Set里面的方法

HasSet让元素有按照hash排序
LinkSet让元素的顺序按照输入顺序排列
Treeset让元素可以排序可以实现Comparator接口实现对象的对比或者自己在类里面实现comparable接口的方法
package test;


import java.util.*;

import javax.imageio.event.IIOReadWarningListener;
import javax.security.auth.kerberos.KerberosKey;

import privateclass.*;

import java.io.*;
import java.math.BigInteger;


class lop
{
	public void te()
	{
		System.out.println("yey");
	}
}
 
class Animal extends lop
{
	int num = 4;
	public void eat()
	{
		
	}
}

class Dog extends Animal
{
	
	int num = 5;
}


interface kk
{
	public void wo();
}

interface dd
{
	public void wo();
}

class poue implements kk,dd{

	@Override
	public void wo() {
		// TODO Auto-generated method stub
		
	}
	
}
public class Main {

	private static final String space_operator = " ";
	public static void main(String[] args) throws Exception {

		Scanner scanner = new Scanner(new BufferedInputStream(System.in));
		PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
		
		TreeSet has = new TreeSet(new ComparaorName());
		
		has.add(new Person("zhangsan1",21));
		has.add(new Person("zhangsan2",31));
		has.add(new Person("zhangsan3",41));
		has.add(new Person("lhangsan4",51));
		has.add(new Person("zhangsan1",11));
		
		for(Iterator it = has.iterator(); it.hasNext();)
		{
			Object object = it.next();
			System.out.println(object.toString());
		}
		
	}
}


package privateclass;

public class Person implements Comparable{

	private String naem;
	private int age;

	public String getNaem() {
		return naem;
	}

	public void setNaem(String naem) {
		this.naem = naem;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

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

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + age;
		result = prime * result + ((naem == null) ? 0 : naem.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 (naem == null) {
			if (other.naem != null)
				return false;
		} else if (!naem.equals(other.naem))
			return false;
		return true;
	}

	public Person() {
		super();
	}

	@Override
	public String toString() {
		return "Person [naem=" + naem + ", age=" + age + "]";
	}

	@Override
	public int compareTo(Object o) {
		Person p = (Person) o;
		int temp = this.age - p.age;
		return temp == 0 ? this.naem.compareTo(p.naem) : temp;
	}

}




package privateclass;

import java.util.Comparator;

public class ComparaorName implements Comparator {

	@Override
	public int compare(Object o1, Object o2) {
		Person p1 = (Person) o1;
		Person p2 = (Person) o2;
		int temp = p1.getNaem().compareTo(p2.getNaem());
		return temp == 0 ? p1.getAge() - p2.getAge() : temp;
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub

	}

}