怎么封装list map集合类型，封装了怎么添加数据和怎么设置泛型，封装以后怎样对数据进行增删改查。

public class PlayList {

private String playListName;//播放器列表名称

// private ArrayList musicList;//播放器列表里面歌曲

List<Song> list=new ArrayList<Song>();

public PlayList(){//无参的构造方法

}

public PlayList(String playListName){//带参的构造方法,ArrayList musicList

this.playListName=playListName;

//this.musicList=musicList;

}

//set/get方法

public String getPlayListName() {

return playListName;

}

public void setPlayListName(String playListName) {

this.playListName = playListName;

}

// public ArrayList getMusicList() {

// return musicList;

// }

// public void setMusicList(ArrayList musicList) {

// this.musicList = musicList;

// }

//  

//将歌曲添加到播放列表

public void addToPlayList(Song song){

list.add(song);

}

//显示播放列表中所有的歌曲

public void displayAllSong(){

Iterator<Song> it=list.iterator();

while(it.hasNext()){

Song song=it.next();

song.toString();

}

}

//通过ID查询歌曲

public void searchSongById(String id){

Iterator<Song> it=list.iterator();

while(it.hasNext()){

Song song=it.next();

if(id.equals(song.getId())){

System.out.println("有该歌曲");

song.toString();

}

}

} 

//通过歌曲名查询歌曲

public void searchSongByName(String name){

Iterator<Song> it=list.iterator();

while(it.hasNext()){

Song song=it.next();

if(name.equals(song.getName())){

System.out.println("有该歌曲");

song.toString();

}

}

}

//修改歌曲

public void updateSong(int in,Song song){

list.set(in, song);

}

//删除歌曲

public void deleteSong(String id){

Iterator<Song> it=list.iterator();

while(it.hasNext()){

Song song=it.next();

if(id.equals(song.getId())){

list.remove(song);

System.out.println("以删除该歌曲");

}

}

}

}

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public class PlayListCollection {

private Map playListMap;//存放播放器列表的集合

Scanner in=new Scanner(System.in);

// Map<String ,PlayList> map=new HashMap<String ,PlayList>();

public PlayListCollection(){//带参的构造方法

}

public PlayListCollection(Map playListMap){//带参的构造方法

this.playListMap=playListMap;

}

// set/get方法

public Map getPlayListMap() {

return playListMap;

}

public void setPlayListMap(Map playListMap) {

this.playListMap = playListMap;

}

//添加播放列表

public void addPlayList(String playList){

PlayListCollection plc=new PlayListCollection();

new PlayList().setPlayListName("主播放列表");

plc.setPlayListMap(playListMap);

}

//删除播放列表

public void deletePlayList(PlayList playList){

}

//通过名字查询

public PlayList searchPlayListByName(String PlayListName){

return null;

}

//显示所有播放列表名称

public void displayListName(){

}

}

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