一个简单的AJAX

编程技术  /  houtizong 发布于 3年前   111

一个简单的AJAX

 

JS脚本：

 //页面调用方法function getInfo(obj){var ajax=getAjaxObject();url="ajaxAction.do?method=ajaxCheck";ajax.onreadystatechange =function(){var buffer="";if (ajax.readyState == 4&&ajax.status == 200){buffer=ajax.responseText;//*回调调用方法ajaxCallback(buffer);}}ajax.open("POST",url);ajax.setRequestHeader("Content-Type","application/x-www-form-urlencoded;charset=UTF-8");ajax.send("para="+obj);}//*get Ajax Objectfunction getAjaxObject(){if (window.ActiveXObject) {try{ajax = new ActiveXObject("Microsoft.XMLHTTP");}catch(e){alert("创建Microsoft.XMLHTTP对象失败,AJAX不能正常运行.请检查您的浏览器设置.");}} else {if (window.XMLHttpRequest) {try{ajax = new XMLHttpRequest();}catch(e){alert("创建XMLHttpRequest对象失败,AJAX不能正常运行.请检查您的浏览器设置.");}}}return ajax;}

 struts1.x action:

public ActionForward ajaxCheck(ActionMapping mapping, ActionForm form,HttpServletRequest request, HttpServletResponse response){ PrintWriter writer;response.setContentType("text/plain;charset=GBK");response.setHeader("Pragma","No-Cache");response.setHeader("Cache-Control","No-Cache");response.setDateHeader("Expires", 0);boolean enable=false;try{writer=response.getWriter();AjaxService ajax=new AjaxService ();String para=request.getParameter("para");enable = ajax.checkSomething(para);} catch (Exception e) {                                                log.error(e.getMessage());return mapping.findForward("exception");}writer.print(enable);writer.close();return null;}

 备注：

       如果需要向页面返回一个JS对象，可以在java中拼装一个对象字符串（{name:'jack',sex:'m'}），在前台得到这个字符串后将其转换成一个JS对象（var obj=null;  eval("obj="+outputString);  return obj;）。