AJAX实现注册验证用户名
AJAX实现注册验证用户名
这篇文章主要为大家详细介绍了AJAX实现注册验证用户名,文中示例代码介绍的非常详细,具有一定的参考价值,感兴趣的小伙伴们可以参考一下
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
1 2 3 | public interface UserDao { public User findName(String name); } |
接口实现类
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 | 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
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | 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
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | <%@ 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:
以上就是本文的全部内容,希望对大家的学习有所帮助
原文链接:https://blog.csdn.net/qq_43928469/article/details/114372890