Resolved: How do I separate 2 groups with a regex?

Question:

First time asking a question. So, I’m learning regex and I got this exercise:
input string:
Retreat the following two groups using a regex to get the following:
and
avoiding the colon : after CommunicationsException.
My solution is:
It worked, but I’m sure its really messy. Could anybody explain to me how to upgrade it?

Answer:

You can match Cause by: and then match all text up to the next colon, and then start matching from any non-whitespace that is not a colon till the end of string:
See the regex demo. If the match is at the start of the string, add ^ at the start.
As an alternative, if you do not care what text is at the string beginning, you can even use ^[^:]+:[^:]+|[^:\s].*.
Details:

• ^ – start of string
• Caused\s+by: – Caused by: with any one or more whitespaces between Caused and by
• [^:]+ – one or more chars other than :
• | – or
• [^:\s] – a char other than whitespace and :
• .* – the rest of the line.

If you have better answer, please add a comment about this, thank you!