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

  AJAX实际操作注册验证用户名       $(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")      }     }    })   })  });  账号
 密码

数据库如下：