regexp for find key value pairs separated by colon

I'm having trouble coming up with a regular expression for a string in the given form:

123123<key:value><key:value>,21313<key:val开发者_JAVA百科ue><key:value>

where the key:value pairs are optional, but we must not have two colons in the same key:value pairs.

I've gotten this far:

^((\d+)(<(.+?):(.+?)>)*)(,\d+)(<(.+?):(.+?)>)*$

some valid texts:

• 123131
• 123131, 123131, 1213313
• 12313<key:value>
• 232133<key:value><key:value>,232133<key:value><key:value>

Try this:

^((\d+)(<(.+?):(.+?)>){0,2})(,\s*((\d+)(<(.+?):(.+?)>){0,2}))*$

Depending on which group you don't want to capture, you can change ( ) to (?: ).

Rubular link

Try using this ^(\d+(<.+:.+>){1,2})(,\d+(<.+:.+>){1,2})*$ Hope it helped

Thanks a lot for your responses, but none of them seem to do excactly what I'm looking for. I think maybe the easies thing is to follow OrangeDogs suggestion considering maintainability as well...