Simple Java binary search implementation in log(n):

```
public static int searchInsert(int[] nums, int target) {
int left = 0, right = nums.length -1;
while(left <= right) {
int mid = left + (right - left) / 2;
if(nums[mid] == target) {
return mid;
} else if (nums[mid] > target) {
right = mid - 1;
} else {
left = mid + 1;
}
}
return left;
}
```