Scala Regex to parse URL

Question

I have written this code in scala

val regex = "^(\\w+):\\/{2}(\\w*)\\.?([^\\/]*)([^\\?]*)\\??(.*)?".r
val x = "http://www.google.com/foo/bar/baz.html?x=10&y=20&z=20"
regex.findAllIn(x).matchData.foreach{x=> println(s"${x.group(1)} ${x.group(2)} ${x.group(3)} ${x.group(4)} ${x.group(5)}")

This works very well and I get the desired output of

http 
www 
google.com 
/foo/bar/baz.html 
x=10

However I need a way by which I can loop over the last part and generate strings for all parameters like

x=10
y=20
z=30

I am not clear as to how to extract the last part in a recurring way.

I know there are lots of existing regex to parse URLs on the internet ... but I am trying to understand regex and write my own. (just to learn).

Community · Accepted Answer · 2017-05-23 11:45:02Z

3

If there is a fixed number of parameters, you can just repeat the last group as many times as necessary. For example, if there are always 3 parameters, you would use

"^(\\w+):\\/{2}(\\w+)\\.([^\\/]+)([^\\?]+)\\?([^&]+)&([^&]+)&([^&]+)".r

Otherwise, if the number of parameters varies, there is no regex-only solution for this problem, as it is not possible to extract multiple matches with a single match group. See this answer for more information.

To work around this problem, you can use the following regex

"^(\\w+):\\/{2}(\\w+)\\.([^\\/]+)([^\\?]+)\\?(.*)".r

in which the last group matches all parameters and then split the last match using something like

lastMatch.split("&")

edited May 23, 2017 at 11:45

CommunityBot

11 silver badge

answered Mar 3, 2016 at 21:31

rolve

10.3k4 gold badges58 silver badges78 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Scala Regex to parse URL

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related