Flex json ArrayCollection 相关

<?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" creationComplete="init(event)">
	<s:layout>
		<s:BasicLayout/>
	</s:layout>
	<fx:Script>
		<![CDATA[
			import com.adobe.serialization.json.JSON;
			
			import mx.collections.ArrayCollection;
			import mx.controls.Alert;
			import mx.events.FlexEvent;
			import mx.rpc.events.ResultEvent;
			
			import spark.events.IndexChangeEvent;

			private var proColl:ArrayCollection;
			private var cityColl:ArrayCollection;
			protected function init(event:FlexEvent):void
			{
				flexutil.getProvince();
			}


			protected function flexutil_resultHandler(event:ResultEvent):void
			{
				var jsonPro:String = event.result as String;
				var proArr:Array = (JSON.decode(jsonPro) as Array); 
				proColl = new ArrayCollection(proArr);
				province.dataProvider = proColl;
				//province.selectedIndex = 0;
			}


			protected function province_changeHandler(event:IndexChangeEvent):void
			{
				var code : int = province.selectedItem.code as int;
				cityUtil.getCity(code);
			}


			protected function cityUtil_resultHandler(event:ResultEvent):void
			{
				var jsonCity : String = event.result as String;
				var cityArr:Array = (JSON.decode(jsonCity) as Array);
				cityColl = new ArrayCollection(cityArr);
				city.dataProvider = cityColl;
				//city.selectedIndex = 0;
			}

		]]>
	</fx:Script>
	<fx:Declarations>
		<mx:RemoteObject id = "flexutil" destination="FlexUtil"  endpoint="/MyFlexApp/messagebroker/amf" result="flexutil_resultHandler(event)">
		</mx:RemoteObject>
		<mx:RemoteObject id = "cityUtil" destination="FlexUtil"  endpoint="/MyFlexApp/messagebroker/amf" result="cityUtil_resultHandler(event)">
		</mx:RemoteObject>
	</fx:Declarations>
	<s:DropDownList x="169" y="78" width="175" id="province" labelField="name" changing="province_changeHandler(event)"></s:DropDownList>
	<s:DropDownList x="507" y="78" width="175" id="city" labelField="name"></s:DropDownList>
	<s:Label x="65" y="78" text="一级城市" width="83" height="21" fontSize="18"/>
	<s:Label x="403" y="78" text="二级城市" width="83" height="21" fontSize="18"/>
</s:Application>

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.google.gson.Gson;
import com.jite.entity.OrgData;

public class FlexUtil {
	private Gson gson = new Gson();
	public String getProvince() {
		String jsonString = gson.toJson(proList);
		return jsonString;
	}

	public String getCity(Integer code) {
		List cityList = (List) proMap.get(code);
		String jsonString = gson.toJson(cityList);
		return jsonString;
	}

	private Map proMap = new HashMap();
	private List proList = new ArrayList();

	public FlexUtil() {
		OrgData pro1 = new OrgData(1, "湖南");
		OrgData pro2 = new OrgData(2, "湖北");
		OrgData pro3 = new OrgData(3, "江苏");

		proList.add(pro1);
		proList.add(pro2);
		proList.add(pro3);

		OrgData city1 = new OrgData(1, "长沙");
		OrgData city2 = new OrgData(2, "邵阳");
		OrgData city3 = new OrgData(3, "常德");
		OrgData city4 = new OrgData(4, "武汉");
		OrgData city5 = new OrgData(5, "华容");
		OrgData city6 = new OrgData(6, "南京");
		OrgData city7 = new OrgData(7, "无锡");

		List list1 = new ArrayList();
		list1.add(city1);
		list1.add(city2);
		list1.add(city3);

		List list2 = new ArrayList();
		list2.add(city4);
		list2.add(city5);

		List list3 = new ArrayList();
		list3.add(city6);
		list3.add(city7);

		proMap.put(pro1.getCode(), list1);
		proMap.put(pro2.getCode(), list2);
		proMap.put(pro3.getCode(), list3);
	}
}