BeanComparator实现ArrayList中的元素按多个属性复合排序

import java.util.Collections;      

import java.util.Comparator;      

import java.util.ArrayList;      

import org.apache.commons.beanutils.BeanComparator;      

import org.apache.commons.collections.ComparatorUtils;      

import org.apache.commons.collections.comparators.ComparableComparator;      

import org.apache.commons.collections.comparators.ComparatorChain;      

public class CompareTipA  {      

    private int  id;      

    private String  name;      

    private String age;      

    @SuppressWarnings("unchecked")  

    public static void main(String []args) {      

        //在列表中加入若干CompareTipA对象  

        ArrayList<Object> list = new ArrayList<Object>();      

        list.add(new CompareTipA(1,"3","五"));      

        list.add(new CompareTipA(1,"1","六"));      

        list.add(new CompareTipA(1,"5","二"));      

        list.add(new CompareTipA(1,"4","四"));      

        list.add(new CompareTipA(4,"2","一"));      

        //创建一个排序规则  

        Comparator mycmp = ComparableComparator.getInstance();      

        mycmp = ComparatorUtils.nullLowComparator(mycmp);  //允许null         

        mycmp = ComparatorUtils.reversedComparator(mycmp); //逆序         

        //声明要排序的对象的属性，并指明所使用的排序规则，如果不指明，则用默认排序  

        ArrayList<Object> sortFields = new ArrayList<Object>();      

        sortFields.add(new BeanComparator("id", mycmp)); //id逆序  (主)      

        sortFields.add(new BeanComparator("name"));      //name正序 (副)   

        //创建一个排序链  

        ComparatorChain multiSort = new ComparatorChain(sortFields);   

        //开始真正的排序，按照先主，后副的规则  

        Collections.sort(list,multiSort);      

        for (int i =0;i<list.size();i++) {      

            System.out.println(list.get(i));    //输出      

        }      

        /** 

         * 输出结果如下: 

         * [id=4,name=2,age=一] 

         * [id=1,name=1,age=六] 

         * [id=1,name=3,age=五] 

         * [id=1,name=4,age=四] 

         * [id=1,name=5,age=二] 

         */  

    }      

    public CompareTipA(int id, String name,String age) {      

        this.id = id;      

        this.name = name;      

        this.age = age;      

    }      

    public int getId() {      

        return this.id;      

    }      

    public void setId(int id) {      

        this.id = id;      

    }      

    public String getName() {      

        return this.name;      

    }      

    public void setName(String name) {      

        this.name = name;      

    }      

//    public int compareTo(Object o) {      

//        return this.comparator.compare(this, o);      

//    }      

    public String toString() {      

        return "[id=" + this.id + ",name=" + this.name +",age=" + this.age +"]";      

    }      

    public String getAge() {      

        return age;      

    }      

    public void setAge(String age) {      

        this.age = age;      

    }      

}