最新下载
热门教程
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
AJAX实现注册验证用户名代码示例
时间:2021-03-13 编辑:袖梨 来源:一聚教程网
本篇文章小编给大家分享一下AJAX实现注册验证用户名代码示例,文章代码介绍的很详细,小编觉得挺不错的,现在分享给大家供大家参考,有需要的小伙伴们可以来看看。
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" %>AJAX实际操作注册验证用户名
数据库如下:
运行结果如下:
相关文章
- C#复制数组的两种方式及效率比较解读 10-24
- ASP.NET Identity用法解析 10-24
- ASP.NET MVC使用Identity增删改查用户介绍 10-24
- C语言中atoi函数模拟实现介绍 10-18
- .Net反向代理组件Yarp用法介绍 10-10
- .NET使用YARP通过编码方式配置域名转发实现反向代理教程 10-10