reflections/default-constructor issue

[DoraC]

Hi,

Unless I'm mistaken, default constructors (i.e. no arguments) are automatically provided for a class if you opt not to explicitly provide one yourself.

So, I'm contending with the following:

class MyClass
{
}

MyClass Fubar = new MyClass();

Constructor ct = ( Fubar.getClass() ).getConstructor(null);

When I define a default constructor (i.e. public MyClass(){} )
for class MyClass, this all works fine. However, when I don't define this default constructor, a "NoSuchMethodException" is generated. Why would this be, if a default constructor is provided for me??

Thanks for any/all help!
dora

 

[scrat]

How interesting. Yes, Java provides default constructors but I suspect Java does a special and actually makes the default constructor as required if it cannot find another constructor. getConstructor() only displays real constructors.

Not much help really...

scrat

 

[idarke]

I've always been skeptical about the existence of default constructors.

Since they do nothing and return nothing, how can you tell if they exist? If you were writing a JVM, would you put in special code to generate a constructor that did nothing? Wouldn't such a method get optimized right back out again? In a language that has struggled to achieve acceptable performance speed, it would seem expendable.

I think Dora has discovered the truth. I guess you catch the exception and ignore it.