Ajax验证用户名是否存在博客分类： ajax ajaxservletJavaScript

程序员文章站 2024-03-18 16:30:58

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1.jsp代码

<%@ 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>

<title>Insert title here</title>

src="${pageContext.request.contextPath }/js/jquery-1.9.1.min.js"></script>

$(function() {

$(":input[name='name']").change(function() {

var val = $(this).val();

val = $.trim(val);

if (val != "") {

var url = "${pageContext.request.contextPath}/userName";

var args = {

"name" : val,

"time" : new Date()

};

$.post(url, args, function(data) {

$("#sj").html(data);

})

}

})

</script>

</head>

<body>

name:<input type="text" name="name" /> <br> <br>

</form>

</body>

</html>

2.servlet代码

package he.bdqn.ajax;

import java.io.IOException;

import java.util.Arrays;

import java.util.List;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

/**

* Servlet implementation class UserName

@WebServlet("/userName")

public class UserName extends HttpServlet {

private static final long serialVersionUID = 1L;

/**

* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse

* response)

protected void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

List<String> names = Arrays.asList("aa", "bb", "cc");

String name = request.getParameter("name");

String result = null;

if (names.contains(name)) {

result = "<font color='red'>用户名被使用</font>";

} else {

result = "<font color='green'>用户名可以使用</font>";

}

response.setContentType("text/html");

response.setCharacterEncoding("utf-8");

response.getWriter().print(result);

}

Ajax验证用户名是否存在博客分类： ajax ajaxservletJavaScript