MD5加密操作实例

/*添加用户*/
@RequestMapping(value = "/addUser.action", produces = "text/html;charset=UTF-8")
	public void addUser(HttpServletRequest req,HttpServletResponse resp) throws IOException, NoSuchAlgorithmException {
		String username = URLDecoder.decode(req.getParameter("username"), "UTF-8");
		String password = URLDecoder.decode(req.getParameter("password"), "UTF-8");
		String phonenum = URLDecoder.decode(req.getParameter("phonenum"), "UTF-8");
		String roleid = URLDecoder.decode(req.getParameter("roleid"), "UTF-8");
		Date day=new Date();  
		//利用MD5进行加密
		 MessageDigest md5=MessageDigest.getInstance("MD5");
		    BASE64Encoder base64en = new BASE64Encoder();
		    //加密后的字符串
		String passwordmd5=base64en.encode(md5.digest(password.getBytes("utf-8")));
		SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
		System.out.println(df.format(day));
		String createtime =df.format(day);
		resp.sendRedirect(req.getContextPath() + "/userinfo.jsp");
	}

/*用户登录*/
	@RequestMapping(value = "/login.action", produces = "text/html;charset=UTF-8")
	public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
		String username = URLDecoder.decode(req.getParameter("username"), "UTF-8");
		String password = URLDecoder.decode(req.getParameter("password"), "UTF-8");
		resp.setContentType("text/html; charset=UTF-8"); // 转码
		PrintWriter out = resp.getWriter();
		admin_userinfo user = userService.login(username);
		if (user == null) {
			out.flush();
			out.println("<script>");
			out.println("alert('此用户不存在');");
			out.println("history.back();");
			out.println("</script>");
			req.getRequestDispatcher(req.getContextPath() + "/login.jsp").forward(req, resp);
			return;
		}
		 MessageDigest md5 = null;
		try {
			md5 = MessageDigest.getInstance("MD5");
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
		    BASE64Encoder base64en = new BASE64Encoder();
		    //加密后的字符串
		String passwordmd5=base64en.encode(md5.digest(password.getBytes("utf-8")));
		
		if (!passwordmd5.equals(user.getPassword())) {
			out.flush();
			out.println("<script>");
			out.println("alert('用户名或密码不正确');");
			out.println("history.back();");
			out.println("</script>");
			return;
		}
		// >> 将User对象保存进session中
		req.getSession().setAttribute("user", user);
		Cookie autoLoginCookie = new Cookie("autoLogin",
				URLEncoder.encode(user.getUsername() + ":" + user.getPassword(), "utf-8"));
		autoLoginCookie.setPath(req.getContextPath() + "/");
		autoLoginCookie.setMaxAge(24 * 60 * 60);
		resp.addCookie(autoLoginCookie);
		resp.sendRedirect(req.getContextPath() + "/index.jsp");
	}