TreeSet集合

package peterxiazhe;

import java.util.Comparator;
import java.util.Iterator;
import java.util.Set;
import java.util.TreeSet;

public class test4 {
    public static void main(String[] args) {
        Set<Integer> set = new TreeSet<Integer>();
        
        //自然排序
        set.add(2);
        set.add(3);
        set.add(6);
        set.add(10);
        System.out.println(set);
        
        set.remove(6);
        System.out.println(set);
        
        System.out.println(set.contains(10));
        
        for(Integer obj: set) {
            System.out.println(obj);
        }
        
        set.add(15);
        
        Iterator<Integer> it = set.iterator();
        while(it.hasNext()) {
            System.out.println(it.next());
        }
        Person p1 = new Person(21, "Xia Chen");
        Person p2 = new Person(11, "Li Ying");
        Person p3 = new Person(9, "Zhou Ping");
        Person p4 = new Person(31, "Xu Rui");
        Person p5 = new Person(21, "Li fan");
        
        Set<Person> set = new TreeSet<Person>(new Person());
        set.add(p1);
        set.add(p2);
        set.add(p3);
        set.add(p4);
        set.add(p5);
        System.out.println(set.size());
        
        for(Person p: set) {
            System.out.println(p.name + " " + p.age);
        }
    }
}


class Person implements Comparator<Person>{//将Person存到TreeSet，并且按照age排序
    public int age;
    public String name;
    
    public Person() {}
    
    public Person(int age, String name) {
        this.age = age;
        this.name = name;
    }
    
    //自定义排序
    public int compare(Person x1, Person x2) {
        if (x1.age >= x2.age) {
            return 1;
        }else{
            return -1;
        }    
    }
    
}