jQuery+Ajax authenticates users

This time I will bring you jQuery Ajax user verification. What are the precautions for jQuery Ajax user verification? The following is a practical case, let’s take a look.

nbsp;html>


<meta>
<title>Insert title here</title>
<script></script>
<script>
 //页面加载完成后
 $(function() {
  //添加失焦事件
  $("#username").blur(function() {
   //获取录入的用户名
   var usernamevalue = $("#username").val();
   //向服务器发送请求
   var url="/jquery_ajax/load";
   $("#username_span").load(url,{&#39;username&#39;:usernamevalue});
  });
 });
</script>


 <input><span></span>
 <br>
 <input>
 <br>

LoginServlet

public class LoadServlet extends HttpServlet {
 public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  // 解决乱码
  request.setCharacterEncoding("utf-8");
  response.setCharacterEncoding("utf-8");
  // 1.得到用户名
  String username = request.getParameter("username");
  // 2.判断用户名是否可以使用
  if ("tom".equals(username)) {
   // 用户名不可以使用
   response.getWriter().write("<font>用户名被占用</font>");
  } else {
   // 用户名可以使用
   response.getWriter().write("<font>用户名可以使用</font>");
  }
 }
 public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doGet(request, response);
 }
}

web.xml

<servlet>
 <description></description>
 <display-name>LoadServlet</display-name>
 <servlet-name>LoadServlet</servlet-name>
 <!-- 
  Class clazz = Class.forName("com.zxl.servlet.LoadServlet");
  Object obj = clazz.newInstatnce();
  // 反射去调用 doGet, doPost
  -->
 <servlet-class>com.zxl.servlet.LoadServlet</servlet-class>
 </servlet>
 <servlet-mapping>
 <servlet-name>LoadServlet</servlet-name>
 <url-pattern>/load</url-pattern>
 </servlet-mapping>

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the PHP Chinese website!

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