Date Validation in Android

Question

I\'m new to Android programming and I\'m currently developing an app. Can someone help me on how to validate the date that is being input by the user if is it valid or not?<

Answer 1

DatePicker is quite painful to input birthday. Here is my solution:

Utils

public static final SimpleDateFormat BIRTHDAY_FORMAT_PARSER = new SimpleDateFormat("yyyy-MM-dd");
public static final String DASH_STRING = "-";
public static Calendar parseDateString(String date) {
        Calendar calendar = Calendar.getInstance();
        BIRTHDAY_FORMAT_PARSER.setLenient(false);
        try {
            calendar.setTime(BIRTHDAY_FORMAT_PARSER.parse(date));
        } catch (ParseException e) {}
        return calendar;
    }
public static boolean isValidBirthday(String birthday) {
        Calendar calendar = parseDateString(birthday);
        int year = calendar.get(Calendar.YEAR);
        int thisYear = Calendar.getInstance().get(Calendar.YEAR);
        return year >= 1900 && year < thisYear;
    }

Main Activity

private void setupBirthdayEditText() {
        mBirthdayEditText.addTextChangedListener(new TextWatcher() {
            int beforeTextChangedLength;
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                beforeTextChangedLength = charSequence.length();
            }

            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                if (!TextUtils.isEmpty(mBirthdayTextInputLayout.getError())) {
                    mBirthdayTextInputLayout.setError(null);
                    mBirthdayTextInputLayout.setErrorEnabled(false);
                }
            }

            @Override
            public void afterTextChanged(Editable editable) {
                int length = editable.length();
                // text is being removed
                if (beforeTextChangedLength > length) return;

                String str = editable.toString();
                String[] strArr = str.split(Utils.DASH_STRING);
                // only add dash after input year with zero dash and input month with one dash
                if ((length == YEAR_LENGTH && strArr.length == 1) || (length == YEAR_MONTH_LENGTH && strArr.length == 2)) {
                    mBirthdayEditText.setText(str + Utils.DASH_STRING);
                    mBirthdayEditText.setSelection(mBirthdayEditText.length());
                }
            }
        });
    }

protected boolean isAllFieldsValid() {
        String birthday = mBirthdayEditText.getText().toString().trim();
        if (!Utils.isValidBirthday(birthday)) {
            mBirthdayTextInputLayout.setError(getString(R.string.error_birth_date));
            return false;
        }

    return true;
}

activity_main.xml

This is not perfect as we shouldn't check validation with try catch and user have to look to the date format during typing, but it is simple and convenient if you want to avoid default date picker.