Android仿虾米音乐播放器之本地音乐获取
2015-07-15 17:59
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Android系统为了一些常用的信息(如音乐、视频、图像、联系人等)内置了一系列的ContentProvider,所以我们可以通过这个来获取Anroid中本地音乐,首先得加入权限
如果想要修改甚至删除数据,还要加上写的权限
为了实例化mp3音乐,我们首先定义一个mp3info的bean,里面给出所需要的属性,比如id,title,album等等,另外为了使其能在activity与service中进行通信传值,需要序列化,android中序列化一般使用Parcelable,用法可以参考 点击打开链接
mp3info.java
获取本地音乐及其专辑图片的代码,部分参考他人代码, MediaUtil.java
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
如果想要修改甚至删除数据,还要加上写的权限
为了实例化mp3音乐,我们首先定义一个mp3info的bean,里面给出所需要的属性,比如id,title,album等等,另外为了使其能在activity与service中进行通信传值,需要序列化,android中序列化一般使用Parcelable,用法可以参考 点击打开链接
mp3info.java
public class Mp3Info implements Parcelable{ private long id; private String title; private String artist; private String album; private long albumId; private long duration; private long size; private String url; public Mp3Info(){ } public Mp3Info(Parcel parcel){ id = parcel.readLong(); title = parcel.readString(); artist = parcel.readString(); album = parcel.readString(); albumId = parcel.readLong(); duration = parcel.readLong(); size = parcel.readLong(); url = parcel.readString(); } public long getId() { return id; } public void setId(long id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getArtist() { return artist; } public void setArtist(String artist) { this.artist = artist; } public String getAlbum() { return album; } public void setAlbum(String album) { this.album = album; } public long getAlbumId() { return albumId; } public void setAlbumId(long albumId) { this.albumId = albumId; } public long getDuration() { return duration; } public void setDuration(long duration) { this.duration = duration; } public long getSize() { return size; } public void setSize(long size) { this.size = size; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } @Override public int describeContents() { return 0; } @Override public void writeToParcel(Parcel dest, int flags) { dest.writeLong(id); dest.writeString(title); dest.writeString(artist); dest.writeString(album); dest.writeLong(albumId); dest.writeLong(duration); dest.writeLong(size); dest.writeString(url); } public static final Parcelable.Creator<Mp3Info> CREATOR = new Creator<Mp3Info>() { @Override public Mp3Info[] newArray(int size) { return new Mp3Info[size]; } @Override public Mp3Info createFromParcel(Parcel source) { return new Mp3Info(source); } }; }
获取本地音乐及其专辑图片的代码,部分参考他人代码, MediaUtil.java
// 获取专辑封面的Uri private static final Uri albumArtUri = Uri .parse("content://media/external/audio/albumart"); /** * 用于从数据库中查询歌曲的信息,保存在List当中 * * @return */ public static List<Mp3Info> getMp3Infos(Context context) { Cursor cursor = context.getContentResolver().query( MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, null, null, MediaStore.Audio.Media .DEFAULT_SORT_ORDER); List<Mp3Info> mp3Infos = new ArrayList<Mp3Info>(); for (int i = 0; i < cursor.getCount(); i++) { cursor.moveToNext(); Mp3Info mp3Info = new Mp3Info(); long id = cursor.getLong(cursor .getColumnIndex(MediaStore.Audio.Media._ID)); // 音乐id String title = cursor.getString((cursor .getColumnIndex(MediaStore.Audio.Media.TITLE))); // 音乐标题 String artist = cursor.getString(cursor .getColumnIndex(MediaStore.Audio.Media.ARTIST)); // 艺术家 String album = cursor.getString(cursor .getColumnIndex(MediaStore.Audio.Media.ALBUM)); // 专辑 long albumId = cursor.getInt(cursor .getColumnIndex(MediaStore.Audio.Media.ALBUM_ID)); long duration = cursor.getLong(cursor .getColumnIndex(MediaStore.Audio.Media.DURATION)); // 时长 long size = cursor.getLong(cursor .getColumnIndex(MediaStore.Audio.Media.SIZE)); // 文件大小 String url = cursor.getString(cursor .getColumnIndex(MediaStore.Audio.Media.DATA)); // 文件路径 int isMusic = cursor.getInt(cursor .getColumnIndex(MediaStore.Audio.Media.IS_MUSIC)); // 是否为音乐 if (isMusic != 0) { // 只把音乐添加到集合当中 mp3Info.setId(id); mp3Info.setTitle(title); mp3Info.setArtist(artist); mp3Info.setAlbum(album); mp3Info.setAlbumId(albumId); mp3Info.setDuration(duration); mp3Info.setSize(size); mp3Info.setUrl(url); mp3Infos.add(mp3Info); } } cursor.close(); return mp3Infos; } /** * 格式化时间,将毫秒转换为分:秒格式 * * @param time * @return */ public static String formatTime(long time) { String min = time / (1000 * 60) + ""; String sec = time % (1000 * 60) + ""; if (min.length() < 2) { min = "0" + time / (1000 * 60) + ""; } else { min = time / (1000 * 60) + ""; } if (sec.length() == 4) { sec = "0" + (time % (1000 * 60)) + ""; } else if (sec.length() == 3) { sec = "00" + (time % (1000 * 