Flex HttpService 方式与java交互（json数据类型）

mxml 代码：
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" applicationComplete="getData.send()">
<mx:Script>
<![CDATA[
import mx.rpc.events.ResultEvent;
import mx.controls.Alert;
import com.adobe.serialization.json.*;
[Bindable]
private var jsonObj:Object
internal function getUser(event:ResultEvent):void{
var re:String=event.result.toString();
jsonObj=JSON.decode(re);
}
]]>
</mx:Script>
<mx:HTTPService id="getData" url="http://localhost:8080/search/getusers" useProxy="false" result="getUser(event)" showBusyCursor="true"/>
<mx:Panel layout="absolute" left="10" top="10" bottom="10" right="10" title="用户记录表" fontSize="12">
<mx:DataGrid left="10" bottom="10" right="10" top="10" dataProvider="{jsonObj}">
<mx:columns>
<mx:DataGridColumn headerText="姓名" dataField="name" sortable="false" draggable="false"/>
<mx:DataGridColumn headerText="年龄" dataField="age" draggable="false"/>
<mx:DataGridColumn headerText="家庭住址" dataField="address" draggable="false"/>
<mx:DataGridColumn headerText="电子邮箱" dataField="email" draggable="false"/>
</mx:columns>
</mx:DataGrid>
</mx:Panel>
</mx:Application>

java代码

package mxr.flex;

import java.io.IOException;
import java.util.*;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.sf.json.JSONArray;

import mxr.flex.model.User;

public class DataSource extends HttpServlet{

@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String re=DataSource.getAllUsers();
resp.setCharacterEncoding("utf-8");
resp.getWriter().write(re);
System.out.println("aaaaaaaaaa");
//req.setAttribute("users", re);
}

public static void main(String[] args) {

}

public static String getAllUsers(){
String users="null";
List l=new ArrayList();
for(int i=0;i<15;i++){
User u=new User();
u.setName("user-->"+(i+1));
u.setAddress("中国.北京.海淀.上地"+(i+1)+"号");
u.setAge(18+i);
u.setEmail(i+1+"@digitalchina.com");
l.add(u);
}
JSONArray jsonList = JSONArray.fromObject(l);
users=jsonList.toString();
return users;
}

}