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NewsItem.jar package collection.sort.newsitemsort; import java.text.SimpleDateFormat; import java.util.Date; /** * 新闻条目实体类 */ public class NewsItem implements Comparable<NewsItem>{ //标题 private String title; //点击量 private int hits; //时间 private Date pubTime; public NewsItem() { } public NewsItem(String title, int hits, Date pubTime) { super(); this.title = title; this.hits = hits; this.pubTime = pubTime; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public int getHits() { return hits; } public void setHits(int hits) { this.hits = hits; } public Date getPubTime() { return pubTime; } public void setPubTime(Date pubTime) { this.pubTime = pubTime; } //时间降序 +点击量升序+标题降序 @Override public int compareTo(NewsItem o) { int result =0; //比较 时间 result =-this.pubTime.compareTo(o.pubTime); //降序 if(0==result){ //时间相同 //点击量 result =this.hits-o.hits; //升序 if(0==result){ //点击量相同 //标题 result=-this.title.compareTo(o.title);//降序 } } return result; } @Override public String toString() { StringBuilder sb =new StringBuilder(); sb.append("标题:").append(this.title); sb.append(",时间:").append(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(this.pubTime)); sb.append(",点击量:").append(this.hits).append("\n"); return sb.toString(); } } NewsItemImpl.jar package collection.sort.newsitemsort; import java.util.ArrayList; import java.util.Collections; import java.util.Date; import java.util.List; /** * 使用Collections */ public class NewsItemImpl { public static void main(String[] args) { List<NewsItem> news=new ArrayList<NewsItem>(); news.add(new NewsItem("美国后怕了，逃跑了悲剧了",50,new Date(System.currentTimeMillis()-1000*60*60))); news.add(new NewsItem("中国登上钓鱼岛了，全国欢呼了",100,new Date())); news.add(new NewsItem("小日本终于听话了，泪流满面笑了",60,new Date(System.currentTimeMillis()-1000*60*60))); System.out.println("排序前:"+news); //排序 Collections.sort(news); System.out.println("排序后"+news); } } Goods.jar package collection.sort.newsitemsort; public class Goods { //商品名称 private String name; //价格 private double price; //收藏量 private int fav; public Goods() { } public Goods(String name, double price, int fav) { super(); this.name = name; this.price = price; this.fav = fav; } public String getName() { return name; } public void setName(String name) { this.name = name; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; } public int getFav() { return fav; } public void setFav(int fav) { this.fav = fav; } @Override public String toString() { return "商品名:"+name+",收藏量"+this.fav+",价格:"+this.price+"\n"; } } GoodsImpl.java package collection.sort.newsitemsort; import java.util.ArrayList; import java.util.Collections; import java.util.List; public class GoodsImpl { public static void main(String[] args) { List<Goods> list =new ArrayList<Goods>(); list.add(new Goods("老马视频",100,2000)); list.add(new Goods("老高视频",50,2000)); list.add(new Goods("老裴视频",1000,1000)); System.out.println("排序前:"+list); // Collections.sort(list,new GoodsPriceComp()); Collections.sort(list,new GoodsFavCompare()); System.out.println("排序后:"+list); } } GoodsPriceCompare.java package collection.sort.newsitemsort; import java.util.Comparator; /** * 实现Comparable接口，提高比较的条件 * 按价格排序的业务类 （降序） */ public class GoodsPriceCompare implements Comparator<Goods> { @Override public int compare(Goods o1, Goods o2) { return -(o1.getPrice()-o2.getPrice()>0?1:(o1.getPrice()==o2.getPrice()?0:-1)); } } GoodsFavCompare.java package collection.sort.newsitemsort; import java.util.Comparator; /** * 按收藏量排序的业务类 （升序） */ public class GoodsFavCompare implements Comparator<Goods>{ @Override public int compare(Goods o1, Goods o2) { return o1.getFav()-o2.getFav(); } }