https://www.dotnetzone.gr:443/cs/blogs/birbilis/archive/2012/06/01/validating-e-mails-using-regular-expressions-in-java.aspxTo sum up the discussion at http://stackoverflow.com/questions/1360113/is-java-regex-thread-safe/, you can reuse (keep in static variables) the compiled Pattern(s) and tell them to give you new Matchers when needed to validate those regex pattens againstelCommunityServer 2.1 SP3 (Build: 20423.1)