Question

I wonder while the following regex returns false. I can’t see while a “|” should not match. Any ideas? And how do I allow the pattern to match “|”?

Pattern pattern = Pattern.compile("([^\\*|\\\\|\\{|\\}|\\[|\\]|=|>|<])*");
boolean valid = pattern.matcher("|").matches();

Thanks in advance.

Answer 1

The [^ ] expression matches any character not in the brackets. Since | is in the brackets, it is not matched. All characters (except a few, like \ and ]) are taken literally inside the [^ ] expression.

I think you meant to say something like this:

([^*\\{}[\]=><])*

This matches anything but these characters:

*\{}[]=><

To put it in a string, you would do this:

"([^*\\\\{}[\\]=><])*"