Error message wehn i run the code

[Bassam Bibo]

Hello dear friends,

i just start with java "Head first java from sierra & bates" the german version. wehn i start the code "after compiling" in the first example i get this error message :

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


and this is the code what i use :

import java.awt.*;
import java.awt.event.*;
class Party{

 public void erstelleEinladung(){
 Frame f = new Frame();
 Label l = new Label("Party bei Tim");
 Button b = new Button("Sicher doch");
 Button c = new Button("Ohne mich");
 Panel p = new Panel();
p.add(l);
} 
}

can somebody tell me where my fault is?


PS: sorry for my bad bad english

[Greg Brannon]

In the main public class in the file with the same name that you've called at the command line, Java looks for a method called main() with the signature

public static void main( String[] args )
{
    // code here
}

as the starting point for program execution. If the file containing the class you run does not have the main() method, you'll get the error you posted.

That should be explained in your book.

[Campbell Ritchie]

It says at the bottom of page 3 "you'll be writing real code in a minute". Maybe it should have said "you can't execute the Party class as it stands".

[Eduardo Hernandez]

The entry point of a Java program is the main method, the signature of main must look like this: public static void main(String[] args) { }. When you execute (run) a java program the JVM looks for the main method in your class (program) to start executing your program's instructions if it can't find the main method definition the JVM complains and displays that error.

[Shubham Chhabra]

The main() method is the entry point in the program. So you have to put main method in your program. If you do not put main()method your program will compile put will not run. The java interpreter will search for main method and call JVM to load the nessary classes and interfaces. You have to put the main method in some class.


public static void main(String s[])
{
}

[Campbell Ritchie]

Shubham Chhabra, welcome to the Ranch