The command line argument is the argument passed to a program at the time when you run it. To access the command-line argument inside a java program is quite easy, they are stored as string in String array passed to the args parameter of main()
method.
Example
class cmd
{
public static void main(String[] args)
{
for(int i=0;i< args.length;i++)
{
System.out.println(args[i]);
}
}
}
Execute this program as java cmd 10 20 30
10 20 30