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:
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。