Flex3 HTTPService和Java使用json交互(登录示例)

Flex在做界面开发的时候有很多优势，Flex+java的组合也越来越流行，在整合开发的过程中自然会遇到数据交互的问题，下面介绍Flex3+Java整合使用json的情况。
一、Flex3中使用json需要corelib.swc   http://www.adobe.com/cfusion/exchange/index.cfm?view=sn111&extid=1078469
   将corelib.swc拷贝到Flex安装目录的sdks\3.0.0\frameworks\libs下
二、Java中进行数据处理得到json格式的数据,部分代码
Java代码
01./** 
02. * 浏览器直接返回信息 
03. *  
04. * @param content 内容 
05. * @param character 编码 
06. * @throws IOException 
07. */ 
08.protected void out(String content,String character) throws IOException {  
09.    HttpServletResponse response = ServletActionContext.getResponse();  
10.    response.setContentType("text/html;charset="+character);  
11.    PrintWriter out = response.getWriter();  
12.    out.print(content);  
13.    out.flush();  
14.    out.close();  
15.}  
16. 
17.    try{  
18.        Author author = authorService.getAuthorByName(username);  
19.        if( author==null ){  
20.            JSONObject json = new JSONObject();  
21.            json.put("status","0");  
22.            json.put("message","用户名不存在");  
23.            super.out(json.toString());  
24.        }  
25.        if(author.getPassword().equals(MD5.md5(password))){  
26.            session.put(Symbols.SESSION_AUTHOR, author);  
27.            JSONObject json = new JSONObject();  
28.            json.put("status","1");  
29.            json.put("message","登录成功");  
30.            super.out(json.toString());               
31.        }  
32.        else{  
33.            JSONObject json = new JSONObject();  
34.            json.put("status","0");  
35.            json.put("message","密码错误");  
36.            super.out(json.toString());       
37.        }  
39.    }  
40.    catch(ServiceException se){  
41.        JSONObject json = new JSONObject();  
42.        json.put("status","0");  
43.        json.put("message","登录失败");  
44.        super.out(json.toString());   
45.        throw new Exception(se);  
46.    } finally {  
47.    }         
48.    return NONE;  
三、Flex中请求URL得到json的数据，然后在script中解析json数据
XML/HTML代码
01.<?xml version="1.0" encoding="utf-8"?> 
02.<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"   
03.    horizontalAlign="center"   
04.    verticalAlign="middle"   
05.    verticalGap="15" 
06.    horizontalGap="15"> 
08.    <mx:Script> 
09.        <![CDATA[ 
10.            import mx.collections.ArrayCollection; 
11.            import mx.rpc.events.ResultEvent; 
12.            import com.adobe.serialization.json.JSON;  
13.            import mx.controls.Alert; 
14.             
15.            [Bindable] 
16.            private var photoFeed:ArrayCollection; 
17.
18.            private function doLogin():void { 
19.                trace("start send"); 
20.                var params:Object = new Object(); 
21.                params.username = username.text; 
22.                params.password = password.text; 
23.                loginCheck.send(params); 
24.                trace("end send"); 
25.            } 
26.
27.            private function doCancel():void { 
28.                username.text = ""; 
29.                password.text = ""; 
30.            } 
31.
32.            private function loginHandler(event:ResultEvent):void { 
33.                 
34.                var rawData:String = String(event.result); 
35.                 
36.                //decode the data to ActionScript using the JSON API 
37.                //in this case, the JSON data is a serialize Array of Objects. 
38.                var arr:Array = (JSON.decode(rawData) as Array); 
39.                var dataArray:ArrayCollection = new ArrayCollection(arr); 
40.                //arraySize = dataArray.length; 
41.                     
42.                // info.text = event.result.toString(); 
43.                var obj:Object = JSON.decode(rawData); 
44.            
45.                if(obj.status==1){ 
46.                     var request:URLRequest = new URLRequest(); 
47.                     request.method = URLRequestMethod.GET; 
48.                     request.url = "http://test.ntsky.com:8080/admin/posts.action"; 
49.                     // request. 
50.                     var loader:URLLoader = new URLLoader(); 
51.                     navigateToURL(request,"_self"); 
52.                } 
53.                else{ 
54.                    Alert.show(obj.message); 
55.                } 
56.            } 
57.             
58.         ]]> 
59.    </mx:Script>            
61.    <mx:HTTPService id="loginCheck" 
62.        url="http://test.ntsky.com:8080/admin/login.action" 
63.        resultFormat="text"            
65.        result="loginHandler(event)" /> 
67.    <mx:Panel x="330" y="192" width="290" height="177" layout="absolute" title="用户登录" fontSize="12" horizontalAlign="center" verticalAlign="middle"> 
68.        <mx:Form x="10" y="10" width="253" height="90"> 
69.            <mx:FormItem label="用户名:"> 
70.                <mx:TextInput id="username"/> 
71.            </mx:FormItem> 
72.            <mx:FormItem label="密  码 :"> 
73.                <mx:TextInput id="password" displayAsPassword="true"/> 
74.            </mx:FormItem> 
75.        </mx:Form> 
76.        <mx:Button x="65" y="103" label="登录" click="doLogin()"/> 
77.        <mx:Button x="144" y="103" label="取消" click="doCancel()"/> 
78.    </mx:Panel>       
80.</mx:Application>