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Re: Eclipse - NoSuchMethodError: main

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On 03/21/2012 08:46 PM, Eric Sosman wrote:
> On 3/21/2012 10:17 AM, William Colls wrote:
>> I think this is really an Eclipse problem.
>>
>> When I try to run my program, I get the error message
>>
>> NoSuchMethodFound: main
>>
>> The file does in fact contain a main method, declared as public static
>> void, with no arguments.
>>
>> I suspect that Eclipse is looking in the wrong place for the method, but
>> in every place that I can find in the various configurations, the file
>> that I am running is identified as the file containing containing the
>> main() method.
>>
>> Any suggestions as to where further to look will greatfully received.
>
> Others have explained that "main" must have a parameter list
> consisting of exactly one String array. For completeness' sake,
> it's *possible* to have a "main" with some other signature; as with
> any other method, you can overload "main" as you wish:
>
> public static void main(String[] args) { ... }
> public static int main() { return 42; }
> public static double main(String justOneArg) {
> return Double.parseDouble(justOneArg);
> }
> ...
>
> However, the particular "main" that Java (not just Eclipse) looks
> for when starting execution is the one and only "main" that has the
> first form above. (You can write "String... args" instead of
> "String[] args" if you like, but it's the same thing. Java starts
> with the "main" whose parameter list is one String array, however
> you happen to express it.)
>
> Only the type of the formal parameter matters; the actual name
> is irrelevant. When the arguments aren't used, my own personal
> practice is to write
>
> public static void main(String[] unused) { ... }
>
> The only drawback is that code-policing tools sometimes insist
> that I write Javadoc comments for the "unused" parameter ;-)
>
Thanks to all who replied. I changed the the signature to

public static void(String[] args)

but it made no difference - same problem.

I made the assumption that it was/is an Eclipse configuration issue, 
based on the fact that When I first started with Java, I was using the 
Netbeans IDE, and the main() worked perfectly well there, but I would 
get the NoSuchMethodError if project setup page didn't point to the 
correct file.

I have side-stepped the problem by creating a small class that does have 
a main method, imports the class I have defined and am building, and 
then instansiates an object form it, and invokes the methods I need to 
test. Better solution, as it more closely the real world use of the work 
I am doing.

Again thanks to all for your helpful responses.

William.

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Thread

Eclipse - NoSuchMethodError: main William Colls <william.colls@rogers.com> - 2012-03-21 10:17 -0400
  Re: Eclipse - NoSuchMethodError: main Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2012-03-21 16:41 +0200
  Re: Eclipse - NoSuchMethodError: main markspace <-@.> - 2012-03-21 08:18 -0700
  Re: Eclipse - NoSuchMethodError: main Lew <lewbloch@gmail.com> - 2012-03-21 13:41 -0700
  Re: Eclipse - NoSuchMethodError: main Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-03-21 20:46 -0400
    Re: Eclipse - NoSuchMethodError: main Arne Vajhøj <arne@vajhoej.dk> - 2012-03-21 21:00 -0400
      Re: Eclipse - NoSuchMethodError: main BGB <cr88192@hotmail.com> - 2012-03-21 21:59 -0700
        Re: Eclipse - NoSuchMethodError: main Patricia Shanahan <pats@acm.org> - 2012-03-22 03:13 -0700
          Re: Eclipse - NoSuchMethodError: main Arne Vajhøj <arne@vajhoej.dk> - 2012-03-22 21:46 -0400
            Re: Eclipse - NoSuchMethodError: main Lew <lewbloch@gmail.com> - 2012-03-22 18:49 -0700
              Re: Eclipse - NoSuchMethodError: main Gene Wirchenko <genew@ocis.net> - 2012-03-22 22:17 -0700
    Re: Eclipse - NoSuchMethodError: main William Colls <william.colls@rogers.com> - 2012-03-23 09:36 -0400
      Re: Eclipse - NoSuchMethodError: main Lew <noone@lewscanon.com> - 2012-03-23 07:51 -0700
        Re: Eclipse - NoSuchMethodError: main Patricia Shanahan <pats@acm.org> - 2012-03-23 08:49 -0700
  Re: Eclipse - NoSuchMethodError: main Jan Burse <janburse@fastmail.fm> - 2012-03-23 18:05 +0100

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