TypefaceUtil.java

/**
     * Using reflection to override default typeface
     * NOTICE: DO NOT FORGET TO SET TYPEFACE FOR APP THEME AS DEFAULT TYPEFACE WHICH WILL BE OVERRIDDEN
     *Use
     * @param context                    to work with assets
     * @param defaultFontNameToOverride  for example "monospace"
     * @param customFontFileNameInAssets file name of the font from assets
     */
    public static void overrideFont(Context context, String defaultFontNameToOverride, String customFontFileNameInAssets) {
        try {
            final Typeface customFontTypeface = Typeface.createFromAsset(context.getAssets(), customFontFileNameInAssets);

            final Field defaultFontTypefaceField = Typeface.class.getDeclaredField(defaultFontNameToOverride);
            defaultFontTypefaceField.setAccessible(true);
            defaultFontTypefaceField.set(null, customFontTypeface);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }