jQuery-ajax-用户名异步请求

时间 2021-08-15 标签 javascript css html java mysql jquery ajax sql app jsp

文档说明：（基于jquery-mysql的ajax请求用户名是否存在）新手上路——记录点滴javascript

项目目录：css

wang.dbutil由高手封装的，借用html

总体项目，如连接过时，请关注留言，单独发送java

连接：https://pan.baidu.com/s/1x0lDCoTrHvIuPdpYXel4fg 密码：hlhmmysql

如下是jsp及servlet页面：jquery

<%@ page language="java" contentType="text/html; charset=utf-8"
	pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
<script
	src="http://cdn.static.runoob.com/libs/jquery/1.10.2/jquery.min.js"></script>
<script type="text/javascript">
	$(function() {
		var name = $("#username").val();
		$("#username").blur(function() {
			//alert(name);
			$.ajax({
				type : "post",
				url : "/ajaxpro1/LoginServlet",

				data : {
					username : $("#username").val(),
				//username:name
				},
				success : function(result) {
					if(result=="true"){$("#spid").css("display","block")}
					if(result=="false"){$("#spid").css("display","none")}

				},
				error : function() {
					alert("请刷新页面 ：）");
				}
			});
		});
	});
</script>
</head>
<body>
	<form action="#">
		user:<input type="text" id=username name="username" value="" /><span id="spid">已存在</span>
		 <input type="button" value="submit">
	</form>
	<style>
	    #spid{
	    display:none;
	    text_color=red;
	    }
	</style>
</body>
</html>

package wang.servlet;

import java.io.IOException;
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 wang.service.LoginService;

/**
 * Servlet implementation class LoginServlet
 */
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public LoginServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		//response.getWriter().append("Served at: ").append(request.getContextPath());
		String name = request.getParameter("username");
		System.out.println(name+"loginServlet接收的数据！！！！！！");
		LoginService loginService = new LoginService();
		try {
			boolean exist = loginService.getUserName(name);
			System.out.println(exist+"servlet返回的数据");
			//request.getSession().setAttribute("exit", exist);
			
			//request.setAttribute("result", exist);
			//request.getRequestDispatcher("/login.jsp").forward(request, response);
			
			String exist1 = new Boolean(exist).toString();
			System.out.println(exist1+"String型！！！！！！！111");
			response.getWriter().write(exist1);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}