Cloud computing
Not really a Java subject but it attract people. We tried to define the cloud computing and we fixed that there is 3 offers :

• IAAS (Infrastructure as a Service): this is typical Amazon services products, S3 for storage and EC2 for virtualized servers. Amazon offer very basic service now with a very powerful management tool in Eclipse plug-in (see the demo). There is also Elastic Grid proposing to develop and deploy easily on the Amazon infrastructure, GoGrid an Amazon concurrent. I believe that the recent IBM / Sun merge will create new offerings.
• SAAS (Software as a Service): we find a lot of solutions (often based on the previous offer), for example Amazon SimpleDB, Amazon SQS, Google Apps, Microsoft Azure Services CloudMQ, ZumoDrive … and I could continue like a long time…
• PAAS (Platform as a Service): is hosting the application on a common and scalable platform, it is typically Google AppEngine, it is possible to deploy all yours web application if you know Python. Microsoft probably has a deal in Azure (I should have a look) and Sun has just launched Zembly.

A lot of discussion on what about offline, security, and where is java in the cloud. For me offline mode is really important in a world of increasingly nomad people. Cloud is primarily storage space allowing me to share my data between my devices, then an area of services, and finally deployment platform of my apps.
Finished managing a backup that is never done, losed time finding  a way to share data and finally used USB key, now my data are in the cloud and synchronized on all my devices. I have set up Zumodrive in my company and it’s very cool, the documents are shared even outside the company and I don’t care about backup.
Security is the most bigger difficulty for acceptance in the company, I hear the same remarks when talking about the payment on Internet ten years ago. All these services are secure and there is no zero risk.
Java have his place in the cloud on client and server side. The multi platform aspect facilitates the developments on the client (eg: ZumoDrive client is in Java), I want to see more and more Java APIs “cloud-ready” facilitating the integration of service in code. Similarly on the server side I look forward to Google AppEngine in Java.
Finally the advantage of cloud computing is primarily economic, smalls company are the first customers and have found lower cost and flexible capabilities.

DDD (Domain Driven Design)
I had little success at the last barcamp with this subject, this time it was proposed by others much more stronger than me and have made relevant arguments on the benefits of the concept. One of the important point raised we used talking too much technical and framework implementation than focus more on the reality, something that we tend to forget wanting to put our new framework in our code. I talked about Qi4j, that is not pure DDD implementation, but is for me the best way to modelling reality. I want make a demo of my medical record implemented with Qi4j to really prove that this approach is relevant.
Of course I’m convinced that a DDD refactoring of an existing code is difficult. DDD is a best practice and a new way of development vision. Have to follow for sure …

Thank you again to the organizers. It is always a good opportunity to exchange. And i hope Google will open their doors as often as possible;)

Migration

Steps of migration that I present here are dedicated to those who have a Thunderbird client.

• If you use Thunderbird, and you have the directories:
  • for those use IMAP : click on the bulb at the bottom right, it will put you offline and recover all local directories. Be carrefful you should declared as Synchronized for offline use in Account settings in the  Offline and Disk Space and click on Select folders for offline use then select the folders you want to recover.
  • download the migration tool, install and run it
  • select the folders to migrate, initially it is empty, a link on the right “add Thunderbird directory” allows you to select folders, navigate to your Thunderbird home directory:
    • For XP: C: / Documents and Settings / <user> / Application Data / Thunderbird / Profiles / …
    • For Vista: C: / Users / <user> / AppData / Roaming / Thunderbird / Profiles / …
    • POP in: … / mail
    • IMAP in: … / ImapMail
  • select the files to the directory name that you want to recover (NB: not those of the same name with the .msf extension). Normally not need to get the subdirectories, these will be automatically detected, no need either to retrieve the trash and spam. Please note it may take time, the tool used to evaluate the loading time, you can perform this operation several times, the tool remembers the place where you left off.
• If you use Thunderbird or webmail and you have no folders, there’s nothing to do special for migration. If you using webmail and you have online directories it’s more complex, the only way I found is to install Thunderbird to retrieve all your data over IMAP and apply first step

Note: Even if GMail offers retrieve mail from another account (see paragraph below), this system uses POP and therefore does not recover the tree.

Before switching to GMail, until everyone has made her migration, it is possible to redirect his mail to GMail, go to Settings (top right), then go into Accounts and click on Add a mail account
WARNING for those IMAP: POP will retrieve all the messages you’ve already recovered in first step, you need to empty your inbox and destroy all the directories.

To reconfigure Thunderbird with GMail account here are some tips that will help you save time.

• GMail provides assistance to configure your account.
• To manage the offline, go to “Account Settings” menu “Offline and disk space” and check the boxes and select the directory, so you can also access your mails on the train via Thunderbird
• The plugin indispensable Nostalgy: keyboard shortcut to sort your mails
• Other:
• Lightning calendar (synced with google calendar), this plugin is good but can quickly become problematic if you share too much time because the requests update to Google Calendar slow sometimes use Thunderbird
• Google Contact or Zindus : sync of contact

Setting up your mobile phone

Go to http://mobile.google.fr/ from your mobile, it works with all smartphones that can go on the Web and it’s very useful

Mailing lists

For mailing lists, standard version’s GoogleApps features are very limited, the distribution list is simply a contact group. There is no rights management and even external users can send e-mails on this list. For this you must upgrade to premium version where you have groups management. You can also not store this list in a common area but there is a trick with google-groups: for this you must create a group that simply archive your mailling list and will be accessible on the Web, simply by adding a special receiver to your distribution list.

