如何将音频媒体存储持续时间转换为分钟和秒

Question

我正在使用androidhive.info中的音频播放器教程，在SongsManager.java中，我试图将持续时间转换为分秒。我已经设法做到了，但我一直得到NumberFormatException，我不知道该怎么处理。部分代码在这里：

public ArrayList<HashMap<String, String>> getPlayList(Context c) {
    String selectionMimeType = MediaStore.Files.FileColumns.MIME_TYPE + "=?";
    /*use content provider to get beginning of database query that queries for all audio by display name, path
    and mimtype which i dont use but got it incase you want to scan for mp3 files only you can compare with RFC  mimetype for mp3's
    */
    final Cursor mCursor = c.getContentResolver().query(
            MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
            new String[] { MediaStore.Audio.Media.TITLE, MediaStore.Audio.Media.DATA,MediaStore.Audio.Media.MIME_TYPE,MediaStore.Audio.Media.ARTIST,MediaStore.Audio.Media.ALBUM,MediaStore.Audio.Media.DURATION }, null, null,
            "LOWER(" + MediaStore.Audio.Media.TITLE + ") ASC");
    String songs_name = "";
    String mAudioPath = "";
    String songs_artist = "";
    String songs_album = "";
    String songs_duration = "";
    /* run through all the columns we got back and save the data we need into the arraylist for our listview*/
    if (mCursor.moveToFirst()) {
        do {
            String file_type = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.MIME_TYPE));
            songs_name = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.TITLE));
            mAudioPath = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA));
            songs_artist = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST));
            songs_album = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ALBUM));
            songs_duration = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DURATION));
            HashMap<String, String> song = new HashMap<String, String>();
            songs_duration = setCorrectDuration(songs_duration);
            song.put("songTitle", songs_name);
            song.put("songPath", mAudioPath);
            song.put("songArtist", songs_artist);
            song.put("songAlbum", songs_album);
            song.put("songDuration", songs_duration);
            songsList.add(song);
        } while (mCursor.moveToNext());
    }   
    mCursor.close(); //cursor has been consumed so close it
    return songsList;
}
private String setCorrectDuration(String songs_duration) {
    // TODO Auto-generated method stub
    if(Integer.valueOf(songs_duration) != null) {
        int time = Integer.valueOf(songs_duration);
        int seconds = time/1000;
        int minutes = seconds/60;
        seconds = seconds % 60;
        if(seconds<10) {
            songs_duration = String.valueOf(minutes) + ":0" + String.valueOf(seconds);
        } else {
            songs_duration = String.valueOf(minutes) + ":" + String.valueOf(seconds);
        }
        return songs_duration;
    }
    return null;
}

这是LogCat:的一部分

10-28 23:39:13.047:W/dalvikvm（30524）：threadid=1：线程退出未捕获的异常（组=0x422f2700）10-28 23:39:13.047:E/AndroidRuntime（30524）：致命异常：main 10-28 23:39:13.047:E/AndroidRuntime（30524）：java.lang.RuntimeException：无法启动活动组件信息｛com.vany.vansmusic/com.vany.vansmusic.AndroidBuildingMusicPlayerActivity｝：java.lang.NumberFormatException：无效的int："null"

10-28 23:39:13.047:E/AndroidRuntime（30524）：在android.app.ActivityThread.performLaunchActivity（ActivityThread.java：2305）10-28 23:39:13.047:E/AndroidRuntime（30524）：在android.app.ActivityThread.handleLaunchActivity（ActivityThreads.java:2359）10-28 23:39:13.047:E/AndroidRuntime（30524）：在android.app.ActivityThread.access$700（ActivityThreads.java:165）10-2823:39:13.047:E/AndroidRuntime（30524）：在android.app.ActivityThread$H.handleMessage（ActivityThreads.java:1326）

我真的很感激你的帮助。

更新：为任何有相同或类似问题的人找出答案：

if (mCursor.moveToFirst()) {
    do {
        String file_type = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.MIME_TYPE));
        songs_name = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.TITLE));
        mAudioPath = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA));
        songs_artist = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST));
        songs_album = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ALBUM));
        songs_duration = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DURATION));
        HashMap<String, String> song = new HashMap<String, String>();
        if(String.valueOf(songs_duration) != null) {
            try {
                Long time = Long.valueOf(songs_duration);
                long seconds = time/1000;
                long minutes = seconds/60;
                seconds = seconds % 60;
                if(seconds<10) {
                    String csongs_duration = String.valueOf(minutes) + ":0" + String.valueOf(seconds);
                    song.put("songDuration", csongs_duration);
                } else {
                    String ccsongs_duration = String.valueOf(minutes) + ":" + String.valueOf(seconds);
                    song.put("songDuration", ccsongs_duration);
                }
            } catch(NumberFormatException e) {
                song.put("songDuration", songs_duration);
            }
        } else {
            String nothing = "0";
            song.put("songDuration", nothing);
        }
        song.put("songTitle", songs_name);
        song.put("songPath", mAudioPath);
        song.put("songArtist", songs_artist);
        song.put("songAlbum", songs_album);
        songsList.add(song);
    } while (mCursor.moveToNext());
}   
mCursor.close(); //cursor has been consumed so close it
return songsList;

Answer 1

http://developer.android.com/reference/android/provider/MediaStore.Audio.AudioColumns.html您需要检查查询的返回类型。DURATION字段不返回String，而是返回long。

String songs_duration = "";

应该是

long songs_duration = "";

这样您就不必解析或使用null检查了。除此之外，你的数学和一切都很好。