假设：
1、你的页面在Web-Root下，内容为： <div id="showMsg"></div><input type="text" id="userName" />，所用编码为utf-8
2、你的servlet为： HelloWorldServlet.java 映射路径为 servlet/helloWorldServlet
步骤：
1、引入jquery-1.6.4.min.js
2、编写id为userName的输入框的点击触发函数：
$("#userName").keyup(function(){
$.ajax({
type: "post",
url: "servlet/helloWorldServlet?userName="+$(this).val(),
dataType: "json",
success: function(data){
$("#showMsg").html(data.msg);//修改id为showMsg标签的html
}, error: function(){
alert("请求出错");
}
})
})
3、后台处理接收到的内容：
request.setCharactorEncoding("utf-8");
String userName = request.getParameter("userName");
response.setCharactorEncoding("utf-8");
PringWriter out = response.getWriter();
out.print("{\"msg\":\"你好~~"+userName+"!\"}");
注意事项：
1、这里的编码统一为utf-8
2、请求路径servlet/helloWorldServlet为相对路径，因此你的页面必须在项目的Web-Root下（也就是默认的web文件夹下，名字可能因项目配置不同而改变）
网上的 Jquery ajax Demo 大多都是基于php
很少 有java的 今天就把自己的Demo贴出来 和大家共同学习
现在就 Jquery ajax 的 $.ajax(),$.post(),$.get();
首先是 服务端的Servlet 演示这三个函数的用法对都是用的同一个 服务端
package com.june.servlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
public class jqueryAjaxServer extends HttpServlet {
public jqueryAjaxServer(){
super();
}
public void doGet(HttpServletRequest request,HttpServletResponse response)
throws IOException ,ServletException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out=response.getWriter();
String account=request.getParameter("account");
if("iamcrzay".equals(account)){
out.print("Sorry,the user is exist");
}
else{
out.print("Congratulation,this accont you can use!!!!");
}
out.close();
}
public void doPost(HttpServletRequest request,HttpServletResponse response)
throws IOException ,ServletException {
this.doGet(request, response);
}
}
下面是WEB.XML
Xml代码
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
<servlet-name>jqueryAjaxServer</servlet-name>
<servlet-class>com.june.servlet.jqueryAjaxServer</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>jqueryAjaxServer</servlet-name>
<url-pattern>/jqueryAjax</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
<servlet-name>jqueryAjaxServer</servlet-name>
<servlet-class>com.june.servlet.jqueryAjaxServer</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>jqueryAjaxServer</servlet-name>
<url-pattern>/jqueryAjax</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
下面是Jsp页面
第一个是 jqueryAjax.jsp 本页使用的是$.ajax()
Html代码
<%@ page language="java" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>jquery ajax</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<script src="js/jquery-1.2.6.js" type="text/javascript"></script>
<script language="javascript">
$(function(){
$('.sumbit').click(function(){
if($('#account').val().length==0){
$('.hint').text("用户名不能位空").css({"background-color":"green"});
}
else{
$.ajax({
url:'jqueryAjax',
data:{account:$('#account').val()},
error:function(){
alert("error occured!!!");
},
success:function(data){
$('body').append("<div>"+data+"</div>").css("color","red");
}
});}
});
});
</script>
</head>
<body>
<h3 align="center">jquery AjaX</h3>
<hr>
<label>请输入用户名 ：</label>
<input id="account" name="account" type="text">
<input class="sumbit" type="button" value="检测">
<div class="hint">
</div>
</body>
</html>
<%@ page language="java" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>jquery ajax</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<script src="js/jquery-1.2.6.js" type="text/javascript"></script>
<script language="javascript">
$(function(){
$('.sumbit').click(function(){
if($('#account').val().length==0){
$('.hint').text("用户名不能位空").css({"background-color":"green"});
}
else{
$.ajax({
url:'jqueryAjax',
data:{account:$('#account').val()},
error:function(){
alert("error occured!!!");
},
success:function(data){
$('body').append("<div>"+data+"</div>").css("color","red");
}
});}
});
});
</script>
</head>
<body>
<h3 align="center">jquery AjaX</h3>
<hr>
<label>请输入用户名 ：</label>
<input id="account" name="account" type="text">
<input class="sumbit" type="button" value="检测">
<div class="hint">
</div>
</body>
</html>
第二个用的是 $.post()
Html代码
<%@ page language="java" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>jquery ajax</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<script src="js/jquery-1.2.6.js" type="text/javascript"></script>
<script language="javascript">
$(function(){
$('.sumbit').click(
function(){
if($('#account').val().length==0){
$('.hint').text("The account is cant't be null").css({"color":"red","background-color":"yellow"});
}
else{
$.post("jqueryAjax","account="+$('#account').val(),function(data){
$('.hint').text(data).css({"color":"red","background-color":"yellow"});
})
}
});
});
</script>
</head>
<body>
<h3 align="center">jquery Ajax</h3>
<hr>
<label>请输入用户名 ：</label>
<input id="account" name="account" type="text">
<input class="sumbit" type="button" value="检测">
<div class="hint">
</div>
</body>
</html>
<%@ page language="java" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>jquery ajax</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<script src="js/jquery-1.2.6.js" type="text/javascript"></script>
<script language="javascript">
$(function(){
$('.sumbit').click(
function(){
if($('#account').val().length==0){
$('.hint').text("The account is cant't be null").css({"color":"red","background-color":"yellow"});
}
else{
$.post("jqueryAjax","account="+$('#account').val(),function(data){
$('.hint').text(data).css({"color":"red","background-color":"yellow"});
})
}
});
});
</script>
</head>
<body>
<h3 align="center">jquery Ajax</h3>
<hr>
<label>请输入用户名 ：</label>
<input id="account" name="account" type="text">
<input class="sumbit" type="button" value="检测">
<div class="hint">
</div>
</body>
</html>
第三个是用的$.get()
Html代码
<%@ page pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>jquery get</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<script src="js/jquery-1.2.6.js" type="text/javascript"></script>
<script type="text/javascript">
$(function(){
$('.sumbit').click(function(){
if($('#account').val().length==0){
$('.hint').html("用户名不能位空！！！").css({"color":"#ffoo11","background":"blue"});
}
else{
$.get("jqueryAjax","account="+$('#account').val(),
function(data){
$('.hint').html(data).css({"color":"#ffoo11","background":"green"});
});
}
});
});
</script>
</head>
<body>
<h3 align="center">jquery AjaX</h3>
<hr>
<label>请输入用户名 ：</label>
<input id="account" name="account" type="text">
<input class="sumbit" type="button" value="检测">
<div class="hint">
</div>
</body>
</html>
<%@ page pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>jquery get</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<script src="js/jquery-1.2.6.js" type="text/javascript"></script>
<script type="text/javascript">
$(function(){
$('.sumbit').click(function(){
if($('#account').val().length==0){
$('.hint').html("用户名不能位空！！！").css({"color":"#ffoo11","background":"blue"});
}
else{
$.get("jqueryAjax","account="+$('#account').val(),
function(data){
$('.hint').html(data).css({"color":"#ffoo11","background":"green"});
});
}
});
});
</script>
</head>
<body>
<h3 align="center">jquery AjaX</h3>
<hr>
<label>请输入用户名 ：</label>
<input id="account" name="account" type="text">
<input class="sumbit" type="button" value="检测">
<div class="hint">
</div>
</body>
</html>
http://iamcrzay.iteye.com/blog/237940