TreeMap demo小样

实现结果：

TreeMapTest实现排序：

package com.xm.hashmap;

import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;

public class TreeMapTest {
    public static void main(String[] args) {
        System.out.println("--------begin------");
        
        Person p1=new Person("马先生","1000");
        Person p2=new Person("李先生","2000");
        Person p3=new Person("王先生","3000");
        
        Map<Number, Person> map=new HashMap<Number,Person>();
        map.put(Integer.parseInt(p1.getAge()), p1);
        map.put(Integer.parseInt(p2.getAge()), p2);
        map.put(Integer.parseInt(p3.getAge()), p3);
        
        System.out.println("HashMap实现的map集合，无顺序");
        for(Iterator<Number> it=map.keySet().iterator();it.hasNext();){
            Person person =map.get(it.next());
            System.out.println(person.getName()+" "+person.getAge());
            
        }
        
        System.out.println("TreeMap实现的map集合，升序");
        Map<Number, Person>  treeMap=new TreeMap<Number ,Person>();
        treeMap.putAll(map);
        for(Iterator it =treeMap.keySet().iterator();it.hasNext();){
            Person person=treeMap.get(it.next());
            System.out.println(person.getName()+" "+person.getAge());
            
        }
        
        System.out.println("TreeMap实现的map集合，降序");
        Map<Number, Person>  treeMap2=new TreeMap<Number ,Person>(Collections.reverseOrder());//初始化为反转排序
        treeMap2.putAll(map);
        for(Iterator it =treeMap2.keySet().iterator();it.hasNext();){//遍历集合
            Person person=treeMap2.get(it.next());
            System.out.println(person.getName()+" "+person.getAge());
            
        }
        
        
        System.out.println("--------end------");
        
        
    
    }
    

}

Person实体：

package com.xm.hashmap;

public class Person {
    String name;
    String age;
    
    public Person(String name,String age) {
        this.name=name;
        this.age=age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAge() {
        return age;
    }
    
    public void setAge(String age) {
        this.age = age;
    }

}