Flex和servlet交互

??????Flex虽然提供了HTTPService，WEBService等方式与各种WEB服务器通信，但有时候我们仍然希望调用某些JAVA写的servlet或者JSP页面，这里举了个将FLEX页面数据导出为EXCEL表格的例子。

Flex代码：

?? protected function exportToExcel():void
???{
????var str:String ="<table><tr><td>aaa</td><td>aaa</td><td>aaa</td></tr></table>";
????var url:String = "/exportExcel.jsp";??? //这里替换为JSP访问路径
????var req:URLRequest = new URLRequest(url);
????var variables:URLVariables = new URLVariables();
????variables.htmltable = str;?
????req.data = variables; //Pass the variables
????req.method = URLRequestMethod.POST; //Don’t forget that we need to send as POST
????navigateToURL(u,"_self");
???}

????然后在页面添加一个BUTTON。点击后调用该function：

?? <mx:Button label="导出为EXCEL" click="exportToExcel()"/>

?

下面是JSP代码：

<%@ page language="java" import="java.util.*,java.io.*,java.net.URLDecoder" pageEncoding="utf-8"%>
<%@page contentType="application/msexcel;charset=utf-8"%>
<%
?request.setCharacterEncoding("utf-8");
?response.setHeader("Content-disposition","attachment;filename=exportExcel.xls");
?response.setContentType("application/msexcel");
?InputStream is = request.getInputStream();?
?BufferedReader tBufferedReader = new BufferedReader(new InputStreamReader(is));
?StringBuffer sb = new StringBuffer();
?String temp = new String("");
?while ((temp = tBufferedReader.readLine()) != null){
??sb.append(temp.replaceFirst("htmltable=",""));
?}
?out.print(URLDecoder.decode(sb.toString()));
%>

?

代码不多，但JSP页面有几个细节地方值得注意：

1.用request.getAttribute()或者request.getParameter()无法获得flex中传递的参数。

2.通过上面方式取得的数据为一个键值对字符串，本例为htmltable=<table><tr><td>aaa</td><td>aaa</td><td>aaa</td></tr></table>;

所以需要做下处理，去掉=和=前面的东西。

3.如果不进行URLDecoder.decode(sb.toString()),则得到的数据为%3Ctable......之类的数据，所以需要进行decode才能正确识别。

4.flex换行符为&#xa;