package com.jabberchina.test;  

import java.util.ArrayList;

import java.util.Collections;

import java.util.Comparator;

import java.util.List;  

public class SortTest {  

    public static void main(String[] args) {

        List<String> lists = new ArrayList<String>();

        List<A> list = new ArrayList<A>();

        List<B> listB = new ArrayList<B>();

        lists.add("5");

        lists.add("2");

        lists.add("9");

        //lists中的对象String 本身含有compareTo方法，所以可以直接调用sort方法，按自然顺序排序，即升序排序

        Collections.sort(lists);  

        A aa = new A();

        aa.setName("aa");

        aa.setOrder(1);

        A bb = new A();

        bb.setName("bb");

        bb.setOrder(2);

        list.add(bb);

        list.add(aa);

        //list中的对象A实现Comparable接口

        Collections.sort(list);  

        B ab = new B();

        ab.setName("ab");

        ab.setOrder("1");

        B ba = new B();

        ba.setName("ba");

        ba.setOrder("2");

        listB.add(ba);

        listB.add(ab);

        //根据Collections.sort重载方法来实现

        Collections.sort(listB,new Comparator<B>(){

            @Override

            public int compare(B b1, B b2) {

                return b1.getOrder().compareTo(b2.getOrder());

            }  

        });  

        System.out.println(lists);

        System.out.println(list);

        System.out.println(listB);  

    }  

}  

class A implements Comparable<A>{

    private String name;

    private Integer order;

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }  

    public Integer getOrder() {

        return order;

    }

    public void setOrder(Integer order) {

        this.order = order;

    }

    @Override

    public String toString() {

        return "name is "+name+" order is "+order;

    }

    @Override

    public int compareTo(A a) {

        return this.order.compareTo(a.getOrder());

    }  

}  

class B{

    private String name;

    private String order;

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getOrder() {

        return order;

    }

    public void setOrder(String order) {

        this.order = order;

    }

    @Override

    public String toString() {

        return "name is "+name+" order is "+order;

    }

}  

打印的结果为：

 [2, 5, 9]

[name is aa order is 1, name is bb order is 2]

[name is ab order is 1, name is ba order is 2]