使用ajax验证用户名是否重复

发布时间：2020-12-16 03:25:41 所属栏目：百科来源：网络整理

导读：ajaxTest.jsp %@page contentType="text/html"%%@page pageEncoding="UTF-8"%!DOCTYPE htmlhtml head meta http-equiv="Content-Type" content="text/html; charset=UTF-8" titleJSP Page/title /head body 输入用户名：input type="text" /光标移除检查是否

ajaxTest.jsp

<%@page contentType="text/html"%>
<%@page pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
    	输入用户名：<input type="text" />光标移除检查是否重复
    	<hr />
    	<div>显示结果</div>
    	<script type="text/javascript">
    		document.getElementsByTagName("input")[0].onblur=function()
    		{
    			//alert("aaa");
    			//取得用户输入的用户名
    			var username=this.value;
    			//alert(username)
    			username=encodeURI(username);
    			var xhr=createXHR();
    			//准备以get方式发送请求
    			xhr.onreadystatechange=function()
    			{
    				if(xhr.readyState==4)
    				{
    					if(xhr.status==200)
    					{
    						var msg=xhr.responseText;
    						var divlele=document.getElementsByTagName("div")[0];
    						divlele.innerHTML=msg;
    					}
    				}
    			}
    			xhr.open("GET","servlet/getServlet?time="+new Date().getTime()+"&username="+username);
    			xhr.send(null);
    		}
    		function createXHR()
    		{
    			var xhr=null;
    			try{
    				xhr=new ActiveXObject("microsoft.xmlhttp");
    			}
    			catch(e)
    			{
    				try
    				{
    					xhr=new XMLHttpRequest();
    				}
    				catch(e)
    				{
    					window.alert("浏览器不支持");
    				}
    			}
    			return xhr;
    		}
    		
    	</script>
    	
 	</body>
</html>

Servlet控制：

package servlet;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class getServlet extends HttpServlet {

	public void doGet(HttpServletRequest request,HttpServletResponse response)
			throws ServletException,IOException {
		System.out.println("getservlet:doget");
		String username = request.getParameter("username");
		byte[] buf = username.getBytes("UTF-8");
		username = new String(buf,"UTF-8");
		String msg = null;
		if (username.equals("sa")) {
			msg = "<font color='red'>该用户已经存在</font>";

		} else {
			msg = "<font color='green'>可以注册</font>";
		}
		response.setContentType("text/html;charset=UTF-8");
		response.getWriter().write(msg);

	}

}

运行：

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!