Flex使用JSON格式与Java通信

在使用Flex,Java，Json更新Mysql数据【高级篇】 中我记得Flex界面中数据是使用一个JsonArray封装了JsonObject之后传给Java后台的。可是今天发现，如果你的数据只有一个JsonObject，那么是否直接传JsonObject也可以呢？试试看：

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="" layout="absolute" creationComplete="initApp()">
<mx:Script>
    <![CDATA[
        import mx.rpc.events.ResultEvent;
        import mx.collections.ArrayCollection;
        import com.adobe.serialization.json.JSON;
        [Bindable]
        private var stuMarkDataArray:ArrayCollection;
        
        private function initApp():void{
            stuMarkDataArray = new ArrayCollection();
        }
        public function sendStuInfo():void{
            var stuFaculty:String = facultyxt.text;
            var stuMajor:String = majortxt.text;
            var stuInfo:Object = new Object;
            stuInfo.faculty = stuFaculty;
            stuInfo.major = stuMajor;
            var stuStr:String = JSON.encode(stuInfo);
            sendInfo.getStuMarks(stuStr);
        }
        public function showStuMark(event:ResultEvent):void{
            note.text = "Success....";
            var rawArray:Array;
            var rawData:String = event.result as String;
            rawArray = JSON.decode(rawData) as Array;
            stuMarkDataArray = new ArrayCollection(rawArray);
        }
        public function getTotalMarks():void
        {
            getTotal.getTotalMarks();
            note.text="I am searching...";
        }
        public function showTotalMark(event:ResultEvent):void{
            note.text = event.result as String;
    
        }
    ]]>
</mx:Script>
<mx:RemoteObject id="sendInfo" destination="getStuMark" showBusyCursor="true" result="showStuMark(event)"/>
<mx:RemoteObject id="getTotal" destination="getTotalMark" showBusyCursor="true" result="showTotalMark(event)"/>
    <mx:Panel x="39" y="31" width="346" height="301" layout="absolute">
        <mx:Label x="27" y="25" text="Faculty"/>
        <mx:TextInput x="72" y="23" id="facultyxt"/>
        <mx:TextInput x="72" y="64" id="majortxt"/>
        <mx:Label x="27" y="66" text="Major"/>
        <mx:Button x="27" y="92" label="各科成绩" width="109" click="sendStuInfo()"/>
        <mx:DataGrid x="10" y="140" height="79" width="304" dataProvider="{stuMarkDataArray}">
            <mx:columns>
                <mx:DataGridColumn headerText="Math" dataField="math"/>
                <mx:DataGridColumn headerText="Chinese" dataField="chn"/>
                <mx:DataGridColumn headerText="English" dataField="eng"/>
            </mx:columns>
        </mx:DataGrid>
        <mx:Label x="10" y="227" width="304" id="note" height="24"/>
        <mx:Button x="192" y="94" label="总成绩" click="getTotalMarks()"/>
    </mx:Panel>
    
</mx:Application>


 后台JSonTestJava.java

package test;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
public class JsonTestJava {
  public String getStuMarks(String info){
     String result = new String();
     JSONObject jsonObject = JSONObject.fromObject(info);
     String faculty = jsonObject.getString("faculty");
     String major = jsonObject.getString("major");
    
     JSONArray stuMarksArray = new JSONArray();
    
     if(faculty.equals("IT") && major.equals("SE")){
        for(int i=0;i<3;i++){
            JSONObject stuObj = new JSONObject();
            stuObj.put("math", 100-i*2);
            stuObj.put("eng", 80+2*i);
            stuObj.put("chn", 90-i);
            stuMarksArray.add(stuObj);
        }
     }
     result = stuMarksArray.toString();
     return result;
  }
  public String getTotalMarks(){
     JSONObject stuObj = new JSONObject();
     stuObj.put("name", "leyond");
     stuObj.put("mark","344");
     return stuObj.toString();
  }
}


 使用的方法跟JSONArray差不多，只不过使用JsonArray的时候，需要先把每个jsonObject解析出来。所以比较方便的。但是 现在有一个问题，如果你在后台传给的前台Flex中的是一个JSONObject的数据，请问如何在前台解析出来的。就是这里的代码该如何写呢：

public function showTotalMark(event:ResultEvent):void{
            var marks:Object= JSON.decode(event.result as String);
            note.text = marks.name + marks.mark;
        }

这样就可以了，marks.name 和marks.mark就可以分别解析出name和mark。是不是很方便呢。当然如果你的数据很多，就需要用到JSAONArray了。这里就不多讲了。这个是这个例子的效果实例：