如何从Android上的内部和外部存储中读取mp3文件？

Question

我的代码如下。它在我的外部SD卡存储中找到所有mp3。我需要从内部存储中读取所有mp3文件。 MediaStore对我来说很复杂。我设法在一年前做到了，但丢失了文件。如果有人可以帮助我，那就太好了。我无法轻易找到我需要的信息，我在这里搜索。这将对我有很大帮助，所以回答或建议将得到很好的赞赏。谢谢。

import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
import java.util.HashMap;


import android.database.Cursor;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;


public class SongsManager {



    final String MEDIA_PATH = MediaStore.Audio.Media.IS_MUSIC + " != 0";

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


    private String mp3Pattern = ".mp3";



    // Constructor
    public SongsManager() {

    }

    /**
     * Function to read all mp3 files from sdcard
     * and store the details in ArrayList
     */
    public ArrayList<HashMap<String, String>> getPlayList() {
        System.out.println(MEDIA_PATH);
        if (MEDIA_PATH != null) {
            File home = new File(MEDIA_PATH);
            File[] listFiles = home.listFiles();
            if (listFiles != null && listFiles.length > 0) {
                for (File file : listFiles) {
                    System.out.println(file.getAbsolutePath());
                    if (file.isDirectory()) {
                        scanDirectory(file);
                    } else {
                        addSongToList(file);
                    }
                }
            }
        }
        // return songs list array
        return songsList;
    }

    private void scanDirectory(File directory) {
        if (directory != null) {
            File[] listFiles = directory.listFiles();
            if (listFiles != null && listFiles.length > 0) {
                for (File file : listFiles) {
                    if (file.isDirectory()) {
                        scanDirectory(file);
                    } else {
                        addSongToList(file);
                    }

                }
            }
        }
    }

    private void addSongToList(File song) {
        if (song.getName().endsWith(mp3Pattern)) {
            HashMap<String, String> songMap = new HashMap<String, String>();
            songMap.put("songTitle",
                    song.getName().substring(0, (song.getName().length() - 4)));
            songMap.put("songPath", song.getPath());

            // Adding each song to SongList
            songsList.add(songMap);
        }
    }

    /**
     * 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"));
        }
    }



}