public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {response.setContentType("text/html");response.setContentType("text/xml;charset=utf-8");PrintWriter out = response.getWriter();//接收Flex端传来的参数String userName=request.getParameter("userName");String userPwd=request.getParameter("userPwd");String result="登录失败，用户名或密码错误！";if("admin".equals(userName) || "".equals(userPwd)){result="登录成功！";}//将登录信息返回给客户端
        out.println(result);out.flush();out.close();}

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark" xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600"initialize="init()"><fx:Script><![CDATA[import mx.controls.Alert;import mx.rpc.events.FaultEvent;import mx.rpc.events.ResultEvent;private function init():void{btn_login.addEventListener(MouseEvent.CLICK,login);//加载HTTPService的返回监听
                httpSer.addEventListener(ResultEvent.RESULT,httpSerResultHandler);httpSer.addEventListener(FaultEvent.FAULT,httpSerFaultHandler);}private function login(event:MouseEvent):void{httpSer.send();}//返回成功事件private function httpSerResultHandler(event:ResultEvent):void{Alert.show(event.result.toString(),"登录提示");}//返回失败事件private function httpSerFaultHandler(event:FaultEvent):void{Alert.show(event.fault.message as String,"登录提示");}]]></fx:Script><fx:Declarations><s:HTTPService id="httpSer" url="http://localhost:8090/FlexHttpService/FlexLoginServelt" method="POST"><s:request><!--需要发送到服务器的参数名，及值，接收参数名时必须一致--><userName>{txt_userName.text}</userName><userPwd>{txt_userPwd.text}</userPwd></s:request></s:HTTPService></fx:Declarations><s:Panel x="37" y="40" width="250" height="200"><s:Label x="37" y="28" text="用户名:"/><s:Label x="37" y="61" text="密    码:"/><s:TextInput id="txt_userName" x="82" y="24"/><s:TextInput id="txt_userPwd" x="83" y="56" displayAsPassword="true"/><s:Button x="83" y="115" label="登录" id="btn_login"/></s:Panel>
</s:Application>