Steps to Reproduce

1. run keikai with a blank sheet with JDK 9 or above
2. visit keikai with a browser in locale zh_TW
3. type any character e.g. aaa in a cell

Current Result

Wrong groupMatchText: 65年JUL月18日, regex mask: ^[ \t]*(19\d\d|[2-9]\d\d\d|\d\d|\d)([A-Z\p{InLatin-1Supplement}]{3,9})([0]?[1-9]|[12][0-9]|3[01])[ \t]*$

Expected Result

no error

Debug Information

• https://bugs.openjdk.java.net/browse/JDK-8152154
• The exception happens at
  public FormatInfo(Pattern mask, String format, String groupMatchText, String ampm1MatchText, Locale locale) {
  ...
  if (!m.matches()) { throw new RuntimeException("Wrong groupMatchText: "+ groupMatchText+ ", regex mask: "+_mask); }
• In DateInputMask.java

  	private String[] getDate11(Locale locale, boolean withTime) {
  final AttributedCharacterIterator iter
  			= format.formatToCharacterIterator(cal.getTime());
  

DateFormat format = DateFormat.getDateInstance(DateFormat.MEDIUM, locale);

format is different between java versions, therefore, in that method,
With java 9, sb1 is 65年JUL月18日
with java 8, sb1 is JUL 18, 65

• Please ensure the solution works with both Java 8 and 9 or above.

Workaround

• run with Java 8
• run with VM option -Djava.locale.providers=JRE,CLDR