Does Pattern.compile cache?

Question

It is likely an implementation detail, but for the Oracle and IBM JDKs at least is the compiled pattern cached or do we as application developers need to perform the caching

Answer 1

As far as I know from looking at the code (JDK 6) it doesn't do caching but once constructed, Pattern object could be cached on application side and shared among multiple threads. Standard pattern seems to be to assign it to final static variable:

private static final Pattern p = Pattern.compile(",");