Android移动开发（音乐播放器 BlackMusic）

package com.example.blackmusic.database; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.util.Log; import com.example.blackmusic.entity.MusicInfo; import com.example.blackmusic.entity.PlayListInfo; import com.example.blackmusic.util.ChineseToEnglish; import com.example.blackmusic.util.Constant; import com.example.blackmusic.util.MyMusicUtil; import java.util.ArrayList; import java.util.List; import static com.example.blackmusic.database.DatabaseHelper.ID_COLUMN; import static com.example.blackmusic.database.DatabaseHelper.MUSIC_ID_COLUMN; public class DBManager { private static final String TAG = DBManager.class.getName(); private DatabaseHelper helper; private SQLiteDatabase db; private static DBManager instance = null; /* 因为getWritableDatabase内部调用了mContext.openOrCreateDatabase(mName, 0,mFactory); * 需要一个context参数 ,所以要确保context已初始化,我们可以把实例化DBManager的步骤放在Activity的onCreate里 */ public DBManager(Context context) { helper = new DatabaseHelper(context); db = helper.getWritableDatabase(); } public static synchronized DBManager getInstance(Context context) { if (instance == null) { instance = new DBManager(context); } return instance; } // 获取音乐表歌曲数量 public int getMusicCount(int table) { int musicCount = 0; Cursor cursor = null; switch (table) { case Constant.LIST_ALLMUSIC: cursor = db.query(DatabaseHelper.MUSIC_TABLE, null, null, null, null, null, null); break; case Constant.LIST_LASTPLAY: cursor = db.query(DatabaseHelper.LAST_PLAY_TABLE, null, null, null, null, null, null); break; case Constant.LIST_MYLOVE: cursor = db.query(DatabaseHelper.MUSIC_TABLE, null, DatabaseHelper.LOVE_COLUMN + " = ? ", new String[]{"" + 1}, null, null, null); break; case Constant.LIST_MYPLAY: cursor = db.query(DatabaseHelper.PLAY_LIST_TABLE, null, null, null, null, null, null); break; } if (cursor.moveToFirst()) { musicCount = cursor.getCount(); } if (cursor != null) { cursor.close(); } return musicCount; } public List<MusicInfo> getAllMusicFromMusicTable() { Log.d(TAG, "getAllMusicFromMusicTable: "); List<MusicInfo> musicInfoList = new ArrayList<>(); Cursor cursor = null; db.beginTransaction(); try { cursor = db.query(DatabaseHelper.MUSIC_TABLE, null, null, null, null, null, null); musicInfoList = cursorToMusicList(cursor); db.setTransactionSuccessful(); } catch (Exception e) { e.printStackTrace(); } finally { db.endTransaction(); if (cursor!=null){ cursor.close(); } } return musicInfoList; } public MusicInfo getSingleMusicFromMusicTable(int id) { Log.i(TAG, "getSingleMusicFromMusicTable: "); List<MusicInfo> musicInfoList = null; MusicInfo musicInfo = null; Cursor cursor = null; db.beginTransaction(); try { cursor = db.query(DatabaseHelper.MUSIC_TABLE, null, ID_COLUMN + " = ?", new String[]{"" + id}, null, null, null); musicInfoList = cursorToMusicList(cursor); musicInfo = musicInfoList.get(0); db.setTransactionSuccessful(); } catch (Exception e) { e.printStackTrace(); } finally { db.endTransaction(); if (cursor!=null){ cursor.close(); } } return musicInfo; } public List<MusicInfo> getAllMusicFromTable(int playList) { Log.d(TAG, "getAllMusicFromTable: "); List<Integer> idList = getMusicList(playList); List<MusicInfo> musicList = new ArrayList<>(); for (int id : idList) { musicList.add(getSingleMusicFromMusicTable(id)); } return musicList; } /** * 获取我的歌单列表 * @return */ public List<PlayListInfo> getMyPlayList() { List<PlayListInfo> playListInfos = new ArrayList<>(); Cursor cursor = db.query(DatabaseHelper.PLAY_LIST_TABLE, null, null, null, null, null, null); Cursor cursorCount = null; while (cursor.moveToNext()) { PlayListInfo playListInfo = new PlayListInfo(); int id = Integer.valueOf(cursor.getString(cursor.getColumnIndex(ID_COLUMN))); playListInfo.setId(id); playListInfo.setName(cursor.getString(cursor.getColumnIndex(DatabaseHelper.NAME_COLUMN))); cursorCount = db.query(DatabaseHelper.PLAY_LISY_MUSIC_TABLE,null, ID_COLUMN + " = ?", new String[]{"" + id}, null,null,null); playListInfo.setCount(cursorCount.getCount()); playListInfos.add(playListInfo); } if (cursor!=null){ cursor.close(); } if (cursorCount!=null){ cursorCount.close(); } return playListInfos; } public void createPlaylist(String name) { ContentValues values = new ContentValues(); values.put(DatabaseHelper.NAME_COLUMN, name); db.insert(DatabaseHelper.PLAY_LIST_TABLE, null, values); } public List<MusicInfo> getMusicListBySinger(String singer){ List<MusicInfo> musicInfoList = new ArrayList<>(); Cursor cursor = null; db.beginTransaction(); try{ String sql = "select * from "+DatabaseHelper.MUSIC_TABLE+" where "+ DatabaseHelper.SINGER_COLUMN+" = ? "; cursor = db.rawQuery(sql,new String[]{singer}); musicInfoList = cursorToMusicList(cursor); db.setTransactionSuccessful(); }catch (Exception e){ e.printStackTrace(); }finally { db.endTransaction(); if (cursor !=null) cursor.close(); } return musicInfoList; } public List<MusicInfo> getMusicListByAlbum(String album){ List<MusicInfo> musicInfoList = new ArrayList<>(); Cursor cursor = null; db.beginTransaction(); try{ String sql = "select * from "+DatabaseHelper.MUSIC_TABLE+" where "+ DatabaseHelper.ALBUM_COLUMN+" = ? "; cursor = db.rawQuery(sql,new String[]{album}); musicInfoList = cursorToMusicList(cursor); db.setTransactionSuccessful(); }catch (Exception e){ e.printStackTrace(); }finally { db.endTransaction(); if (cursor !=null) cursor.close(); } return musicInfoList; } public List<MusicInfo> getMusicListByFolder(String folder){ List<MusicInfo> musicInfoList = new ArrayList<>(); Cursor cursor = null; db.beginTransaction(); try{ String sql = "select * from "+DatabaseHelper.MUSIC_TABLE+" where "+ DatabaseHelper.PARENT_PATH_COLUMN+" = ? "; cursor = db.rawQuery(sql,new String[]{folder}); musicInfoList = cursorToMusicList(cursor); db.setTransactionSuccessful(); }catch (Exception e){ e.printStackTrace(); }finally { db.endTransaction(); if (cursor !=null) cursor.close(); } return musicInfoList; } public ArrayList<Integer> getMusicIdListByPlaylist(int playlistId){ Cursor cursor = null; db.beginTransaction(); ArrayList<Integer> list = new ArrayList<Integer>(); try{ String sql = "select * from "+DatabaseHelper.PLAY_LISY_MUSIC_TABLE+" wher