Main method inheritance

[Vaibhav Wahee]

Please look at the very simple code below...

  class Main
{
public static void main(String args[])
{
System.out.println("Hi");
}
}
class Main2 extends Main
{ }  

My question is when the Main2 inherits the main method... then why can'nt the execution of the program be started by saying
java Main2

Why can'nt the java interpreter call the main method from class Main2 when it inherits the main method from class Main ?

Any answers ?

[Vaibhav Wahee]

Can someone come up with the answer ?

[Olivier Croisier]

The "main" method is static, and thus is not inherited.
So you cannot call it from your Main2 class.
[ June 19, 2007: Message edited by: Olivier Croisier ]

[Vaibhav Wahee]

Nope static methods are indeed inhertied...

for example

   
class Main2{
public static void display()
{ System.out.println("In Main2's Static");
}
 class Main extends Main2
{
  public static void main(String args[])
  { Main m2= new Main();
   m2.display();
  } 
  } 

[Manfred Klug]

Originally posted by bhaskar:
My question is when the Main2 inherits the main method... then why can'nt the execution of the program be started by saying
java Main2

It works for me without problems.

java version "1.5.0_11"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_11-b03)
Java HotSpot(TM) Client VM (build 1.5.0_11-b03, mixed mode)

[Vaibhav Wahee]

Thanks Manfred...for your prompt reply

But my version of java is Version 1.5.0 (build 1.5.0_09-b03) and the code mentioned in my question does'nt run...

and could you please tell what is mixed mode ?

[Bear Bibeault]

"bhaskar", you have previously been warned on one or more occasions regarding adjusting your display name to meet JavaRanch standards. This is not optional. Please take a look at the JavaRanch Naming Policy and adjust your display name to match it prior to your next post.

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JavaRanch Sheriff

[Vaibhav Wahee]

Sorry about the name glitch...i am now using my real name.

[Ernest Friedman-Hill]

When you try to run this program, what error message do you get? My belief is that it should work fine.

[Vaibhav Wahee]

i am using net beans and why i try to run Main2.java it says Main2 does not have a main methoid

i even tried to run the code on the command prompt but it gives error
"Exception in thread main java.lang.NoClassDefFoundError: Main2"

why so i don'nt know..

my java version is displayed above in this page

[Ernest Friedman-Hill]

I think you may just be having a bookkeeping/CLASSPATH/rebuilding problem, or something like that. Start from the beginning, carefully, and see if you can't make it work.

[Amrit Kashyap]

hi bhaskar

it's working for me with following settings:

java version "1.4.2_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_06-b03)
Java HotSpot(TM) Client VM (build 1.4.2_06-b03, mixed mode)

there may be some other setting, which you may be missing.

[raj malhotra]

Nope static methods are indeed inhertied...

Facts Regarding Static method:
A static method cannot override an inherited instance method,but it can hide a static method if the exact requirements for overriding instance methods are fulfilled.The compiler will flag an error if the signatures are the same but the other requirements regarding return type,throws clause,and accessiblity are not met.If the signatures are different ,the method name is overloaded. -source khalid mughal

[Raghavan Muthu]

Have you checked your classpath?

[Raghavan Muthu]

Hi,

I use JDK 1.4.2_05. For me also it works fine. Just check your classpath or buildpath as Ernest Friedman-Hill pointed out.

[Bert Bates]

it's a fine discussionm and for the benefit of those who are focusing their studies on the scjp exam, you should know that this topic is not on the exam.

[Raghavan Muthu]

Thanks Bert for giving an useful info in time!