java 导出mysql

java导出mysql备份
public String BackDBNow(HttpServletRequest request, String path, String username, String password) throws IOException {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String filename=System.currentTimeMillis()+".sql";
        if (username.equals("root") && password.equals("")) {
            File file = new File(path);
            boolean directory = file.isDirectory();
            boolean exists = file.exists();
            if (!directory || !exists) {
                request.setAttribute("message", "请输入正确的路径");
            } else {
                String sql = "cmd /c D:/mysql/mysql-5.5.46-winx64/bin/mysqldump   -h192.168.88.11 -u" + username + " -pPassw0rd! test > " + path + "/"+filename;
                Runtime.getRuntime().exec(sql);
            }
            request.setAttribute("message", "操作完成");
            return "redirect:BackDB?username=" + username + "&password=" + password + "&path=" + path;
        } else {
            request.setAttribute("message", "用户名密码错误");
        }
        return "redirect:BackDB?username=" + username + "&password=" + password + "&path=" + path;
    }