如何从SD卡android获取所有音频文件

Question

我想写一个从整个SD卡中获取所有mp3文件的类.但实际上它只能将音频文件直接放在SD卡上.因此它不会搜索子文件夹.我想使用Mediastore但我不会把它带到一个arraylist.也许你可以帮助我,非常感谢并且抱歉做了一个菜鸟;)vinzenz

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

import de.me.musicplayer.SongsManager.FileExtensionFilter;

import android.database.Cursor;
import android.net.Uri;
import android.provider.MediaStore;




public class SongsManager {

final String MEDIA_PATH = new String("/sdcard/");
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) {
        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

final String MEDIA_PATH = Environment.getExternalStorageDirectory()
        .getPath() + "/";
private ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();
private String mp3Pattern = ".mp3";

// Constructor
public SongsManager() {

}

/**
 * Function to read all mp3 files 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);
    }
}

Answer 2

你也可以使用 ContentResolver 类来获取我已经这样做了并且它工作正常

public void getSongListFromStorage() {
        //retrieve song info
  ContentResolver musicResolver = getContentResolver();
  Uri musicUri = android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
  Cursor musicCursor = musicResolver.query(musicUri, null, null, null, null);

  if (musicCursor != null && musicCursor.moveToFirst()) {
  //get columns
  int titleColumn = musicCursor.getColumnIndex
                    (android.provider.MediaStore.Audio.Media.TITLE);
  int idColumn = musicCursor.getColumnIndex
                    (android.provider.MediaStore.Audio.Media._ID);
 int artistColumn = musicCursor.getColumnIndex
                    (android.provider.MediaStore.Audio.Media.ARTIST);
 //add songs to list
  do {
      long thisId = musicCursor.getLong(idColumn);
      String thisTitle = musicCursor.getString(titleColumn);
      String thisArtist = musicCursor.getString(artistColumn);
      songList.add(new Song(thisId, thisTitle, thisArtist));
      } while (musicCursor.moveToNext());
   }
 }