音乐播放器通常需要获取歌曲的专辑、作者、标题、年代等信息，将这些信息显示到UI界面上。
1、一种方式：解析媒体文件
命名空间：android.media.MediaMetadataRetriever
android提供统一的接口MediaMetadataRetriever解析媒体文件、获取媒体文件中取得帧和元数据（视频/音频包含的标题、格式、艺术家等信息）。
1 MediaMetadataRetriever mmr = new MediaMetadataRetriever(); 2 String str = getExternalStorageDirectory() + "music/hetangyuese.mp3"; 3 mmr.setDataSource(str); 4 // api level 10, 即从GB2.3.3开始有此功能 5 String title = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_TITLE); 6 // 专辑名 7 String album = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_ALBUM); 8 // 媒体格式 9 String mime = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_MIMETYPE); 10 // 艺术家 11 String artist = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_ARTIST); 12 // 播放时长单位为毫秒 13 String duration = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION); 14 // 从api level 14才有，即从ICS4.0才有此功能 15 String bitrate = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_BITRATE); 16 // 路径 17 String date = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DATE);
（1）关于视频缩略图：
2.2 之后：因为用了ThumbnailUtils类:
1 Bitmap b = ThumbnailUtils.createVideoThumbnail(path,Video.Thumbnails.MICRO_KIND); 2 ImageView iv = new ImageView(this);
2.2 之前：
使用MediaMetadataRetriever这个类；还可以通过getFrameAtTime方法取得指定time位置的Bitmap，即可以实现抓图（包括缩略图）功能
但是 里面有个问题
1.0之后 这个类被隐藏了 貌似2.3之后这个类又出现了，但是还可以直接copy源码进去使用:http://blog.csdn.net/lostinai/article/details/7734699 (教程)
1 // 对于视频，取第一帧作为缩略图，也就是怎样从filePath得到一个Bitmap对象。
2 private Bitmap createVideoThumbnail(String filePath) {
3 Bitmap bitmap = null;
4 MediaMetadataRetriever retriever = new MediaMetadataRetriever();
5 try {
6 retriever.setMode(MediaMetadataRetriever.MODE_CAPTURE_FRAME_ONLY);
7 retriever.setDataSource(filePath);
8 bitmap = retriever.captureFrame();
9 } catch(IllegalArgumentException ex) {
10 // Assume this is a corrupt video file
11 } catch (RuntimeException ex) {
12 // Assume this is a corrupt video file.
13 } finally {
14 try {
15 retriever.release();
16 } catch (RuntimeException ex) {
17 // Ignore failures while cleaning up.
18 }
19 }
20 return bitmap;
21 }
（2）关于音乐缩略图：
1 // 对于音乐，取得AlbumImage作为缩略图，还是用MediaMetadataRetriever
2 private Bitmap createAlbumThumbnail(String filePath) {
3 Bitmap bitmap = null;
4 MediaMetadataRetriever retriever = new MediaMetadataRetriever();
5 try {
6 retriever.setMode(MediaMetadataRetriever.MODE_GET_METADATA_ONLY);
7 retriever.setDataSource(filePath);
8 byte[] art = retriever.extractAlbumArt();
9 bitmap = BitmapFactory.decodeByteArray(art, 0, art.length);
10 } catch(IllegalArgumentException ex) {
11 } catch (RuntimeException ex) {
12 } finally {
13 try {
14 retriever.release();
15 } catch (RuntimeException ex) {
16 // Ignore failures while cleaning up.
17 }
18 }
19 return bitmap;
20 }
注意：直接得到Bitmap对象，把图片缩小到合适大小就OK。
这样获取出来的，信息有时候可能有乱码：
1、Java如何获取文件编码格式 （使用第三方库进行处理）
2、自己判断字符串是否有乱码，然后自行处理。
1 private boolean isMessyCode(String strName) {
2 try {
3 Pattern p = Pattern.compile("\\s*|\t*|\r*|\n*");
4 Matcher m = p.matcher(strName);
5 String after = m.replaceAll("");
6 String temp = after.replaceAll("\\p{P}", "");
7 char[] ch = temp.trim().toCharArray();
8
9 int length = (ch != null) ? ch.length : 0;
10 for (int i = 0; i < length; i++) {
11 char c = ch[i];
12 if (!Character.isLetterOrDigit(c)) {
13 String str = "" + ch[i];
14 if (!str.matches("[\u4e00-\u9fa5]+")) {
15 return true;
16 }
17 }
18 }
19 } catch (Exception e) {
20 e.printStackTrace();
21 }
22
23 return false;
24 }
检查字符串是否乱码，乱码情况下要做相应的处理
2、二种方式：读取媒体文件数据库（避免乱码）
创建java bean：
1 public class MediaInfo {
2 private int playDuration = 0;
3 private String mediaName = "";
4 private String mediaAlbum = "";
5 private String mediaArtist = "";
6 private String mediaYear = "";
7 private String mFileName = "";
8 private String mFileType = "";
9 private String mFileSize = "";
10 private String mFilePath = "";
11
12 public Bitmap getmBitmap() {
13 return mBitmap;
14 }
15
16 public void setmBitmap(Bitmap mBitmap) {
17 this.mBitmap = mBitmap;
18 }
19
20 private Bitmap mBitmap = null;
21
22 public String getMediaName() {
23 return mediaName;
24 }
25
26 public void setMediaName(String mediaName) {
27 try {
28 mediaName =new String (mediaName.getBytes("ISO-8859-1"),"GBK");
