TreeSet使用匿名内部类创建比较器添加元素

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


public class Test2
{
    public static void main(String[] args)
    {    
        TreeSet<Person> set = new TreeSet<>(new Comparator<Person>() {

            @Override
            public int compare(Person o1, Person o2)
            {
                int  result;
                result = o1.getAge()-o2.getAge();
                if(result==0) {
                    result = o1.getName().compareTo(o2.getName());
                }
                return result;
            }
        });
       Person p1 = new Person("剑魔",20);
       Person p2 = new Person("剑姬",20);
       Person p3 = new Person("剑豪",20);
       Person p4 = new Person("剑圣",20);
       set.add(p1);
       set.add(p2);
       set.add(p3);
       set.add(p4);
     Iterator<Person> iterator = set.iterator();
     while(iterator.hasNext()) {
         System.out.println(iterator.next());
     }
    }
}

自定义一个类

public class Person
{
    private String name;
    private int age;
    public String getName()
    {
        return name;
    }
    public void setName(String name)
    {
        this.name = name;
    }
    public int getAge()
    {
        return age;
    }
    public void setAge(int age)
    {
        this.age = age;
    }
    public Person(String name, int age)
    {
        super();
        this.name = name;
        this.age = age;
    }
    public Person()
    {
        super();
    }
    @Override
    public String toString()
    {
        return "Person [name=" + name + ", age=" + age + "]";
    }
    @Override
    public int hashCode()
    {
        final int prime = 31;
        int result = 1;
        result = prime * result + age;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        return result;
    }
    @Override
    public boolean equals(Object obj)
    {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Person other = (Person) obj;
        if (age != other.age)
            return false;
        if (name == null)
        {
            if (other.name != null)
                return false;
        }
        else if (!name.equals(other.name))
            return false;
        return true;
    }
    
}