package com.bo.collection;

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

//TreeSet 儲存結構 紅黑樹  要實現comparable介面 不然有得資料新增不進去
//如果compareTo()方法的返回值為0，則認為是重複元素
//在person實現了
public class Demo11 {
    public static void main(String[] args) {
        //建立集合
        TreeSet<String> treeSet =new TreeSet<>();
        //新增
        treeSet.add("abc");
        treeSet.add("def");
        treeSet.add("ghi");
        System.out.println("元素個數："+treeSet.size());
        System.out.println(treeSet.toString());
        //刪除
        treeSet.remove("abc");
        System.out.println("刪除後元素個數："+treeSet.size());
        //遍歷
        System.out.println("------增強for------");
        for (String s : treeSet) {
            System.out.println(s);
        }
        System.out.println("------迭代器------");
        Iterator it= treeSet.iterator();
        while(it.hasNext()){
            System.out.println(it.next());
        }
        System.out.println(treeSet.contains("def"));
        System.out.println("=====================================");
        TreeSet<Person> pts =new TreeSet<>();
        Person p1=new Person("張學友",23);
        Person p2=new Person("劉德華",24);
        Person p3=new Person("郭富城",24);
        Person p4=new Person("張學友",22);
        pts.add(p1);
        pts.add(p2);
        pts.add(p3);
        pts.add(p4);
        System.out.println("元素個數"+pts.size());//
        //ClassCastException: com.bo.collection.Person cannot be cast to java.lang.Comparable
        //異常 不能把person轉成comparable 紅黑樹不知道比什麼 要重寫比較方法
        System.out.println(pts.toString());
    }
}

package com.bo.collection;



public class Person implements Comparable<Person> {
    private String name;
    private int age;

    public Person() {
    }

    public Person(String name, int age) {
        this.name = name;
        this.age = 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;
    }

    @Override
    public String toString() {
        return "Person{" + "name=" + name  + ", age=" + age + '}';
    }



    public int hashCode() {
       int n1 = this.name.hashCode();
       int n2 = this.age;
       return n1+n2;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null ) return false;
        if (o instanceof Person){
        Person p = (Person) o;
            if (this.name.equals(p.getName())&&this.age== p.getAge());
            return true;
        }
        return false;
    }

   // @Override
    //public int compareTo(Object o) {

      //  if (o instanceof Person){
      //      Person p=(Person) o;
      //      int n1 = this.getName().compareTo(p.getName());
      //      int n2 = this.age-p.getAge();
       //     return n1==0?n2:n1;
      //  }
      //  return 0;
   // }

    @Override//上面那個沒有用泛型 這個沒有重寫
    public int compareTo(Person o) {
        return 0;
    }
}