比起Comparable介面比較器Comparator為我們在排序中提供了更寬鬆和更加廣泛的應用例項：在實際中，常常需要對一個商品按照不同屬性來排序，這時我們就能通過寫出自己的Comparator來實現不同的排序方式

public class Goods{
	private int goodsId;		//編號
	private String goodsName;	//品名
	private double goodsOriginalPrice;	//原價
	private double goodsSellPrice;	//賣價
	private int goodsInStock;	//庫存
	private ArrayList<String> goodsShowPics;	//展示圖集合url
	private ArrayList<String> goodsDetailPics;	//商品圖集合url
	private String goodsProducer;	//生產者
	private String goodsProducePlace;	//產地
	private Timestamp goodsInDate;	//入庫時間
	private String goodsPackage;	//包裝內容
	private String goodsCM;		//產品規格
	private String goodsService;	//售後服務
	private int goodsViewed;	//商品瀏覽量
	private int goodsSold; 	//商品銷售量
	private double goodsPoint;		//商品評分
	public Goods(){	
	}
}

這時如果在類Goods中插入靜態內部final Comparator類就可以實現

使用靜態內部final類好處在於呼叫時候結構清晰，呼叫方便，並且無需重複例項化比較器物件，節省了系統開支

在Goods類中插入如下程式碼：

/**
	 * 靜態內部類比較按入庫時間		//降序	
	 */
	public static final Comparator<Goods> GOODS_BY_INDATE = new Comparator<Goods>(){		
		public int compare(Goods o1, Goods o2) {
			return o2.getGoodsInDate().compareTo(o1.getGoodsInDate());
		}
	};
	/**
	 * 靜態內部類比較按售價
	 */
	public static final Comparator<Goods> GOODS_BY_SELLPRICE = new Comparator<Goods>() {
		public int compare(Goods o1, Goods o2) {
			return (int) (o1.getGoodsSellPrice()-o2.getGoodsSellPrice());
		}
	};
	/**
	 * 靜態內部類比較按售價			//降序
	 */
	public static final Comparator<Goods> GOODS_BY_SELLPRICE_DESC = new Comparator<Goods>() {
		public int compare(Goods o1, Goods o2) {
			return (int) (o2.getGoodsSellPrice()-o1.getGoodsSellPrice());
		}
	};
	/**
	 * 靜態內部類比較按點選量			//降序
	 */
	public static final Comparator<Goods> GOODS_BY_GOODSVIEWD = new Comparator<Goods>() {
		public int compare(Goods o1, Goods o2) {
			// TODO Auto-generated method stub
			return o2.getGoodsViewed()-o1.getGoodsViewed();
		}
	};
	/**
	 * 靜態內部類按銷量排序			//降序
	 */
	public static final Comparator<Goods> GOODS_BY_GOODSSOLD = new Comparator<Goods>() {
		public int compare(Goods o1, Goods o2) {
			return o2.getGoodsSold()-o1.getGoodsSold();
		}
	};
	/**
	 * 靜態內部類按評分排序			//降序
	 */
	public static final Comparator<Goods> GOODS_BY_POINT = new Comparator<Goods>() {		
		public int compare(Goods o1, Goods o2) {
			return (int) (o2.getGoodsPoint()-o1.getGoodsPoint());
		}
	};
 

例如，對於已經存在的名為showResult的Goods集合用下面的程式碼就可以實現排序了：

if(sortType.equals("bySold")){				//按銷量時候
			Collections.sort(showResult, Goods.GOODS_BY_GOODSSOLD);
		}
		if(sortType.equals("byViewed")){			//按點選量時候
			Collections.sort(showResult, Goods.GOODS_BY_GOODSVIEWD);
		}
		if(sortType.equals("byInDate")){			//按入庫時間時候
			Collections.sort(showResult, Goods.GOODS_BY_INDATE);
		}
		if(sortType.equals("byPoint")){				//按評分時候
			Collections.sort(showResult, Goods.GOODS_BY_POINT);
		}
		if(sortType.equals("byPrice")){				//按價格時候
			Collections.sort(showResult, Goods.GOODS_BY_SELLPRICE);
		}
		if(sortType.equals("byPriceDown")){			//按價格降序時候
			Collections.sort(showResult, Goods.GOODS_BY_SELLPRICE_DESC);
		}