Flex与Java通信之RemoteObject方式
在学习了flash中的事件机制后，我们就开始学习flex与Java中的3种通信方式。Flex与Java通信有3中方式：
●flex访问Java普通类使用RemoteObject方式，这也是用的最多的一种方式。
●flex访问Java服务器类（如servlet）用HttpService方式。
●Flex与WebService交互用WebService方式。
今天就先来学习flex访问普通Java类。在学习之前我们需要考虑这么一个问题：由于我们这3个例子都是以登陆为例子进行的，所以尽量让登陆界面分离出来可以重复使用，这用到Flex中的module。我们怎么将module中的数值传到父窗口去呢？我们又想到上节中学习的自定义事件。好了，既然想通了，就开始今天的学习。
将MyEclipse切换到MyEclipse视图，新建一个与flex交互的普通Java类，代码如下所示：
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package?com.it161.test;??public?class?RemoteObjectDemo?{????public?boolean?login(String?username,String?passworld?){??????????????if(username.equals("admin")&&passworld.equals("123")){???????????returntrue;???????}else{???????????returnfalse;???????}???????????}}在WebRoot/WEB-INF/flex目录下的remoting-config.xml文件中添加如下所示代码：
12345<destination?id="remoteObjectDemo">???????<properties>???????????<source>com.yqsn.test.RemoteObjectDemo</source>???????</properties>????</destination>将MyEclipse切换到Flash视图，首先自定义一个事件类LoginEvent.as，为以后传值服务，代码如下所示：
12345678910111213141516171819202122232425262728package?com.it161.ases{????import?flash.events.Event;????????public?class?LoginEvent?extends?Event????{?????????public?static?const?LOGIN_EVENT:String="LOGIN_EVENT";??????????????private??var?_loginMess:Object;??????????????public?function?LoginEvent(type:String,loginMess:Object=null,?bubbles:Boolean=false,cancelable:Boolean=false)???????{???????????this._loginMess=loginMess;???????????super(type,?bubbles,?cancelable);???????}??????????????public?functionget?loginMess():Object???????{???????????return?_loginMess;???????}?????????public?functionset?loginMess(value:Object):void???????{???????????_loginMess?=?value;???????}??????}}在这个类中我们定义了一个事件类型LOGIN_EVENT，定义了一个Object类型的变量，用于存值。
接着新建一个登陆信息的VO类LoginMess.as，为以后存贮用户信息服务，代码如下所示：
123456789101112131415161718192021222324252627282930313233343536package?com.it161.ases{????publicclass?LoginMess????{??????????????private??var?_username:String;??????????????privatevar?_passworld:String;??????????????publicfunction?LoginMess()???????{??????????????????}?????????publicfunctionget?passworld():String???????{???????????return?_passworld;???????}?????????publicfunctionset?passworld(value:String):void???????{???????????_passworld?=?value;???????}?????????publicfunctionget?username():String???????{???????????return?_username;???????}?????????publicfunctionset?username(value:String):void???????{???????????_username?=?value;???????}??????}}新建一个登陆界面，新建一个MXMLModule文件LoginModule.mxml，代码如下所示：
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364<?xmlversion="1.0"?encoding="utf-8"?><s:Module?xmlns:fx="http://ns.adobe.com/mxml/2009"?????????xmlns:s="library://ns.adobe.com/flex/spark"?????????xmlns:mx="library://ns.adobe.com/flex/mx"?width="256"?height="213">????????<fx:Script>???????<![CDATA[???????????import?com.flex.ases.LoginEvent;??????????????????????import?mx.controls.Alert;???????????import?mx.events.CloseEvent;???????????import?mx.managers.PopUpManager;??????????????????????protectedfunction?login_clickHandler(event:MouseEvent):void???????????{??????????????//?TODOAuto-generated?method?stub??????????????var?loginMess:Object=new?Object;??????????????loginMess.username=userName.text;??????????????loginMess.passworld=passworld.text;??????????????if(userName.text==""?||passworld.text==""){??????????????????Alert.show("用户名或密码不能为空！");??????????????????return;??????????????}??????????????this.dispatchEvent(newLoginEvent(LoginEvent.LOGIN_EVENT,loginMess));??????????????userName.text="";??????????????passworld.text="";??????????????PopUpManager.removePopUp(this);???????????}??????????????????????protectedfunction?loginTitleWindow_closeHandler(event:CloseEvent):void???????????{??????????????//?TODO?Auto-generatedmethod?stub??????????????userName.text="";??????????????passworld.text="";??????????????PopUpManager.removePopUp(this);???????????}??????????????????]]>????</fx:Script>????????<fx:Declarations>???????<!--?Place?non-visualelements?(e.g.,?services,?value?objects)?here?-->????</fx:Declarations>???????????????