JAVA

do i have to use static methods in java main

Use a static method 
when you want to be able to access the method 
without an instance of the class

how to call a static method in java

class scratch{
	public static hey(){
		System.out.println("Hey");
    }
	public static void main(String[] args){
		hey();
        //print Hey to the console
    }

Calling Static Method in Java

class StaticMethod
{
public static void main(String args[]) 
{
int num;
num=Math.min(21,12);
System.out.println("Minimum number is: " + num);
}
}