【DataStructure】Charming usage of Set in the java

In an attempt to remove duplicate elements from list, I go to the lengths to take advantage of  methods in the java api. After investiagting the document of java api, the result is so satisfying that I speak hightly of wisdom of developer of java language.Next
I will introduce charming usage about set in the java.

[java] view
plaincopy

1. import java.util.ArrayList;
2. import java.util.Arrays;
3. import java.util.Collections;
4. import java.util.HashSet;
5. import java.util.List;
6. import java.util.Set;
7. import java.util.TreeSet;
8. public class SetUtil
9. {
10. public static List<String> testStrList = Arrays.asList("Apple", "Orange",
11. "Pair", "Grape", "Banana", "Apple", "Orange");
12. /**
13. * Gets sorted sets which contains no duplicate elements
14. *
15. * @time Jul 17, 2014 7:58:16 PM
16. * @return void
17. */
18. public static void sort()
19. {
20. Set<String> sortSet = new TreeSet<String>(testStrList);
21. System.out.println(sortSet);
22. // output : [Apple, Banana, Grape, Orange, Pair]
23. }
24. public static void removeDuplicate()
25. {
26. Set<String> uniqueSet = new HashSet<String>(testStrList);
27. System.out.println(uniqueSet);
28. <span style="font-family: Arial, Helvetica, sans-serif;">// output : </span><span style="font-family: Arial, Helvetica, sans-serif;">[Pair, Apple, Banana, Orange, Grape]</span>
29. }
30. public static void reverse()
31. {
32. Set<String> sortSet = new TreeSet<String>(testStrList);
33. List<String> sortList = new ArrayList<String>(sortSet);
34. Collections.reverse(sortList);
35. System.out.println(sortList);
36. // output : [Pair, Orange, Grape, Banana, Apple]
37. }
38. public static void swap()
39. {
40. Set<String> sortSet = new TreeSet<String>(testStrList);
41. List<String> sortList = new ArrayList<String>(sortSet);
42. Collections.swap(sortList, 0, sortList.size() - 1);
43. System.out.println(sortList);
44. output : [Apple, Orange, Grape, Banana, Pair]
45. }
46. public static void main(String[] args)
47. {
48. SetUtil.sort();
49. SetUtil.reverse();
50. SetUtil.swap();
51. SetUtil.removeDuplicate();
52. }
53. }