test.java

int[] arr = {1,2,7,4,5,7,5,7,6,7,0,-1,22,15};
Arrays.sort(arr);
for (int i = 0; i < arr.length; i++) {
    System.out.println(i + " : " + arr[i]);
}
System.out.println("RES:");
int match = Arrays.binarySearch(arr, 7);
if (match >= 0) {
    int first = match;
    int last = match;
    while (first > 0 && arr[first - 1] == arr[match]) 
        --first;
    while (last < arr.length - 1 && arr[last+1] == arr[match])
        ++last;
    System.out.println("Matches " + first + " " + last);
}