search a file from directory and get storage directorys from android device(i use tablet here)

public class Explorer {    String TAG = "Explorer";    private final String DISK_DIR             = "/mnt";    public static final int DIR_SDCARD         = 0;     public static final int DIR_SDCARD_EX     = 1; // external sdcard    public static final int DIR_USB         = 2; // usb external storage        private static List<String> pathList = new ArrayList<String>();        public String getDiskPath(int typeDir) {        File[] files = new File(DISK_DIR).listFiles();        String filePath;        for (int i = 0; i < files.length; i++) {            filePath = files[i].getAbsolutePath().toLowerCase();            Log.d(TAG, "getDiskPath " + filePath);            switch (typeDir) {            case DIR_SDCARD:                if(filePath.equals("/mnt/sdcard"))                    return filePath;                break;            case DIR_SDCARD_EX:                if (filePath.contains("sdcard") && filePath.contains("ext")) {                    return filePath;                }                break;            case DIR_USB:                if(filePath.contains("usb"))                    return filePath;                break;            }        }        return null;    }        private void loadFileList(String dir, final String fileType) {        File fileDir = new File(dir);        if (fileDir.exists()) {            FilenameFilter filter = new FilenameFilter() {                public boolean accept(File dir, String filename) {                    File sel = new File(dir, filename);                    return filename.endsWith(fileType) || sel.isDirectory();                }            };            File[] files = fileDir.listFiles(filter);            if(files!=null){                for (File file : files) {                    String absolutePath = file.getAbsolutePath();                    if(file.isDirectory()){                        loadFileList(absolutePath, fileType);                    }else {                        pathList.add(absolutePath);                    }                }            }                    }    }        public List<String> getFileList(String dir, final String fileType){        loadFileList(dir, fileType);        return pathList;    }}