29 } catch (UnsupportedEncodingException e) {
30 // TODO Auto-generated catch block
31 e.printStackTrace();
32 }
33 this.mediaName = mediaName;
34 }
35
36 public String getMediaAlbum() {
37 return mediaAlbum;
38 }
39
40 public void setMediaAlbum(String mediaAlbum) {
41 try {
42 mediaAlbum =new String (mediaAlbum.getBytes("ISO-8859-1"),"GBK");
43 } catch (UnsupportedEncodingException e) {
44 // TODO Auto-generated catch block
45 e.printStackTrace();
46 }
47 this.mediaAlbum = mediaAlbum;
48 }
49
50 public String getMediaArtist() {
51 return mediaArtist;
52 }
53
54 public void setMediaArtist(String mediaArtist) {
55 try {
56 mediaArtist =new String (mediaArtist.getBytes("ISO-8859-1"),"GBK");
57 } catch (UnsupportedEncodingException e) {
58 // TODO Auto-generated catch block
59 e.printStackTrace();
60 }
61 this.mediaArtist = mediaArtist;
62 }
63 }
媒体信息bean
操作类：
1 public class MediaInfoProvider {
2
3 /**
4 * context
5 */
6 private Context mContext = null;
7
8 /**
9 * data path
10 */
11 private static final String dataPath = "/mnt";
12
13 /**
14 * query column
15 */
16 private static final String[] mCursorCols = new String[] {
17 MediaStore.Audio.Media._ID, MediaStore.Audio.Media.DISPLAY_NAME,
18 MediaStore.Audio.Media.TITLE, MediaStore.Audio.Media.DURATION,
19 MediaStore.Audio.Media.ARTIST, MediaStore.Audio.Media.ALBUM,
20 MediaStore.Audio.Media.YEAR, MediaStore.Audio.Media.MIME_TYPE,
21 MediaStore.Audio.Media.SIZE, MediaStore.Audio.Media.DATA };
22
23 /**
24 * MediaInfoProvider
25 * @param context
26 */
27 public MediaInfoProvider(Context context) {
28 this.mContext = context;
29 }
30
31 /**
32 * get the media file info by path
33 * @param filePath
34 * @return
35 */
36 public MediaInfo getMediaInfo(String filePath) {
37
38 /* check a exit file */
39 File file = new File(filePath);
40 if (file.exists()) {
41 Toast.makeText(mContext, "sorry, the file is not exit!",
42 Toast.LENGTH_SHORT);
43 }
44
45 /* create the query URI, where, selectionArgs */
46 Uri Media_URI = null;
47 String where = null;
48 String selectionArgs[] = null;
49
50 if (filePath.startsWith("content://media/")) {
51 /* content type path */
52 Media_URI = Uri.parse(filePath);
53 where = null;
54 selectionArgs = null;
55 } else {
56 /* external file path */
57 if(filePath.indexOf(dataPath) < 0) {
58 filePath = dataPath + filePath;
59 }
60 Media_URI = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
61 where = MediaColumns.DATA + "=?";
62 selectionArgs = new String[] { filePath };
63 }
64
65 /* 查询 */
66 Cursor cursor = mContext.getContentResolver().query(Media_URI,
67 mCursorCols, where, selectionArgs, null);
68 if (cursor == null || cursor.getCount() == 0) {
69 return null;
70 } else {
71 cursor.moveToFirst();
72 MediaInfo info = getInfoFromCursor(cursor);
73 printInfo(info);
74 return info;
75 }
76 }
77
78 /**
79 * 获取媒体信息
80 * @param cursor
81 * @return
82 */
83 private MediaInfo getInfoFromCursor(Cursor cursor) {
84 MediaInfo info = new MediaInfo();
85
86 /* file name */
87 if(cursor.getString(1) != null) {
88 info.setmFileName(cursor.getString(1));
89 }
90 /* media name */
91 if(cursor.getString(2) != null) {
92 info.setMediaName(cursor.getString(2));
93 }
94 /* play duration */
95 if(cursor.getString(3) != null) {
96 info.setPlayDuration(cursor.getInt(3));
97 }
98 /* artist */
99 if(cursor.getString(4) != null) {
100 info.setMediaArtist(cursor.getString(4));
101 }
102 /* album */
103 if(cursor.getString(5) != null) {
104 info.setMediaAlbum(cursor.getString(5));
105 }
106 /* media year */
107 if (cursor.getString(6) != null) {
108 info.setMediaYear(cursor.getString(6));
109 } else {
110 info.setMediaYear("undefine");
111 }
112 /* media type */
113 if(cursor.getString(7) != null) {
114 info.setmFileType(cursor.getString(7).trim());
115 }
116 /* media size */
117 if (cursor.getString(8) != null) {
118 float temp = cursor.getInt(8) / 1024f / 1024f;
119 String sizeStr = (temp + "").substring(0, 4);
120 info.setmFileSize(sizeStr + "M");
121 } else {
122 info.setmFileSize("undefine");
123 }
124 /* media file path */
125 if (cursor.getString(9) != null) {
126 info.setmFilePath(cursor.getString(9));
127 }
128
129 return info;
130 }
131 }
时间： 2024-10-07 13:32:10