<s:TitleWindow?x="1"?y="1"?width="256"height="213"?title="登陆"id="loginTitleWindow"?close="loginTitleWindow_closeHandler(event)"?>?????????<s:Form?width="100%"?height="183"?>??????????????????????<s:FormItem?left="60"?height="39"?width="224"?label="用户名"?required="true"??>??????????????<s:TextInput?id="userName"?/>???????????</s:FormItem>??????????????????????<s:FormItem?required="true"?width="224"?label="密码"?>??????????????<s:TextInput?id="passworld"?displayAsPassword="true"?/>???????????</s:FormItem>??????????????????????????<s:FormItem?width="227">??????????????<s:Button?id="login"?label="登陆"?click="login_clickHandler(event)"/>???????????</s:FormItem>??????????????</s:Form>??????????????????</s:TitleWindow>?</s:Module>这个页面以后我们反复使用，这就是module文件的优点之一。在这个页面中我们不处理与Java交互的部分，因为既然是公共页面，我们应该将于Java交互的部分放在相应引用的文件中。
接着创建主页面RemoteObjectDemo.mxml，代码如下所示：
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768<?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"?width="100%"?height="100%">????????<fx:Script>???????<![CDATA[???????????import?com.flex.ases.LoginEvent;???????????import?com.flex.ases.LoginMess;???????????import?com.flex.component.LoginTitleWindow;???????????import?com.flex.module.LoginModule;??????????????????????import?mx.collections.ArrayCollection;???????????import?mx.controls.Alert;???????????import?mx.managers.PopUpManager;???????????import?mx.rpc.events.FaultEvent;???????????import?mx.rpc.events.ResultEvent;???????????[Bindable]???????????privatevar?loginMess:LoginMess=new?LoginMess();???????????privatevar?loginModule:LoginModule=new?LoginModule();???????????protectedfunction?login_clickHandler(event:MouseEvent):void???????????{??????????????PopUpManager.addPopUp(loginModule,this,true);??????????????PopUpManager.centerPopUp(loginModule);??????????????loginModule.addEventListener(LoginEvent.LOGIN_EVENT,getLoginMess);???????????}???????????publicfunction?getLoginMess(event:LoginEvent):void{??????????????var?username:String=event.loginMess['username'];??????????????var?passworld:String=event.loginMess['passworld'];??????????????loginMess.username=username;??????????????remoteObj.login(username,passworld);?????????????????????????}??????????????????????protectedfunction?remoteObj_resultHandler(event:ResultEvent):void???????????{??????????????//?TODOAuto-generated?method?stub??????????????var?str:Boolean=event.result?as?Boolean;??????????????if(str){??????????????????Alert.show(loginMess.username+",欢迎您回来...","提示");??????????????????aaa.text=loginMess.username+",欢迎归来...";??????????????????bbb.text="";??????????????????login.label="";??????????????}else{??????????????????Alert.show("登录失败，您输入的用户名或者密码不存在！","提示");??????????????}?????????????????????????}??????????????????????protectedfunction?remoteObj_faultHandler(event:FaultEvent):void???????????{??????????????//?TODOAuto-generated?method?stub??????????????Alert.show(event.fault.message,"出错了");???????????}??????????????????]]>????</fx:Script>????????<fx:Declarations>???????<!--?Place?non-visualelements?(e.g.,?services,?value?objects)?here?-->???????<s:RemoteObject?id="remoteObj"?destination="remoteObjectDemo"result="remoteObj_resultHandler(event)"fault="remoteObj_faultHandler(event)"?/>????</fx:Declarations>???????????<s:Label?x="219"?y="150"?width="182"?height="27"?fontSize="18"?id="aaa"?text="您还没有登陆，现在就"?verticalAlign="middle"/>???????<mx:LinkButton?x="409"??y="150"?width="57"??height="27"?label="登陆"?id="login"?fontSize="18"click="login_clickHandler(event)"/>???????<s:Label?x="478"?y="150"?width="37"?height="27"?id="bbb"?fontSize="18"?text="吧！"?verticalAlign="middle"/>???????</s:Application>好了，页面与类算是处理完了，打开服务器并部署项目，运行felx页面RemoteObjectDemo.mxml，如下所示：
? ? ? ? ? ? ? ? ? ? ? ? ? ?
当我们点击“登陆”按钮后，弹出module页面，如下所示：
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当我们输入的用户名和密码都正确时则提示你登陆正确：
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输入错误则提示你输入不正确：
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可以看出，我们输入的用户名与密码与Java中的login方法进行了交互。
好了，就学习这么多，下节将学习HttpService方式。
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