------------------------------------------------------
        String useragent = req.getHeader("User-Agent");
        //下面两种方式谷歌浏览器全部都支持
        if (useragent.contains("MSIE")) {
            //filename = URLEncoder.encode(filename, "UTF-8");
            //System.out.println(filename);
            
            // IE浏览器的处理方式: 
            resp.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename, "UTF-8"));
            
            
        } else {
            //非IE浏览器的处理方式:
            //resp.setHeader("Content-Disposition", "attachment;filename="+(new String(filename.getBytes("utf-8"), "ISO-8859-1")));
            filename = new String(filename.getBytes("utf-8"), "ISO-8859-1");
            System.out.println(filename);
        }
        //---------------------------------------------------------------------------------

        // 3.磁盘文件-->程序中-->响应给用户
        Files.copy(Paths.get(path), resp.getOutputStream());
    }

}