AJAX实现注册验证用户名

本文实例为大家分享了AJAX实现注册验证用户名的具体代码,供大家参考,具体内容如下

功能说明

当用户在注册页面输入用户名并且鼠标焦点离开输入框时,到数据表中去验证该用户名是否已经存在,如果存在提示不可用,否则,提示可用。

接口

public interface UserDao {

public User findName(String name);

}

接口实现类

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

public class UserDaoImpl implements UserDao {

@Override

public User findName(String name) {

User user =null;

Connection conn = DBHelper.getConn();

String sql = "select * from user where name=?";

try {

PreparedStatement ps = conn.prepareStatement(sql);

ps.setString(1,name);

ResultSet rs = ps.executeQuery();

if (rs.next()){

user = new User();

user.setId(rs.getInt(1));

user.setName(rs.getString(2));

user.setPassword(rs.getString(3));

}

} catch (SQLException e) {

e.printStackTrace();

}

return user;

}

}

servlet

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet("/findName")

public class FindNameServlet extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

request.setCharacterEncoding("utf-8");

response.setContentType("text/html;charset=utf-8");

String name = request.getParameter("name");

UserDao userDao = new UserDaoImpl();

User name1 = userDao.findName(name);

if (name1!=null){

response.getWriter().write("1");

}else {

response.getWriter().write("2");

}

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

this.doPost(request, response);

}

}

JSP页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>

<head>

<title>AJAX实际操作注册验证用户名</title>

<script src="js/jquery-1.8.3.js"></script>

</head>

<body>

<form action="#" method="post">

<script type="text/javascript">

$(function () {

$("[name=userName]").blur(function () {

$.ajax({

type:"get",

url:"findName?name="+$("[name=userName]").val(),

dataType:"text",

success:function (data) {

//alert(data);

if (data=="1"){

$("#show").html("用户已存在!!!")

}else {

$("#show").html("用户名可用")

}

}

})

})

});

</script>

账号<input type="text" name="userName"><span id="show"></span></br>

密码<input type="password" name="password"></br>

<input type="submit" value="提交">

</form>

</body>

</html>

数据库如下:

运行结果如下:

以上是 AJAX实现注册验证用户名 的全部内容, 来源链接: utcz.com/z/357940.html

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