@Override
    public String generateFileName(int logLevel, long timestamp) {
        SimpleDateFormat sdf = mLocalDateFormat.get();
        sdf.setTimeZone(TimeZone.getDefault());
        return sdf.format(new Date(timestamp));
    }
Generate a file name which represent a specific date.
android/android_framework/base/src/main/java/com/elvishew/xlog/printer/file/naming/DateFileNameGenerator.java