Limitations

Note to manage spam, GMail limit the sending of mail per user per day. This it is not possible to use a GMail account to send notifications for an application.

Options

To take advantage of other features on GMail (transform mail document multiple inbox …) know that when you set your GMail in your language you  neither acces to the tab “Labs” containing all these options. You must switch to “English U.S.” to make this selection appear and then come back in your language.

Conclusion

Very positive! Although migration has been slow because the migration tool is not simple to use, the concept of directory disappears in the Gmail web interface and makes use of labels, some mails were lost. Few people are complaining and everyone saw the benefits of a collaboration tool that works. Some use the web interface, it is true, is very well thought out and offers the same benefits that a classic mail client (especially since the offline mode). In the end we do not regret this first step in the cloud that we save time and money.

• KapInspect

KapInspect is the flex equivalent of the famous Firebug console. Activated on a simple click it allows to inspect all the flex components of the page, to show and to modify their properties.

• Cairngorm console et purMVC console
  

Those consoles allow to show at runtime the various components of the framework.

The integration is quite simple. After setting the .swc component in the project classpath, you just have to add the good tag in your mxml file.

For example :

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical" xmlns:kapit="fr.kapit.*"> ... <kapit:KapInspect/> </mx:Application>

Then to open the console just make a Ctrl+Alt+Click in the flash stage. Notice that you can use the various consoles simultaneously
For pureMVC console you have to change your Facade class to extend DebugFacade. You’ll find explanationhere

• Spring integration : Version 1.0 have been released, this framework is the implementation of the design pattern book EAI Pattern.
• JitterBit : an open source EAI with advanced management tool, the GUI is attractive but I have not had time yet to really test the product
• OpenAdaptor : First opensource EAI developed by a german team. I personally used to develop an EAI dedicated to health which actually interconnects the SAMU of the Champagne-Ardennes region (3 to 4 messages per minute it’s still reasonable). The product is stable and multi-source design, pipe, sink is well thought out. There is a lot of connectors but not always reusable, it is better to re-develop your own when you have specific features. I used the original version 1.7.2, there was no version 2 but a complete refactoring that is now version 3. An article by the author was published recently in JDJ.
• Mule : a lightweight ESB now well known, I have not had the opportunity to implement it, but before the arrival of Spring Integration it was one that interested me most. Nicolas has implemented it and has even made a quickie at DEVOXX08.
• OpenESB : implementation of the Sun JBI specification (JSR-208) dedicated to integration
• JBoss ESB : ESB by JBoss
• Apache Synapse : lightweight ESB of Apache Foundation
• Apache serviceMix : ESB, JBI implementation
• Apache CAMEL : implementation of EAI pattern (idem Spring integration)
• Apache CXF : implementation of JAX-WS.
• Axis2 : same but with asynchronous mode and REST. I started working on web services with version 1 of this framework and realize practical training works with it. The architecture allows flexible configuration based on a chain between the request and response. It is simple to use to make an ETL. Version 2 provides asynchronous, more performance and AXIOM to manage attachments (easier to use than SwA)
• APMQ : the new specification to standarize messaging tools (initiated by JBoss), it is only the beginning but we have to follow
• ActiveMQ : the open source open source MQ, Julien Dubois has some experience on the subject and tells us that we must be wary of some bugged versions (5.0 for example). The tool is not mature and often encounter problems because developers believe they can integrate easily in their application. Apparently this is not as simple as a single jar to add.
• OpenMQ : the Sun open source MQ, I could follow the session at the DEVOXX08, it was very broad but Sun show that the project is well supported and adopted by their clients. If I switch to open source (currently i use WebSphere MQ) i think i choose this one.
• WebSphere MQ : the historical MQ from IBM that I use now. Robust, mature but hard to configure. Even if IBM provide RCP application for configuration it remains complex. I added the MQ Everyplace module to deploy on mobile handsets, configuration is even more complex. Once it is ready it works well.

Thanks to Luc Bizeul who organize this event and also for the cocktail at the end. I’m waiting for the next

package { public class Singleton { private static var _instance:Singleton; public function Singleton(pvt:PrivateClass){ } public static function getInstance():Singleton { if(Singleton._instance==null){ Singleton._instance=new Singleton(new PrivateClass()}; } return Singleton._instance; } } } //END OF PACKAGE //Private class class PrivateClass { public function PrivateClass(){} }
The advantage is that the private class used in the constructor is visible only in the Singleton class because it is defines outside the package.
Indeed the code following in another class raise an error after compilation.
Singleton s=new Singleton(new PrivateClass())};
Here is an elegant way to implement this pattern.

• access to local resources (files, applications, USB, serial, Bluetooth) is an argument to look to the RDA. Although this can be remedied with an applet and increasingly with Gears (but it’s a RWA/RDA mix, why not is what I do) and that the Flash plugin already allows access to the camera.
• the concept of “push” to send data to a client from the server is now possible with RWA (Comet, reverse Ajax) and soon standarize in HTML 5 (WebSocket).
• exchanges via asynchronous MOM with queues client side cannot yet be in RWA. Gears should propose an API and LifeCycle Data Service does not really do it because the queue is server side.
• uniformity of application with a single platform deployment independent of the OS is probably the most powerful argument for the SI to choose a RWA

Note that this is the first of a (hopefully) long series of Zenika event, so thanks again and see you next time …