109_JavaWeb_others

1  检查用户名

 protected void ajaxExistsUsername(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取请求的参数username
        String username = req.getParameter("username");
        // 调用userService.existsUsername();
        boolean existsUsername = userService.existsUsername(username);
        // 把返回的结果封装成为map对象
        Map<String,Object> resultMap = new HashMap<>();
        resultMap.put("existsUsername",existsUsername);

        Gson gson = new Gson();
        String json = gson.toJson(resultMap);

        resp.getWriter().write(json);
    }

	$(function () {

				$("#username").blur(function () {
					//1 获取用户名
					var username = this.value;
					$.getJSON("http://localhost:8080/book_limit/userServlet","action=ajaxExistsUsername&username=" + username,function (data) {
						if (data.existsUsername) {
							$("span.errorMsg").text("用户名已存在！");
						} else {
							$("span.errorMsg").text("用户名可用！");
						}
					});
				});

});

验证码

	// 给验证码的图片，绑定单击事件
				$("#code_img").click(function () {
					// 在事件响应的function函数中有一个this对象。这个this对象，是当前正在响应事件的dom对象
					// src属性表示验证码img标签的 图片路径。它可读，可写
					// alert(this.src);
					this.src = "${basePath}kaptcha.jpg?d=" + new Date();
				});

  <servlet>
        <servlet-name>KaptchaServlet</servlet-name>
        <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>KaptchaServlet</servlet-name>
        <url-pattern>/kaptcha.jpg</url-pattern>
    </servlet-mapping>

protected void regist(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取Session中的验证码
        String token = (String) req.getSession().getAttribute("KAPTCHA_SESSION_KEY");
        // 删除 Session中的验证码
        req.getSession().removeAttribute(KAPTCHA_SESSION_KEY);
        //  1、获取请求的参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        String email = req.getParameter("email");
        String code = req.getParameter("code");

        User user = WebUtils.copyParamToBean(req.getParameterMap(), new User());

//        2、检查 验证码是否正确  === 写死,要求验证码为:abcde
        if ( token != null && token.equalsIgnoreCase(code)) {
//        3、检查 用户名是否可用
            if (userService.existsUsername(username)) {
                System.out.println("用户名[" + username + "]已存在!");

                // 把回显信息，保存到Request域中
                req.setAttribute("msg", "用户名已存在！！");
                req.setAttribute("username", username);
                req.setAttribute("email", email);

//        跳回注册页面
                req.getRequestDispatcher("/pages/user/regist.jsp").forward(req, resp);
            } else {
                //      可用
//                调用Sservice保存到数据库
                userService.registUser(new User(null, username, password, email));
//
//        跳到注册成功页面 regist_success.jsp
                req.getRequestDispatcher("/pages/user/regist_success.jsp").forward(req, resp);
            }
        } else {
            // 把回显信息，保存到Request域中
            req.setAttribute("msg", "验证码错误！！");
            req.setAttribute("username", username);
            req.setAttribute("email", email);

            System.out.println("验证码[" + code + "]错误");
            req.getRequestDispatcher("/pages/user/regist.jsp").forward(req, resp);
        }