Discussions

EJB design: Any better solution for system properties?

Bookmark and Share Get thread feed

  1. Any better solution for system properties? (7 messages)

    • Posted by: Wallace Zou
    • Posted on: June 09 2003 15:41 EDT
    Hello everybody,

    In EJB 2.0, we can get some environment propertise from ejb-jar. This is very useful for constant import. But I was noted that the above machnism is for a bean, not for entire application/system. Our application needs some important parameters to be initiated at starting time, it is better I can store those parameters out of code. The bean's environment property solution is not good for me, cause it work for specific bean, do you guys know how should I do this?

    Thanks a lot!
    Wallace
    Reply to this

    Threaded Messages (7)

  2. You need a Singleton Property file manager[ Go to top ]

    If you need a global manager for loading and initializing properties that will be available to all components in your ejb and web containers, then I would suggest using a simple property file. Create a singleton manager that loads the property file and stores it inside a static hashmap and makes it available to calling components via PropertyFileManager.getResource("myProperties.properties"), or something like that.

    Since the property file manager is a singleton, all requests are centralized to a single class, preventing the property file from being loaded twice.

    That's one suggestion.

    Raffi
    Reply to this Reply to original

  3. You need a Singleton Property file manager[ Go to top ]

    Oh, yeah, singleton is a good choice.

    :->

    .....why am I forgot it?...

    Thanks,
    Wallace
    Reply to this Reply to original

  4. once more[ Go to top ]

    I could use a singleton to load parameter at once system start, but I have to transfer a OS dependent parameter to this singleton (example, the config XML file name). If I migrate system from WIN to UNIX, I still have to modify code and compile to run. How to prevent modify code?

    Thanks for your advice.

    Wallace
    Reply to this Reply to original

  5. once more[ Go to top ]

    one way is to avoid the problem that you are explaining is to :

    use a startup class to load the singleton ... pass the OS specific parameter through weblogic startxxxServer.xml as a parameter to the startup class...

    I think startup class feature is available in weblogic and websphere (latest)
    Reply to this Reply to original

  6. once more[ Go to top ]

    That will be great if J2EE has such definition in specification.

    Regards,
    Wallace
    Reply to this Reply to original

  7. OS specific what?[ Go to top ]

    What is specific to the OS? I use a singleton property file manager on both Windows and Solaris and I don't have to pass anything when switching environments. I would not use a startup class either to initialize the singleton, I would simply use a static initializer in the singleton class to perform any initialization. No need to complicate things when the class itself already provides a run-once start-up mechanism, hence the static initializer.

    Raffi
    Reply to this Reply to original

  8. Put the property file in your classpath[ Go to top ]

    There is no need to have anything OS specific. Just put the property file in your classpath then use the ClassLoader.getResource() to look it up.
    Reply to this Reply to original