Flex + Hessian + Spring

這是我第一偏的文章
我是初學 FLEX
如同標題所示我一直在找 FLEX 與 JAVA 溝通的管道
Hessian 我選擇了他，簡單易用且支持很多 client 當然最近也支持了 FLEX
要怎麼上手呢看了 Hessian 網站上的範例 hessian.caucho.com/doc/flash.xtp
有了一點基礎但是要實做一個 HessianServlet 總覺得不是很好用
想說我用 spring 用習慣了來看看有沒有解決的方法想到 spring 的文檔 Remoting and web services using Spring
static.springframework.org/spring/docs/2.5.x/reference/remoting.html
剛好有對 hessian 支持
所以馬上來試用 首先當然是設定一些文檔好讓 spring remoting 能夠活起來

web.xml 代码

< servlet >
    < servlet-name > remoting </ servlet-name >
    < servlet-class > org.springframework.web.servlet.DispatcherServlet </ servlet-class >
    < load-on-startup > 1 </ load-on-startup >
</ servlet >

< servlet-mapping >
    < servlet-name > remoting </ servlet-name >
    < url-pattern > /remoting/* </ url-pattern >
</ servlet-mapping >

上面的設置是必須的啦通過 servlet 的代理可直接呼叫你的 service
記住 servlet-name 與你下面檔案命名有關當然你也可以自己設定你喜歡對應的文檔名
我喜歡用 default 的值所以我的 servlet-name 為 remoting, spring 到時會去抓取
WEB-INF/remoting-servlet.xml 讀取你設定的 bean

xml 代码

< bean   id = "accountService"   class = "example.AccountServiceImpl" >
  < property   name = "accountDao"   ref = "accountDao" />
</ bean >

< bean   name = "/AccountService"   class = "org.springframework.remoting.caucho.HessianServiceExporter" >
  < property   name = "service"   ref = "accountService" />
  < property   name = "serviceInterface"   value = "example.AccountService" />
</ bean >

上面的 /AccountService 就是映射你要訪問的 url 當然你的 url 不是只 /AccountService 還要加上你 servlet-mapping 的 url-pattern /remoting/*
所以對應的 url 就是 /remoting/AccountService 這就是我們 flex 端要連上的位址
當然你也可以簡化你的 url-pattern 為 /* ,那 URL 就是只對應到 /AccountService
至於 flex 端要怎麼連上來呢 ？

xml 代码

< mx:Application
  xmlns:mx = "http://www.adobe.com/2006/mxml"   xmlns:word = "*"
  implements = "mx.rpc.IResponder" >

  < mx:Script >
    < [CDATA[
      import hessian.client.HessianService;

      import mx.rpc.AsyncToken;
      import mx.rpc.events.ResultEvent;

      private var service:HessianService  =  new  HessianService("remoting/AccountService");

      private function getAccount():void
      {
        var token:AsyncToken  =  service .getAccount.send(va.text);
        token.addResponder(this);
      }

      public function result(data:Object):void
      {
         var event : ResultEvent  =  data  as ResultEvent;
         uplogDataGrid.dataProvider  =  event .result as Array;
      }

      public function fault(info:Object):void
      {

      }
    ]]>
  </ mx:Script >
  < mx:TextInput   x = "100"   y = "90"   id = "va"   text = "" />
  < mx:Button   x = "260"   y = "90"   label = "Button"   click = "getAccount()"   />
  < mx:DataGrid   id = "aDataGrid"   x = "10"   y = "120"   width = "99%"   />
</ mx:Application >

其實很簡單只要使用 HessianService 去作遠程呼叫即可
先創造一個 HessianService 實例此實例當然要指向你要呼叫的遠端 sevice 的 url new  HessianService("remoting/AccountService"); 
然後用其 getOperation("getAccount").send();
以上面為例為 service.getOperation("getAccount").send(va.text);
也可以寫成
service.getAccount.send(va.text);
getAccount 當然是你要呼叫遠端 AccountService 的 getAccount( String name );

以下是一些 java

Account.java 代码

public   class  Account  implements  Serializable{
 private  String name;

 public  String getName();

 public   void  setName(String name) {
 this .name = name;
 }
}

AccountService. java 代码

public   interface  AccountService {

 public   void  insertAccount(Account account);

 public  List getAccounts(String name);
}

AccountServiceImpl. java 代码

public   class  AccountServiceImpl  implements  AccountService {

 private  AccountDao accountDao;

 private   void  setAccountDao(AccountDao) {
 this .accountDao = accountDao;
 }

 public   void  insertAccount(Account acc) {
 // do something...
 }

 public  List getAccounts(String name) {
 return accountDao.getAccounts(name);
 }
}

java 代码

// the implementation doing nothing at the moment
public   class  AccountDaoImpl  implements  AccountDao{

 public   void  insertAccount(Account acc) {
 // do something...
 }

 public  List getAccounts(String name) {
 List list = new  ArrayList();
 Account a = new  Account();
 a.setName(name);
 list.add(a);
 return  list;
 }
}