ajax简单实现

	var sno;
	sno = "周强";

	function show(sno){
		send("show.jsp?sno='"+sno+"'" );
	}
	
	var Http_request = false;
	
	function send(url){
		
		if(window.XMLHttpRequest){     //Mozilla 浏览器
			Http_request = new XMLHttpRequest();
			if(Http_request.overideMimeType){
				Http_request.overideMimeType("text/xml");
			}
		}
		else if(window.ActiveXObject){  //IE 浏览器
			try{
				Http_request = new ActiveXObject("Msxml2.XMLHTTP");
			}
			catch(e){
				Http_request = new ActiveXObject("Microsoft.XMLHTTP");
			}
		}
		
		if(!Http_request){ //异常, 创建对象实例失败
			alert("不能创建XMLHttpRequest对象实例");
			return false;
		}
		
		Http_request.onreadystatechange = returnRequest;
		Http_request.open("POST", url, true);
		Http_request.send(null);
	}
	
	function returnRequest(){
		 if (Http_request.readyState == 4) { // 判断对象状态
	            if (Http_request.status == 200) { // 信息已经成功返回，开始处理信息
				    var returnStr = Http_request.responseText;
				    alert(returnStr);
				    
	            } 
	            else { //页面不正常
	                alert("您所请求的页面有异常。");
	            }
	        }
	}
	
	show(sno);
  

在servlet设置 response.setContentType("text/html;charset=GBK");ajax 才能取得中文

在server.xml的

<Connector port="80" maxHttpHeaderSize="8192"
maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
enableLookups="false" redirectPort="8443" acceptCount="100"
connectionTimeout="20000" disableUploadTimeout="true" URIEncoding="GBK" /> 加上红色那段

ajax才能传中文到普通页面, 通过request.getParameter(name)取得.