Printing message on Console without using main() method

Question

I was asked this question in an interview.

How to print message on console without using main() method?

Answer 1

You could define a custom class loader that prints your message :

public class MyClassLoader extends ClassLoader {
    public MyClassLoader(ClassLoader other) {
         super(other);
         System.out.println("Hi there");
         System.exit(0);
    }
}

Then run the java command :

java -Djava.system.class.loader=MyClassLoader

(don't need to add a class as parameter)