Sorting Algorithms (Bubble sort, Selection sort & Insertion Sort)

I want to refresh my mind about sorting algorithms and here are the first three simple sorting algorithms in this article - Bubble Sort, Selection Sort and Insertion Sort. I attribute the explanations to Wikipedia.

import java.util.Random;

public class SortingAlgorithm {

 private final int SIZE = 2000;
 private Random myRand = new Random();
 private int[] numbers = new int[SIZE];

 public SortingAlgorithm(){}

 private void randomizeNumbers(){
  for (int i = 0; i < numbers.length; i++) {
   numbers[i] = myRand.nextInt( 2000 ) + 1;
  } 
 }

 private void printArray(){
  for(int i: numbers){
   System.out.print(i + " ");
  }
  System.out.println();
 }

 public void bubbleSort() {
  randomizeNumbers();
  System.out.println("BUBBLE SORT");
  System.out.println("Presorted numbers: ");
  printArray();
  long start = System.nanoTime();

  /**
   * Bubblesort algorithm
   * Wikipedia:
   * works by repeatedly stepping through the list to be sorted, 
   * comparing each pair of adjacent items and swapping them if 
   * they are in the wrong order. The pass through the list is 
   * repeated until no swaps are needed, which indicates that the 
   * list is sorted. The algorithm gets its name from the way smaller 
   * elements "bubble" to the top of the list.
   * Complexity: 
   * Worst = O(n^2)
   * Average = O(n^2)
   * Best = O(n)
   */
  int n = numbers.length;
  for (int pass=1; pass < n; pass++) { 
   for (int i=0; i < n-pass; i++) {
    if (numbers[i] > numbers[i+1]) {
     int temp = numbers[i];  
     numbers[i] = numbers[i+1];  
     numbers[i+1] = temp;
    }
   }
  }

  long elapsed = (System.nanoTime() - start);
  System.out.println("Bubble-sorted numbers: ");
  printArray();
  System.out.println("Elapsed time: " + elapsed + "ns\n");
 }

 public void selectionSort(){
  randomizeNumbers();
  System.out.println("SELECTION SORT");
  System.out.println("Presorted numbers: ");
  printArray();
  long start = System.nanoTime();

  /**
   * Selectionsort Algoritm
   * Wikipedia:
   * 1. Find the minimum value in the list
   * 2. Swap it with the value in the first position
   * 3. Repeat the steps above for the remainder of the list (starting 
   *    at the second position and advancing each time)
   * Complexity:
   * Worst = O(n^2)
   * Average = O(n^2)
   * Best = O(n^2)
   */
  for (int i=0; i<numbers.length-1; i++) {
   int minIndex = i;
   for (int j=i+1; j<numbers.length; j++) {
    if (numbers[minIndex] > numbers[j]) {
     minIndex = j;
    }
   }
   if (minIndex != i) { 
    int temp = numbers[i];
    numbers[i] = numbers[minIndex];
    numbers[minIndex] = temp;
   }
  }

  long elapsed = (System.nanoTime() - start);
  System.out.println("Selection-sorted numbers: ");
  printArray();
  System.out.println("Elapsed time: " + elapsed + "ns\n");
 }

 public void insertionSort(){
  randomizeNumbers();
  System.out.println("INSERTION SORT");
  System.out.println("Presorted numbers: ");
  printArray();
  long start = System.nanoTime();

  /**
   * Insertionsort Algorithm
   * Wikipedia:
   * much less efficient on large lists than more advanced algorithms 
   * such as quicksort, heapsort, or merge sort. However, insertion sort 
   * provides several advantages:
   * 1. simple implementation
   * 2. efficient for (quite) small data sets
   * 3. adaptive, i.e. efficient for data sets that are already substantially 
   *    sorted: the time complexity is O(n + d), where d is the number of inversions
   * 4. more efficient in practice than most other simple quadratic (i.e. O(n^2)) algorithms 
   *    such as selection sort or bubble sort
   * Complexity:
   * Worst = O(n^2)
   * Average = O(n^2)
   * Best = O(n)
   */
  int in, out;
  for(out=1; out<numbers.length; out++){
   int temp = numbers[out];
   in = out;
   while(in>0 && numbers[in-1] >= temp){
    numbers[in] = numbers[in-1];
    --in;
   }
   numbers[in] = temp;
  }

  long elapsed = (System.nanoTime() - start);
  System.out.println("Insertion-sorted numbers: ");
  printArray();
  System.out.println("Elapsed time: " + elapsed + "ns\n");
 }

 public static void main(String[] args) {
  SortingAlgorithm sa = new SortingAlgorithm();
  sa.bubbleSort();
  sa.selectionSort();
  sa.insertionSort();
 }
}