Insertion Sort

/**
 * Write a description of class Insertion_Sort here.
 *
 * @Samuel Berkat Hulu
 * @version 5.0
 */
public class Insertion_Sort
{
    public static void insertionSort(int arr[]) {
        for (int j = 1; j < arr.length; j++) {
            int key = arr[j]; int i = j-1;
                while ( (i > -1) && ( arr[i] > key ) ) {
                    arr[i+1] = arr[i]; i--;
                    }
                        arr[i+1] = key;
                }
}
    static void printArray(int arr[]) {
        int len = arr.length;
            for (int i= 0; i<len; i++)
                System.out.print(arr[i] + " " );
                    System.out.println();
}
    public static void main(String args[]){
        int[] arr1 = {21,18,15,23,52,12,61};
            System.out.println("Array sebelum penyisipan:");
                printArray(arr1);
                  insertionSort(arr1);
            System.out.println("Array array setelah penyisipan:");
                printArray(arr1);
}
}