排序函数

Arrays.sort

Collections.sort

排序集合

TreeSet   TreeMap   

示例

public class Test1_1 {

        private static Randomrandom =new Random();

        public static void main(String[] args) {

                int size =10000;

                Integer[] a =initArray(size);

                Arrays.sort(a);

                Collections.sort(Arrays.asList(a));

                long starttime =System.currentTimeMillis();

                TreeSet set =new TreeSet();

                set.addAll(Arrays.asList(a));

                a = set.toArray(new Integer[0]);

                System.out.println("耗时："+(System.currentTimeMillis()-starttime)+"ms");

printArray(a);

        }

private static Integer[] initArray(int size) {

            Integer[] a =new Integer[size];

            for (int i =0; i < size; i++) {

                    a[i] =random.nextInt(1000000000);

            }

            return a;

}

    private static void printArray(Integer[] a) {

                for (Integer temp : a) {

                        System.out.println(temp);

                }

}