java - Null Pointer exeception handler -


i have made function in fouractivity class:

public int getrandomnumber(){     random rnd=new random();     int randomnumber=rnd.nextint(100);       if (randomnumber%2==1){         randomnumber=randomnumber+1;         return randomnumber;      }      else return randomnumber; }

i trying access method in class through way. throws java.lang.nullpointerexception: 

int randomnumber; fouractivity fouractivity; randomnumber= fouractivity.getrandomnumber();  toast.maketext(finalactivity.this,"random number is"+randomnumber ,toast.length_short).show();

fouractivity not instantiated, that's why nullpointerexception.

if activity, shouldn't using that, instead create , use static method:

fouractivity.getrandomnumber();

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