POI之下载模板（或各种文件）

该例基于Nutz框架

前台代码：

<a href="" id="errordownload"  onclick="downloadErrorLogsFile()"></a>

function downloadErrorLogsFile()
{$("errordownload").attr("href","${base}/platform/sys/user/downloaErrorLogsFile？filename="+filename);}

后台Controler层：

/**
 * 下载模版或其他文件等，
 */
@At
@Ok("void")
public class Download {
    //下载模版工具类
    public void downloadFile(@Param（fileName）String fileName，HttpServletRequest request,HttpServletResponse response) throws Exception {  

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

        BufferedInputStream in = null;  

        BufferedOutputStream out = null;
        request.setCharacterEncoding("UTF-8");
        String rootpath = request.getSession().getServletContext().getRealPath("/");
        try {
            File f = new File(rootpath + "uploadFile/" + fileName);
            response.setContentType("application/x-excel");
            response.setCharacterEncoding("UTF-8");
            response.setHeader("Content-Disposition", "attachment; filename="+new String(fileName.getBytes("gbk"),"iso-8859-1"));
            response.setHeader("Content-Length",String.valueOf(f.length()));
            in = new BufferedInputStream(new FileInputStream(f));
            out = new BufferedOutputStream(response.getOutputStream());
            byte[] data = new byte[1024];
            int len = 0;
            while (-1 != (len=in.read(data, 0, data.length))) {
                out.write(data, 0, len);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (in != null) {
                in.close();
            }
            if (out != null) {
                out.close();
            }
        }  

    }
}