EditText input filter

EditTextInputFilter.java

editText.setFilters(new InputFilter[] {
    new InputFilter() {
        @Override
        public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
            if (!somePattern.matcher(source).matches()) {
                //return empty to refuse
                return "";
            } else {
                //return null if accept
                return null;
            }
        }
    }
});