Java链表的排序

package struct;import java.util.ArrayList;import java.util.Collections;import java.util.TreeSet;public class Comp implements Comparable<Comp>{private int x;private int y;@Overridepublic int compareTo(Comp o) {return x-o.x;}Comp(int x,int y){this.x=x;this.y=y;}@Overridepublic String toString() {// TODO Auto-generated method stubreturn x+" "+y;}public static void main(String []args){Comp c1 = new Comp(3,3);Comp c2 = new Comp(1,1);Comp c3 = new Comp(5,3);Comp c4 = new Comp(4,3);TreeSet<Comp>treeSet1 = new TreeSet<Comp>();System.out.println(treeSet1.add(c1));System.out.println(treeSet1.add(c2));System.out.println(treeSet1.add(c3));System.out.println(treeSet1.add(c4));for (Comp comp : treeSet1) {System.out.println(comp);}ArrayList<Comp> list = new ArrayList<Comp>();list.add(c1);list.add(c2);list.add(c3);list.add(c4);Collections.sort(list);for (Comp comp : list) {System.out.println(comp);}}}