在Android 2.x中，是否有记录的方式来检查多个SD卡中的内容？

/mnt/sdcard

Environment

private static final Pattern DIR_SEPORATOR = Pattern.compile(\"/\");

/**
 * Raturns all available SD-Cards in the system (include emulated)
 *
 * Warning: Hack! Based on Android source code of version 4.3 (API 18)
 * Because there is no standart way to get it.
 * TODO: Test on future Android versions 4.4+
 *
 * @return paths to all available SD-Cards in the system (include emulated)
 */
public static String[] getStorageDirectories()
{
    // Final set of paths
    final Set<String> rv = new HashSet<String>();
    // Primary physical SD-CARD (not emulated)
    final String rawExternalStorage = System.getenv(\"EXTERNAL_STORAGE\");
    // All Secondary SD-CARDs (all exclude primary) separated by \":\"
    final String rawSecondaryStoragesStr = System.getenv(\"SECONDARY_STORAGE\");
    // Primary emulated SD-CARD
    final String rawEmulatedStorageTarget = System.getenv(\"EMULATED_STORAGE_TARGET\");
    if(TextUtils.isEmpty(rawEmulatedStorageTarget))
    {
        // Device has physical external storage; use plain paths.
        if(TextUtils.isEmpty(rawExternalStorage))
        {
            // EXTERNAL_STORAGE undefined; falling back to default.
            rv.add(\"/storage/sdcard0\");
        }
        else
        {
            rv.add(rawExternalStorage);
        }
    }
    else
    {
        // Device has emulated storage; external storage paths should have
        // userId burned into them.
        final String rawUserId;
        if(Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1)
        {
            rawUserId = \"\";
        }
        else
        {
            final String path = Environment.getExternalStorageDirectory().getAbsolutePath();
            final String[] folders = DIR_SEPORATOR.split(path);
            final String lastFolder = folders[folders.length - 1];
            boolean isDigit = false;
            try
            {
                Integer.valueOf(lastFolder);
                isDigit = true;
            }
            catch(NumberFormatException ignored)
            {
            }
            rawUserId = isDigit ? lastFolder : \"\";
        }
        // /storage/emulated/0[1,2,...]
        if(TextUtils.isEmpty(rawUserId))
        {
            rv.add(rawEmulatedStorageTarget);
        }
        else
        {
            rv.add(rawEmulatedStorageTarget + File.separator + rawUserId);
        }
    }
    // Add all secondary storages
    if(!TextUtils.isEmpty(rawSecondaryStoragesStr))
    {
        // All Secondary SD-CARDs splited into array
        final String[] rawSecondaryStorages = rawSecondaryStoragesStr.split(File.pathSeparator);
        Collections.addAll(rv, rawSecondaryStorages);
    }
    return rv.toArray(new String[rv.size()]);
}