can anyone explain about singleton object and its use ....
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can anyone explain about singleton object and its use ....
It's all about a design pattern. I think it's better to find a article and read. Just Google it, you have a large number of such.
Read this article...
Once you've read what it is, please search google for all the reasons you should not use it.
Such as "Singleton Considered Stupid "
And check into the JUnit groups and see how using Singletons makes proper unit testing much harder.
In general, a Singleton is just a wad of global stuff. Good OO design avoids global stuff, as it increases coupling.
Yes, good OO should be about abstractions and isolation. Coupling has been proven to make systems exponentially complex.
Sadly, a lot of Java, even professionally developed Java is not very good OO.
This bad Java will be the Year 2000 Cobol problem of the future, probably in five years or so.
Lots of people working on Java(other languages too) without knowing any about OO. Some people don't want to use it either. I don't know why, but in later they found full wired with further maintainability and expandability of the application.
I think part of it is that Java was cursed with a C-foundation, which greatly helped acceptance at first, but enables bad practices.
I did some professional Smalltalk, and while it wasn't long term useful (Smalltalk is dead) it forced you to think about OO seriously.
For a lot of applications, especially in the business domain, OO hasn't worked well. It works great for GUIs and other user interfaces, but gets hard to do with a payroll record.
Our continued use of Relational DBMS doesn't help.
This is probably moving a bit OT, probably should go into a less specific thread.
I'm not quite following this, perhaps its an idiom? or maybe typo? What is "fully wired" in this context? Thanks Pat
Yes, seems now this is going out of the scope of this thread. Lets try is on different place...