Question

我正在开发Android中的音乐播放器，但仍然在阅读MP3文件。这是我读取所有mp3文件的代码。但它不会从设备中撤回任何文件（尽管我使用adb复制了一些文件）。我也希望它使用专辑，艺术家等列出。请帮助。

final String MEDIA_PATH = Environment.getExternalStorageDirectory()+"";

private ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();

// Constructor
public SongsManager(){

}

/**
 * Function to read all mp3 files from sdcard
 * and store the details in ArrayList
 * */
public ArrayList<HashMap<String, String>> getPlayList(){
    File home = new File(MEDIA_PATH);

    //if (home.listFiles(new FileExtensionFilter()).length > 0) {
    if (home.listFiles(new FileExtensionFilter())!=null) {

        for (File file : home.listFiles(new FileExtensionFilter())) {
            HashMap<String, String> song = new HashMap<String, String>();
            song.put("songTitle", file.getName().substring(0, (file.getName().length() - 4)));
            song.put("songPath", file.getPath());

            // Adding each song to SongList
            songsList.add(song);
        }
    }
    // return songs list array
    return songsList;
}

/**
 * Class to filter files which are having .mp3 extension
 * */
class FileExtensionFilter implements FilenameFilter {
    public boolean accept(File dir, String name) {
        return (name.endsWith(".mp3") || name.endsWith(".MP3"));
    }
}

Answer 1

这里我修改了你的getPlayList（）方法。调查一下。

ArrayList<HashMap<String,String>> getPlayList(String rootPath) {
            ArrayList<HashMap<String,String>> fileList = new ArrayList<>();


            try {
                File rootFolder = new File(rootPath);
                File[] files = rootFolder.listFiles(); //here you will get NPE if directory doesn't contains  any file,handle it like this.
                for (File file : files) {
                    if (file.isDirectory()) {
                        if (getPlayList(file.getAbsolutePath()) != null) {
                            fileList.addAll(getPlayList(file.getAbsolutePath()));
                        } else {
                            break;
                        }
                    } else if (file.getName().endsWith(".mp3")) {
                        HashMap<String, String> song = new HashMap<>();
                        song.put("file_path", file.getAbsolutePath());
                        song.put("file_name", file.getName());
                        fileList.add(song);
                    }
                }
                return fileList;
            } catch (Exception e) {
                return null;
            }
        }

你可以得到这样的歌曲名称和歌曲路径：

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
ArrayList<HashMap<String,String>> songList=getPlayList("/storage/sdcard1/");
        if(songList!=null){
        for(int i=0;i<songList.size();i++){
        String fileName=songList.get(i).get("file_name");
        String filePath=songList.get(i).get("file_path");
        //here you will get list of file name and file path that present in your device
        log.e("file details "," name ="+fileName +" path = "+filePath);
        }
        }
    }

注意：使用“/ storage / sdcard1 /”从sdCard读取文件并使用Environment.getExternalStorageDirectory（）。getAbsolutePath（）从手机内存中读取文件

希望这会对你有所帮助。

Answer 2

试试这个

String path;
File sdCardRoot = Environment.getExternalStorageDirectory();
File dir = new File(sdCardRoot.getAbsolutePath() + "/yourDirectory/");

if (dir.exists()) {

    if (dir.listFiles() != null) {
        for (File f : dir.listFiles()) {
            if (f.isFile())
                path = f.getName();

            if (path.contains(".mp3")) {
                yourArrayList.add(path);

            }
        }
    }
}

Answer 3

希望你已经找到了答案，但可能会更好，如果你想尝试，这是你的解决方案使用以下代码从特定文件夹或所有文件中读取MP3文件，

首先创建1个模型类，如下面的给定，列表中的GET和SET文件。

AudioModel.class

public class AudioModel {

    String aPath;
    String aName;
    String aAlbum;
    String aArtist;

    public String getaPath() {
        return aPath;
    }

    public void setaPath(String aPath) {
        this.aPath = aPath;
    }

    public String getaName() {
        return aName;
    }

    public void setaName(String aName) {
        this.aName = aName;
    }

    public String getaAlbum() {
        return aAlbum;
    }

    public void setaAlbum(String aAlbum) {
        this.aAlbum = aAlbum;
    }

    public String getaArtist() {
        return aArtist;
    }

    public void setaArtist(String aArtist) {
        this.aArtist = aArtist;
    }
}

现在我们有了Model Class，使用下面的代码来读取文件夹或设备中的所有MP3文件。

这将返回包含音乐NAME, PATH, ARTIST, ALBUM的所有MP3文件的列表。如果您想了解更多详情，请参阅documentation for Media.Store.Audio

public List<AudioModel> getAllAudioFromDevice(final Context context) {

        final List<AudioModel> tempAudioList = new ArrayList<>();

        Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        String[] projection = {MediaStore.Audio.AudioColumns.DATA, MediaStore.Audio.AudioColumns.ALBUM, MediaStore.Audio.ArtistColumns.ARTIST,};
        Cursor c = context.getContentResolver().query(uri, projection, MediaStore.Audio.Media.DATA + " like ? ", new String[]{"%yourFolderName%"}, null);

        if (c != null) {
            while (c.moveToNext()) {

                AudioModel audioModel = new AudioModel();
                String path = c.getString(0);
                String album = c.getString(1);
                String artist = c.getString(2);

                String name = path.substring(path.lastIndexOf("/") + 1);

                audioModel.setaName(name);
                audioModel.setaAlbum(album);
                audioModel.setaArtist(artist);
                audioModel.setaPath(path);

                Log.e("Name :" + name, " Album :" + album);
                Log.e("Path :" + path, " Artist :" + artist);

                tempAudioList.add(audioModel);
            }
            c.close();
        }

        return tempAudioList;
    }

要读取特定文件夹的文件，请使用此查询（在查询中写入目标文件夹名称）

Cursor c = context.getContentResolver().query(uri,
                                          projection, 
                                          MediaStore.Audio.Media.DATA + " like ? ", 
                                          new String[]{"%yourFolderName%"}, // yourFolderName 
                                          null);

如果您想要设备上的所有文件，请使用以下查询：

Cursor c = context.getContentResolver().query(uri,
                                          projection, 
                                          null, 
                                          null, 
                                          null);

不要忘记添加存储权限。

列出android中的所有Mp3文件

4 个答案: