How do you do binary search in java?

Problem statement: How will you do for binary search in java?

1. public class BinarySearchExe {
2. public static void main(String[] args) {
3. int a[] = { 2, 4, 5, 6, 7, 9, 10 };
4. int idx = binarySearch(a, 10);
5. System.out.println(idx);
6. } // end of main
7. static int binarySearch(int a[], int key) {
8. int start = 0, end = a.length - 1;
9. while (start <= end) {
10. int mid = (start + end) / 2;
11. if (key == a[mid]) {
12. return mid;
13. } else if (key > a[mid]) {
14. start = mid + 1;
15. } else {
16. end = mid - 1;
17. }
18. }
19. return -1; // if key does not found, return -1
20. } // end of binarySearch method
21. }

Output: 6