クイックソート(QuickSort)Java実装

public class QuickSort {

    /**
     *  
     * @param data  
     * @param startIndex  
     * @param endIndex  
     */
    public static void sort(Comparable[] data, int startIndex, int endIndex) {
        if (startIndex < endIndex) {
            int middleIndex = partition(data, startIndex, endIndex);
            sort(data, startIndex, middleIndex - 1);
            sort(data, middleIndex + 1, endIndex);
        }
    }

    public static void sort(Comparable[] data) {
        sort(data, 0, data.length - 1);
    }

    public static void sort(Comparable[] data, int startIndex) {
        sort(data, startIndex, data.length - 1);
    }

    private static int partition(Comparable[] data, int startIndex, int endIndex) {
        Comparable pivotElement = data[endIndex];
        int i = startIndex - 1;
        for (int j = startIndex; j < endIndex; j++) {
            if (data[j].compareTo(pivotElement) < 0) {
                swap(data, ++i, j);
            }
        }
        swap(data, ++i, endIndex);
        return i;
    }

    private static void swap(Comparable[] data, int i, int j) {
        Comparable tmp = data[i];
        data[i] = data[j];
        data[j] = tmp;
    }