Java exception throw

How to throw an exception in Java, tried code below but it raised a compilation error

class Demo{
    public static void main(String args[]) {
        throw new Exception("This is not allowed");
    }
}

Answer

Exception and its subclasses (besides RuntimeException and its subclasses) cannot be thrown without a try-catch clause, or a throws Exception in the method declaration.

You'll need to declare your main as

public static void main(String[] args) throws Exception {

or instead of an Exception, throw a RuntimeException (or its subclass).