javascript实现ajax

标签：javascript   ajax   

关键步骤：

1 创建xmlHttpRequest对象；

2 添加回调函数；

3 创建链接；

4 设置请求头信息；

5 发送数据；

var xmlHttpRequest;
function chaj(){	
	if(f1.name.value==null||f1.name.value==""){
		alert("不能为空 ");
		return false;
	}
	if(window.XmlHttpRequest){
		xmlHttpRequest=new XmlHttpRequest();
	}else{
		xmlHttpRequest=new ActiveXObject("Microsoft.XMLHTTP");
	}
	
	xmlHttpRequest.onreadystatechange=callBack;
	var url="My";
	xmlHttpRequest.open("post",url,true);
	xmlHttpRequest.setRequestHeader("Content-type","application/x-www-form-urlencoded");
	xmlHttpRequest.send("name="+f1.name.value+"&timeStamp="+(new Date()).getTime());
	
}

function callBack(){
		
	if(xmlHttpRequest.readyState==4 && xmlHttpRequest.status==200){	
		var result=xmlHttpRequest.responseText;
		result=result.replace(/(^\s*)|(\s*$)/g, "");
		alert(result);
		//alert(result);
	}
}

服务器端：

通过PrintWriter回传信息；

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		response.setCharacterEncoding("utf-8");
		String name1=request.getParameter("name");
		String timeStamp1=request.getParameter("timeStamp");
		System.out.println(name1+timeStamp1);		
		PrintWriter out=response.getWriter();		
		out.print("成功");
		out.flush();
		out.close();
	}

javascript实现ajax

标签：javascript   ajax   

原文地址：http://blog.csdn.net/liangwenmail/article/details/47156831