Playing music from SD Card works on emulator but not on phone

Question

I'm creating an android application that plays the users music. I've got it to work fine on an emulator but it's not working when I install it on a phone, it crashes at this line:

int songIndex = new Random().nextInt(songsList.size());

Because songList.size() is returning 0, since it seems the music can't be found when it runs on a phone. I've put a Micro SD card in the phone, and have loaded music onto it (in the root folder). I'm using the following to get the path:

final String MEDIA_PATH = Environment.getExternalStorageDirectory().getAbsolutePath();

On both the emulator and the phone, the returned string from this is /mnt/sdcard. But it's only working on the emulator. I've also included the following permission in my manifest file:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>

Any ideas?

EDIT:

I didn't include this because I didn't think it would help much, but this is the code I'm using to actually get the songList:

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());

            //Add song to song list
            songsList.add(song);
        }
    }

    return songsList;
}

I've added in the code that is returning the empty playlist on the phone (but not on an emulator) — JoshTFS, Oct 06 '13 at 11:14
i think your problem is just about providing wrong song path — Ahmad Dwaik 'Warlock', Oct 06 '13 at 11:16
Yes, I agree. I'm not sure how to get the correct one though, as I mentioned it works fine on the emulator and apparently the path for both is /mnt/sdcard. — JoshTFS, Oct 06 '13 at 11:19

score 1 · Answer 1 · edited May 23 '17 at 12:21

How about

return Environment.getExternalStorageDirectory().toString() + "/Music";

This will return the path to internal SD mount point like "/mnt/sdcard"

This is a better way of coding than hard coding in the path.

EDIT

To get it working on all devices try the code below from this thread where they discuss that Android has no concept of "external SD", aside from external storage. OP then came up with the following solution for his problem as a result of all the answers and comments he was given.

import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;

import android.os.Environment;
import android.util.Log;

public class ExternalStorage {

public static final String SD_CARD = "sdCard";
public static final String EXTERNAL_SD_CARD = "externalSdCard";

/**
 * @return True if the external storage is available. False otherwise.
 */
public static boolean isAvailable() {
    String state = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED.equals(state) || Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
        return true;
    }
    return false;
}

public static String getSdCardPath() {
    return Environment.getExternalStorageDirectory().getPath() + "/";
}

/**
 * @return True if the external storage is writable. False otherwise.
 */
public static boolean isWritable() {
    String state = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED.equals(state)) {
        return true;
    }
    return false;

}

/**
 * @return A map of all storage locations available
 */
public static Map<String, File> getAllStorageLocations() {
    Map<String, File> map = new HashMap<String, File>(10);

    List<String> mMounts = new ArrayList<String>(10);
    List<String> mVold = new ArrayList<String>(10);
    mMounts.add("/mnt/sdcard");
    mVold.add("/mnt/sdcard");

    try {
        File mountFile = new File("/proc/mounts");
        if(mountFile.exists()){
            Scanner scanner = new Scanner(mountFile);
            while (scanner.hasNext()) {
                String line = scanner.nextLine();
                if (line.startsWith("/dev/block/vold/")) {
                    String[] lineElements = line.split(" ");
                    String element = lineElements[1];

                    // don't add the default mount path
                    // it's already in the list.
                    if (!element.equals("/mnt/sdcard"))
                        mMounts.add(element);
                }
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }

    try {
        File voldFile = new File("/system/etc/vold.fstab");
        if(voldFile.exists()){
            Scanner scanner = new Scanner(voldFile);
            while (scanner.hasNext()) {
                String line = scanner.nextLine();
                if (line.startsWith("dev_mount")) {
                    String[] lineElements = line.split(" ");
                    String element = lineElements[2];

                    if (element.contains(":"))
                        element = element.substring(0, element.indexOf(":"));
                    if (!element.equals("/mnt/sdcard"))
                        mVold.add(element);
                }
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }


    for (int i = 0; i < mMounts.size(); i++) {
        String mount = mMounts.get(i);
        if (!mVold.contains(mount))
            mMounts.remove(i--);
    }
    mVold.clear();

    List<String> mountHash = new ArrayList<String>(10);

    for(String mount : mMounts){
        File root = new File(mount);
        if (root.exists() && root.isDirectory() && root.canWrite()) {
            File[] list = root.listFiles();
            String hash = "[";
            if(list!=null){
                for(File f : list){
                    hash += f.getName().hashCode()+":"+f.length()+", ";
                }
            }
            hash += "]";
            if(!mountHash.contains(hash)){
                String key = SD_CARD + "_" + map.size();
                if (map.size() == 0) {
                    key = SD_CARD;
                } else if (map.size() == 1) {
                    key = EXTERNAL_SD_CARD;
                }
                mountHash.add(hash);
                map.put(key, root);
            }
        }
    }

    mMounts.clear();

    if(map.isEmpty()){
             map.put(SD_CARD, Environment.getExternalStorageDirectory());
    }
    return map;
}
}

USAGE

Map<String, File> externalLocations = ExternalStorage.getAllStorageLocations();
File sdCard = externalLocations.get(ExternalStorage.SD_CARD);
File externalSdCard = externalLocations.get(ExternalStorage.EXTERNAL_SD_CARD);

Interesting, adding + "/Music" makes it work on the phone but not on the emulator. Also, it's grabbing the music from the Music folder from the internal storage of the phone, not the SD Card. — JoshTFS, Oct 06 '13 at 12:00
@JoshTFS that is probably because the emulator and the phone store things in different locations. Try adding `/external_sd/Music` let me know if that works — ilovepjs, Oct 06 '13 at 12:03
@JoshTFS please see the edit above and for a quicker fix try first `Environment.DIRECTORY_MUSIC` and if that doesnt work `externalSdCard/Music` — ilovepjs, Oct 06 '13 at 12:15

score 0 · Answer 2 · answered Oct 06 '13 at 11:58

0

I think the reason is , you have run the app connecting your phone to pc in debug mode. And your phone is in Mass Storage Mode , so when connected to pc your SD card is unmounted. That's why you are not getting the songs in your list. Hope it helps.

answered Oct 06 '13 at 11:58

ayon

2,180
2
17
32

Playing music from SD Card works on emulator but not on phone

2 Answers2

Linked