DownServlet
public class DownServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// request.setCharacterEncoding("utf-8");
// response.setContentType("text/html;charset=utf-8");
System.out.println("已经收到要下载的文件名称啦。。。。");
// 1 获取客户端请求下载的文件名称.
String filename = request.getParameter("filename");
// 解决GET方式请求的参数中文乱码问题:
filename = new String(filename.getBytes("ISO-8859-1"), "utf-8");
// 2 通过文件名称,查询数据表.
QueryRunner runner = new QueryRunner(JdbcUtils.getDataSource());
String sql = "SELECT * FROM filesave WHERE filename=?";
try {
FileSave filesave = runner.query(sql, new BeanHandler<FileSave>(FileSave.class), filename);
// 3 通过查询到的保存路径,读取具体文件.
InputStream in = new FileInputStream(new File(filesave.getSavepath()));
// 4 获取服务器端的响应输出流
OutputStream out = response.getOutputStream();
// 获取客户端请求头中的User-Agent
String userAgent = request.getHeader("User-Agent");
if (userAgent.contains("MSIE")) {
// IE浏览器
filename = URLEncoder.encode(filename, "utf-8");
filename = filename.replace("+", " ");
} else {
// 其他浏览器
BASE64Encoder base64Encoder = new BASE64Encoder();
filename = "=?utf-8?B?" + base64Encoder.encode(filename.getBytes("utf-8")) + "?=";
}
/*
* 通知浏览器:文件是需要下载的,而不是显示的. * 为下载设置ContentType和Content-Disposition
*/
response.setContentType(getServletContext().getMimeType(filename));
response.setHeader("Content-Disposition", "attachment;filename=" + filename);
// 5 利用IOUtils工具类的copy()方法
IOUtils.copy(in, out);
// 6 释放资源
in.close();
// out.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
download.jsp
a href="${pageContext.request.contextPath }/servlet/DownServlet?filename=黑臀.jpg">黑臀.jpg
a href="${pageContext.request.contextPath }/servlet/DownServlet?filename=哈哈.xls">2.xls
a href="${pageContext.request.contextPath }/servlet/DownServlet?filename=3.html">3.html
a href="${pageContext.request.contextPath }/servlet/DownServlet?filename=4.txt">4.txt
