[Java] 使用Comparator排序对象-白红宇

[Java] 使用Comparator排序对象

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发布时间：2019-06-13

本文共 2265 字，大约阅读时间需要 7 分钟。

package test.collections;import java.util.ArrayList;import java.util.Collection;import java.util.Collections;import java.util.Comparator;import java.util.List;public class Test03 {    public static void main(String[] args){        List
     
       songs = new ArrayList
      
       ();        songs.add(new Song(2,"黄家驹","光辉岁月"));        songs.add(new Song(5,"刘德华","忘情水"));        songs.add(new Song(44,"张学友","吻别"));        songs.add(new Song(32,"刘德华","爱你一万年"));        songs.add(new Song(123,"黄家驹","冷雨夜"));        songs.add(new Song(133,"小虎队","爱"));                //Collections.sort(songs);        //Collections.sort(songs,new SongNameCompare());        //Collections.sort(songs,new SongSongerCompare());        Collections.sort(songs,new SongSongIdCompare());        printList(songs);    }    public static void printList(Collection
       
         c){        for(Song song:c){            System.out.println(song);        }    }}class SongNameCompare implements Comparator
        
         {    @Override    public int compare(Song o1, Song o2) {        // TODO Auto-generated method stub        return o1.getName().compareTo(o2.getName());    }}class SongSongerCompare implements Comparator
         
          {    @Override    public int compare(Song o1, Song o2) {        // TODO Auto-generated method stub        return o1.getSonger().compareTo(o2.getSonger());    }}class SongSongIdCompare implements Comparator
          
           { @Override public int compare(Song o1, Song o2) { // TODO Auto-generated method stub return o1.id>o2.id?1:(o1.id
           
            { private String name; private String songer; int id; public Song(int id,String songer,String name) { super(); this.id = id; this.name = name; this.songer = songer; } @Override public String toString() { return "Song [name=" + name + ", songer=" + songer + ", id=" + id + "]"; } public Song() { super(); } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSonger() { return songer; } public void setSonger(String songer) { this.songer = songer; } public int compareTo(Song s){ //使用this.id 和s.id做比较，如果返回值>1,表示顺序排序，返回值是<1的数表示倒序 if(this.id>s.id){ return 1; }else if(this.id