parameter errorJava main怎么判断传入参数为空？程序报错？？？

Java main怎么判断传入参数为空？程序报错？？？

public?static?void?main(String[]?args){ ????if?(args==null?||?args[0].length()<1){ ??????????System.out.println("parameter?error"); ????}?else?{ ??????????int?num=Integer.parseInt(args[0]); ??????????if(10<=num?&&?num<=20){ ??????????????JunglePartyExtra?party=new?JunglePartyExtra(num); ??????????}?else{ ??????????????System.out.println("error"); ??????????} ????} ??}