[Java] 使用Comparator排序对象

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<Song> songs = new ArrayList<Song>();
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<Song> c){
for(Song song:c){
System.out.println(song);
}
}
}
class SongNameCompare implements Comparator<Song>{

@Override
public int compare(Song o1, Song o2) {
// TODO Auto-generated method stub
return o1.getName().compareTo(o2.getName());
}
}
class SongSongerCompare implements Comparator<Song>{
@Override
public int compare(Song o1, Song o2) {
// TODO Auto-generated method stub
return o1.getSonger().compareTo(o2.getSonger());
}
}
class SongSongIdCompare implements Comparator<Song>{
@Override
public int compare(Song o1, Song o2) {
// TODO Auto-generated method stub
return o1.id>o2.id?1:(o1.id<o2.id?-1:0);
}
}
class Song implements Comparable<Song>{
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<s.id){
return -1;
}else {
return 0;
}

//根据歌名排序
//return this.getName().compareTo(s.getName());
//根据歌手名排序
//return this.getSonger().compareTo(s.getSonger());
}
}