60)) + ""; } else if (sec.length() == 2) { sec = "000" + (time % (1000 * 60)) + ""; } else if (sec.length() == 1) { sec = "0000" + (time % (1000 * 60)) + ""; } return min + ":" + sec.trim().substring(0, 2); } /** * 获取默认专辑图片 * * @param context * @return */ public static Bitmap getDefaultArtwork(Context context, boolean small) { BitmapFactory.Options opts = new BitmapFactory.Options(); opts.inPreferredConfig = Bitmap.Config.RGB_565; if (small) { // 返回小图片,文件路径为默认的图片 return BitmapFactory.decodeStream(context.getResources() .openRawResource(R.drawable.default_cover_64), null, opts); } return BitmapFactory.decodeStream(context.getResources() .openRawResource(R.drawable.default_cover_640), null, opts); } /** * 从文件当中获取专辑封面位图 * * @param context * @param songid * @param albumid * @return */ private static Bitmap getArtworkFromFile(Context context, long songid, long albumid) { Bitmap bm = null; if (albumid < 0 && songid < 0) { throw new IllegalArgumentException( "Must specify an album or a song id"); } try { BitmapFactory.Options options = new BitmapFactory.Options(); FileDescriptor fd = null; if (albumid < 0) { Uri uri = Uri.parse("content://media/external/audio/media/" + songid + "/albumart"); ParcelFileDescriptor pfd = context.getContentResolver() .openFileDescriptor(uri, "r"); if (pfd != null) { fd = pfd.getFileDescriptor(); } } else { Uri uri = ContentUris.withAppendedId(albumArtUri, albumid); ParcelFileDescriptor pfd = context.getContentResolver() .openFileDescriptor(uri, "r"); if (pfd != null) { fd = pfd.getFileDescriptor(); } } options.inSampleSize = 1; // 只进行大小判断 options.inJustDecodeBounds = true; // 调用此方法得到options得到图片大小 BitmapFactory.decodeFileDescriptor(fd, null, options); // 我们的目标是在800pixel的画面上显示 // 所以需要调用computeSampleSize得到图片缩放的比例 options.inSampleSize = 100; // 我们得到了缩放的比例,现在开始正式读入Bitmap数据 options.inJustDecodeBounds = false; options.inDither = false; options.inPreferredConfig = Bitmap.Config.ARGB_8888; // 根据options参数,减少所需要的内存 bm = BitmapFactory.decodeFileDescriptor(fd, null, options); } catch (FileNotFoundException e) { e.printStackTrace(); } return bm; } /** * 获取专辑封面位图对象 * * @param context * @param song_id * @param album_id * @param allowdefalut * @return */ public static Bitmap getArtwork(Context context, long song_id, long album_id, boolean allowdefalut, boolean small) { if (album_id < 0) { if (song_id < 0) { Bitmap bm = getArtworkFromFile(context, song_id, -1); if (bm != null) { return bm; } } if (allowdefalut) { return getDefaultArtwork(context, small); } return null; } ContentResolver res = context.getContentResolver(); Uri uri = ContentUris.withAppendedId(albumArtUri, album_id); if (uri != null) { InputStream in = null; try { in = res.openInputStream(uri); BitmapFactory.Options options = new BitmapFactory.Options(); // 先制定原始大小 options.inSampleSize = 1; // 只进行大小判断 options.inJustDecodeBounds = true; // 调用此方法得到options得到图片的大小 BitmapFactory.decodeStream(in, null, options); /** 我们的目标是在你N pixel的画面上显示。 所以需要调用computeSampleSize得到图片缩放的比例 **/ /** 这里的target为800是根据默认专辑图片大小决定的,800只是测试数字但是试验后发现完美的结合 **/ if (small) { options.inSampleSize = computeSampleSize(options, 40); } else { options.inSampleSize = computeSampleSize(options, 600); } // 我们得到了缩放比例,现在开始正式读入Bitmap数据 options.inJustDecodeBounds = false; options.inDither = false; options.inPreferredConfig = Bitmap.Config.ARGB_8888; in = res.openInputStream(uri); return BitmapFactory.decodeStream(in, null, options); } catch (FileNotFoundException e) { Bitmap bm = getArtworkFromFile(context, song_id, album_id); if (bm != null) { if (bm.getConfig() == null) { bm = bm.copy(Bitmap.Config.RGB_565, false); if (bm == null && allowdefalut) { return getDefaultArtwork(context, small); } } } else if (allowdefalut) { bm = getDefaultArtwork(context, small); } return bm; } finally { try { if (in != null) { in.close(); } } catch (IOException e) { e.printStackTrace(); } } } return null; } /** * 对图片进行合适的缩放 * * @param options * @param target * @return */ public static int computeSampleSize(Options options, int target) { int w = options.outWidth; int h = options.outHeight; int candidateW = w / target; int candidateH = h / target; int candidate = Math.max(candidateW, candidateH); if (candidate == 0) { return 1; } if (candidate > 1) { if ((w > target) && (w / candidate) < target) { candidate -= 1; } } if (candidate > 1) { if ((h > target) && (h / candidate) < target) { candidate -= 1; } } return candidate; }
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