【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.

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import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashSet;

import java.util.List;

import java.util.Set;

import java.util.TreeSet;

public class SetUtil

{

public static List<String> testStrList = Arrays.asList("Apple", "Orange",

"Pair", "Grape", "Banana", "Apple", "Orange");

/**

* Gets sorted sets which contains no duplicate elements

*

* @time Jul 17, 2014 7:58:16 PM

* @return void

*/

public static void sort()

{

Set<String> sortSet = new TreeSet<String>(testStrList);

System.out.println(sortSet);

// output : [Apple, Banana, Grape, Orange, Pair]

}

public static void removeDuplicate()

{

Set<String> uniqueSet = new HashSet<String>(testStrList);

System.out.println(uniqueSet);

<span style="font-family: Arial, Helvetica, sans-serif;">// output : </span><span style="font-family: Arial, Helvetica, sans-serif;">[Pair, Apple, Banana, Orange, Grape]</span>

}

public static void reverse()

{

Set<String> sortSet = new TreeSet<String>(testStrList);

List<String> sortList = new ArrayList<String>(sortSet);

Collections.reverse(sortList);

System.out.println(sortList);

// output : [Pair, Orange, Grape, Banana, Apple]

}

public static void swap()

{

Set<String> sortSet = new TreeSet<String>(testStrList);

List<String> sortList = new ArrayList<String>(sortSet);

Collections.swap(sortList, 0, sortList.size() - 1);

System.out.println(sortList);

output : [Apple, Orange, Grape, Banana, Pair]

}

public static void main(String[] args)

{

SetUtil.sort();

SetUtil.reverse();

SetUtil.swap();

SetUtil.removeDuplicate();

}

}