How to extract substring in Groovy?

Question

I have a Groovy method that currently works but is real ugly/hacky looking:

def parseId(String str) {
    System.out.println("str: " + str)
    int index = href.indexOf("repositoryId")
    System.out.println("index: " + index)
    int repoIndex = index + 13
    System.out.println("repoIndex" + repoIndex)
    String repoId = href.substring(repoIndex)
    System.out.println("repoId is: " + repoId)
}

When this runs, you might get output like:

str: wsodk3oke30d30kdl4kof94j93jr94f3kd03k043k?planKey=si23j383&repositoryId=31850514
index: 59
repoIndex: 72
repoId is: 31850514

As you can see, I'm simply interested in obtaining the repositoryId value (everything after the = operator) out of the String. Is there a more efficient/Groovier way of doing this or this the only way?

Use a regular expression to capture the pattern you're looking for — Jeff Storey, Jul 31 '14 at 16:22

score 21 · Answer 1 · answered Jul 31 '14 at 16:24

21

There are a lot of ways to achieve what you want. I'll suggest a simple one using split:

sub = { it.split("repositoryId=")[1] }

str='wsodk3oke30d30kdl4kof94j93jr94f3kd03k043k?planKey=si23j383&repositoryId=31850514'

assert sub(str) == '31850514'

answered Jul 31 '14 at 16:24

Will

14,348
1
42
44

I get an error: **no such property sub for class: org.gradle.api.internal.project.DefaultProject_Decorated** – IgorGanapolsky Aug 02 '16 at 22:06
1

@IgorGanapolsky are you running it from a script? try adding a `def` in front of `sub`. – Will Aug 03 '16 at 12:15
@Will, how do i get only the say next number and not the trailing ones after that? your solution is returning everything after the keyword. e.g. i have the String, "Request ID for the current retrieve task: 09Sg00000052eIJEAY [sf:retrieve] Waiting for server to finish processing the request...". I am trying to get only "09Sg00000052eIJEAY". I know i have to modify the index. But i can't figure so far – OK999 Jul 25 '17 at 15:52
Got it!!! def sub = { it.split("current retrieve task: ")[1][0..18] } .... Upvoted the answer :) – OK999 Jul 25 '17 at 15:59

Jeff Storey · Answer 2 · 2014-07-31T16:40:20.700

16

Using a regular expression you could do

def repositoryId = (str =~ "repositoryId=(.*)")[0][1]

The =~ is a regex matcher

edited Jul 31 '14 at 16:40

answered Jul 31 '14 at 16:28

Jeff Storey

56,312
72
233
406

the `=` is missing :) – injecteer Jul 31 '14 at 16:37

score 2 · Answer 3 · answered Jul 31 '14 at 16:36

2

or a shortcut regexp - if you are looking only for single match:

String repoId = str.replaceFirst( /.*&repositoryId=(\w+).*/, '$1' )

answered Jul 31 '14 at 16:36

injecteer

20,038
4
45
89

Foxy Fox · Answer 4 · 2023-07-13T19:32:09.063

All the answers here contains regular expressions, however there are a bunch of string methods in Groovy.

String Function	Sample	Description
contains	myStringVar.contains(substring)	Returns true if and only if this string contains the specified sequence of char values
equals	myStringVar.equals(substring)	This is similar to the above but has to be an exact match for the check to return a true value
endsWith	myStringVar.endsWith(suffix)	This method checks the new value contains an ending string
startsWith	myStringVar.startsWith(prefix)	This method checks the new value contains an starting string
equalsIgnoreCase	myStringVar.equalsIgnoreCase(substring)	The same as equals but without case sensitivity
isEmpty	myStringVar.isEmpty()	Checks if myStringVar is populated or not.
matches	myStringVar.matches(substring)	This is the same as equals with the slight difference being that matches takes a regular string as a parameter unlike equals which takes another String object
replace	myStringVar.replace(old,new)	Returns a string resulting from replacing all occurrences of oldChar in this string with newChar
replaceAll	myStringVar.replaceAll(old_regex,new)	Replaces each substring of this string that matches the given regular expression with the given replacement
split	myStringVar.split(regex)	Splits this string around matches of the given regular expression

How to extract substring in Groovy?

4 Answers4