roughly...

int range = 100;
boolean prime  = true;

for(int i=0; i!=range; i++)
{
for (int j=0; j!=i; j++)
{
if ( i mod j == 0 )
prime=false;
break;
}

if(prime)
{
// caught prime number
}

}

basically though, it is better to store found prime numbers in an
ArrayList. Then you can check  prime numbers in the array list, and
then those numbers that are larger than the largest known prime
number.

To find if a number is prime, use the inner for loop.