comparatable and comparator

package com.zhoubo.concurrent.collection;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
 * 通过实现comparable来实现对对象的排序。
 * @author Administrator
 *
 */
public class OrderList2 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		List list = new ArrayList();
		list.add(new B(1));
		list.add(new B(4));
		list.add(new B(2));
		list.add(new B(3));
		list.add(new B(3));
		//排序之前的顺序
		System.out.println(list);
		Collections.sort(list);
		//排序之后的顺序
		System.out.println(list);

	}

}

class A {
	public int i = 0;
	public A(int ii) {
		this.i = ii;
	}
	
	@Override
	public String toString() {
		return i+"";
	}
}

class B extends A implements Comparable{
	public B(int ii){
		super(ii);
	}
	
	@Override
	public int compareTo(Object arg0) {
		if(this.i > ((A)arg0).i)
			return 1;
		else if(this.i == ((A)arg0).i)
			return 0;
		else
			return -1;
	}
}

 

package com.zhoubo.concurrent.collection;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
/**
 * 对list中的对象排序,使用comparator
 * @author Administrator
 *
 */
public class OrderList {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		List list = new ArrayList();
		list.add(new Aobject(1));
		list.add(new Aobject(4));
		list.add(new Aobject(2));
		list.add(new Aobject(3));
		list.add(new Aobject(3));
		System.out.println(list);
		Collections.sort(list,new Acomparator());
		System.out.println(list);
	}	

}
class Aobject {
	public int i = 0;
	public Aobject(int ii) {
		this.i = ii;
	}
	
	@Override
	public String toString() {
		return i+"";
	}
}

class Acomparator implements Comparator{
	@Override
	public int compare(Object arg0, Object arg1) {
		if(((Aobject)arg0).i >((Aobject)arg1).i){
			return 1;
		}else if(((Aobject)arg0).i ==((Aobject)arg1).i){
			return 0;
		}else
			return -1;
	}
	
}