Final class and loading

[P. Ingle]

Hello,

I have a final class with all static methods and no instance varibles in it. I need this class in "Application Scope". Do I need to instatiate it some where( if so where) or JVM Loads it automatically. (When I say final class with all static methods, you can think it being very similar to Math class)

Thanks,
P Ingle

[James Carman]

That's the problem with static classes such as Math, there is no real object to put into "application scope." That's why Jakarta Commons BeanUtils went to a more bean-like approach with its classes like BeanUtils and PropertyUtils.

[P. Ingle]

being a newbie to J2EE and whole Jacarta Apachi project I have to ask - what would that approach be?

Thanks,
P Ingle

[James Carman]

The static methods delegate to an instance method...

  
public class Utilities
{
  private static UtilitiesBean utlitiesBean;
 
  public static void someMethod()
  {
    utilitiesBean.someMethod();
  }
}
 
public class UtilitiesBean
{
  public void someMethod()
  {
  }
}

[P. Ingle]

Interesting. How does it behave under Heavy Loads - If I had to use this pattern to implement Class that hands out database connactions or for DAOFactory in high traffic web app, would this be a bottleneck?

Thanks,
P. Ingle
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Questions, Questions and more Questions.

[Ilja Preuss]

No, it doesn't cause any performance bottlenecks, but it's also not necessary to load a class. The class will simply be loaded when needed, at least before the first static method is called.

The solution shown by James is interesting when you want to change the behaviour at runtime - it's basically a variation of the Strategy pattern, as far as I can tell.