How to check if a given Regex is valid?

Question

I have a little program allowing users to type-in some regular expressions. afterwards I like to check if this input is a valid regex or not.

I\'m w

Answer 1

Most obvious thing to do would be using compile method in java.util.regex.Pattern and catch PatternSyntaxException

String myRegEx;
...
...
Pattern p = Pattern.compile(myRegEx);

This will throw a PatternSyntaxException if myRegEx is invalid.