日期:2014-05-16  浏览次数:20544 次

Ajax入门例子

index.jsp

<body>
  <form name="myform">
	<input value="test" type="button" onclick="test();" />
	<input value="text" name="datevalue" />
  </form>
  </body>
  <script>
  	//(1)获取对象实例
    var xmlHttp = GetXmlHttpObject();
	function test() {
		//(2)注意这里的url格式,<action path="/do/test"..的写法如下
		var url = "do/test.do";
		//(3)设定open参数
		xmlHttp.open("POST",url,true);
		//(4)设置状态改变时候的执行函数
		xmlHttp.onreadystatechange=setValue;
		xmlHttp.send(null);
	}

	function GetXmlHttpObject() {
		var xmlHttp = null;
		try {
			// Firefox, Opera 8.0+, Safari
			xmlHttp = new XMLHttpRequest();
		} catch (e) {
			// Internet Explorer
			try {
				xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
			} catch (e) {
				xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
			}
		}
		return xmlHttp;
	}
	
	function setValue()
	{
	    //(5)成功接收之后的处理
		if(xmlHttp.readyState == 4)
		{
			document.myform.datevalue.value=xmlHttp.responseText;
		}
	}
</script>

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struts_config.xml

  <action-mappings>
  	<action path="/do/test" type="com.test.TempAction"/>
  </action-mappings>

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TempAction.java

@Override
	public ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		PrintWriter pw = response.getWriter();
		SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
		String today = df.format(new Date());
		//(1)这里的print就是index.jsp中要获取的responseText
		pw.print(today);
		//(2)记得要flush
		pw.flush();
		//(3)如果是ajax的请求,这里不要返回页面,不然会将整个页面html源码赋值到responseText中
		return null;
	}
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