AJAX = 异步 JavaScript 和 XML。
AJAX 是一种用于创建快速动态网页的技术。
通过在后台与服务器进行少量数据交换，AJAX 可以使网页实现异步更新。这意味着可以在不重新加载整个网页的情况下，对网页的某部分进行更新。
传统的网页（不使用 AJAX）如果需要更新内容，必需重载整个网页面。
可使用jQuery的Ajax与Java通过POST方式进行交互
实现代码样例具体如下：
html代码
<body>
<div id="main">
<button id="myBut">Ajax获取数据</button>
<div id="container"></div>
</div>
</body>
style代码
<style type="text/css">
#main {
margin: 0 auto;
width: 400px;
}
#container {
width: 400px;
height: 300px;
border: 1px dashed #666;
text-align: center;
line-height: 300px;
}
</style>
javastript代码
<script type="text/javascript" src="js/jquery-1.8.3.js"></script>
<script type="text/javascript">
$(function() {
$('#myBut').click(function() {
$.post("JqueryAjaxServlet", {
age : 18,
name : "zhang"
}, function(data, textStatus) {
var container = $('#container');
var resultData = $.parseJSON(data);
var age = resultData.age;
var name = resultData.name;
container.html("name:" + name + "," + "age:" + age);
});
});
});
</script>
java代码
public class JqueryAjaxServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String age = request.getParameter("age");
String name = request.getParameter("name");
String personJSON = "{\"name" + "\":\"" + name + "\"," + "\"age"
+ "\":" + age + "}";
System.out.println(personJSON);
response.getWriter().write(personJSON);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
web.xml代码
<servlet>
<servlet-name>JqueryAjaxServlet</servlet-name>
<servlet-class>com.jquery.ajax.com.JqueryAjaxServlet</servlet-class>
</servlet> <servlet-mapping>
<servlet-name>JqueryAjaxServlet</servlet-name>
<url-pattern>/JqueryAjaxServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
另附其他实现代码：
ajax调用后台java类的例子 blog.****.net/rznice/article/details/43561645
java + jquery + ajax + json 交互 http://yangchunhe.iteye.com/blog/1751239