Execution error: NoSuchMethodError: Main

**kjharn** · 11-02-2009, 06:44 PM

Hello all,

I have an assignment due (today, of course) and the instructor outlines in the assignment sheet that we need to declare main using:

Java Code:

public static int main (String args[])

The program compiles correctly, naturally, but when executing it says this:

Java Code:

Exception in thread "main" java.lang.NoSuchMethodError: main

Normally this error is pretty simple to diagnose, since usually in that case main is missing entirely. Anyways, I realize there are some logical errors in this programs, and some overly complex ways of doing things... Gotta do it the way the instructor says.

Can anyone shed some light on this problem? Thanks a lot guys

Heres the complete code:

Java Code:

import java.util.Scanner;

public class kharnden_Decimal
{
static int con;

	public static int main( String args[] )
	{
		Scanner sc = new Scanner(System.in);	
		System.out.print("Enter a positive number up to 8 digits (Fmt: 00000000)");
		con = sc.nextInt();
		System.out.print(con + ":" + convert(con));
		return con;
	}

	public static int convert ( int octalNumber)
	{
		int d1, d2, d3, d4, d5, d6, d7, d8;
		String in = Integer.toString(con);
		d1 = in.charAt(0) - 48;
		d2 = in.charAt(1) - 48;
		d3 = in.charAt(2) - 48;
		d4 = in.charAt(3) - 48;
		d5 = in.charAt(4) - 48;
		d6 = in.charAt(5) - 48;
		d7 = in.charAt(6) - 48;
		d8 = in.charAt(7) - 48;

		con = (d1 * 8^7) + (d2 * 8^6) + (d3 * 8^5) + (d4 * 8^4) + (d5 * 8^3) + (d6 * 8^2) + (d7 * 8^1) + (d8 * 8^0);
		return con;
	}
}

**r035198x** · 11-02-2009, 06:46 PM

Your instructor is on drugs. The main method must be void.
It must not return an int.

**kjharn** · 11-02-2009, 06:58 PM

Figures. Now that I fixed that, just gotta figure out an easier way to convert oct to dec... Also one that works...

Thanks!

**r035198x** · 11-02-2009, 07:14 PM

What happens if the silly user enters a 3 digit number (or any n<8 digit number)?
Better split that string into characters using the String.toCharArray method. Then you can loop through the array form the last position moving to the left.

P.S You could also simply cheat and use Integer.toString() method that takes two int arguments. Read the API specs for it.