Java SE treeset implement comparator interface yourself

1-Letter Comparator Implementation method code in reverse order

Import Java.util.Comparator;
Import Java.util.Iterator;
Import Java.util.TreeSet;


public class TreeSetTest3 {public
	static void Main (string[] args) {
		TreeSet set = new TreeSet (new Mycomparator ()) ;
		
		Set.add ("C");
		Set.add ("A");
		Set.add ("B");
		Set.add ("E");
		Set.add ("F");
		Set.add ("D");
		
		for (Iterator iter = Set.iterator (); Iter.hasnext ();) {
			String value = (string) iter.next ();
			System.out.println (value);

}}  Class Mycomparator implements comparator{
	@Override public
	int Compare (object O1, Object O2) {
		String S1 = (String) O1;
		String s2 = (string) O2;
		Return S2.compareto (S1);
	}

2 people in ascending order to achieve the comparator interface method, the source code is as follows

Import Java.util.Comparator;
Import Java.util.TreeSet;


public class TreeSetTest2 {public
	static void Main (string[] args) {
		
		TreeSet set = new TreeSet (New Mycomparator2 () );
		
		person P1 = new person (a);
		person P2 = new person (a);
		Person P3 = new person (a);
		person P4 = new person (n);
		
		Set.add (p1);
		Set.add (p2);
		Set.add (p3);
		Set.add (p4);
		
		SYSTEM.OUT.PRINTLN (set);
	}

Class person{
	
	int score;
	Public person (int score) {
		this.score = score;
	}
	
	@Override public
	String toString () {return
		string.valueof (this.score);
	}
}

Class Mycomparator2 implements comparator{
	@Override public
	int Compare (object O1, Object O2) {person
		
		p1 = (person) O1;
		person P2 = (person) O2;
		if (P1.score>p2.score) {return
			1;
		}
		if (P1.score==p2.score) {return
			0;
		}
		Return-1
	}
}

3 This uses a policy pattern.