In your spirit of using only raw arrays and not the collections framework like ArrayList, this is how I would reimplement your even() function:
int[] temp = new int[array.length]; int n = 0; // Prefix length of temp for (int val : array) { if (val % 2 == 0) { temp[n] = val; n++; } } return Arrays.copyOf(temp, jn); // Truncate