java基础入门----TreeMap练习1

import java.util.*;

class TreeMap练习1 
{
	public static void sop(Object obj)
	{
		System.out.println(obj);
	}
	public static void main(String[] args)
	{
		TreeMap<Student0,String> hm = new TreeMap<Student0,String>(new StuNameComparator());
		hm.put(new Student0("aaa",20),"nanjing");
		hm.put(new Student0("bbb",24),"tianjing");
		hm.put(new Student0("ccc",12),"beijing");
		hm.put(new Student0("ccc",22),"beijing");
		hm.put(new Student0("ass",20),"jingdong");

		//第二种取出方式
		Set<Map.Entry<Student0, String>> entrySet = hm.entrySet();
		Iterator<Map.Entry<Student0, String>> iter = entrySet.iterator();
		while(iter.hasNext())
		{
			Map.Entry<Student0, String> me = iter.next();
			Student0 stu = me.getKey();
			String address = me.getValue();
			sop(stu+"......"+address);
		}
	}
}
class Student0 implements Comparable<Student0>
{
	private String name;
	private int age;
	Student0(String name,int age)
	{
		this.name = name;
		this.age = age;
	}
	
	public int hashCode()
	{
		return name.hashCode()+age*34;
	}
	public boolean equals(Object obj)
	{
		if(!(obj instanceof Student0))
			throw new ClassCastException("类型不匹配");
		
		Student0 s = (Student0)obj;
		
		return this.name == s.name && this.age == s.age;
	}
	public int compareTo(Student0 s)
	{
		int num = new Integer(this.age).compareTo(new Integer(s.age));
		if(num == 0)
			return this.name.compareTo(s.name);
		return num;
	}
	
	public String getName()
	{
		return name;
	}
	public int getAge()
	{
		return age;
	}
	public String toString()   //自定义学生类的输出方式，不然就  集合[email protected].
	{
		return name+"==="+age;
	}
}

class StuNameComparator implements Comparator<Student0>
{
	public int compare(Student0 s1,Student0 s2)
	{
		int num = s1.getName().compareTo(s2.getName());
		if(num==0)
			return new Integer(s1.getAge()).compareTo(new Integer(s2.getAge()));
		return num;
	}
}