Convert String variable to a List [Groovy]

Question

How can I convert this String variable to a List ?

def ids = "[10, 1, 9]"

I tried with: as List and toList();

Solution 1

def l = Eval.me(ids)

Takes the string of groovy code (in this case "[10,1,9]") and evaluates it as groovy. This will give you a list of 3 ints.

Solution 2

def l = ids.split(',').collect{it as int}

Solution 3

Use the built-in JsonSlurper!

Using Eval is dangerous and the string manipulation solution will fail once the data type is changed so it is not adaptable. So it's best to use JsonSlurper.

import groovy.json.JsonSlurper

//List of ints 
def ids = "[10, 1, 9]"
def idList = new JsonSlurper().parseText(ids)

assert 10 == idList[0]

//List of strings 
def ids = '["10", "1", "9"]'
idList = new JsonSlurper().parseText(ids)

assert '10' == idList[0]

Solution 4

This does work for me. And Eval.me will not work in Jenkins groovy script. I have tried.

assert "[a,b,c]".tokenize(',[]') == [a,b,c]

View more solutions

Comments

[Admin]

It is already a list in groovy?

[Reimeus]

This is a List do you want to convert it to a String?

[user2068981]

But when I do ids.each{println it} I have this result : [</br> 1</br> 0</br> ,</br> </br> 1</br> ]</br>

[Sergio Martinez]

I think you want to make a string "10,1,9" into a list [10,1,9]

[user2068981]

def id = ids.substring(1,ids.length()-1) def l= id.split(',').collect{it as int}

[user2068981]

I find this solution but I don't think is the best : def id = ids.substring(1,ids.length()-1) def l= id.split(',').collect{it as int}

[Alexander Suraphel]

jameswiseman.com/blog/2011/01/18/jslint-messages-eval-is-evi‌​l

[chrylis -cautiouslyoptimistic-]

@AlexanderSuraphel Wrong language.

[Alexander Suraphel]

@chrylis Meaning?

[Michael A.]

@AlexanderSuraphel I will answer for him: your article is related to JavaScript (JSLint specifically). But question itself was about Groovy.

[Alexander Suraphel]

@MichaelA. Have you read the linked articles? The problem is not specific to JavaScript's Eval. It's the idea of passing a string to a method that is willing to execute anything. I felt that OP needs to know the risks as well.

[Alexander Suraphel]

I think a better link is stackoverflow.com/questions/86513/…. The ideas discussed apply to any language, not just JavaScript.

[CIsForCookies]

Eval.me didn't work for me as well (Jenkins groovy script). However, your solution gave a wrong result. My str is "['/a/b/c/d@2/e/f/g/h/i/j/k/l.py::m[n-10-3-9-0/8-17-12]',]" (actually I have more entries in the string, but this is the general idea). The tokenize returns only the inner list, i.e. "[n-10-3-9-0/8-17-12]'"

[Vladimir]

The higher scoring answers didn't work for me. This one did.

[Pavol Travnik]

I would not consider using Eval as a safe option though.

[Pavol Travnik]

This should definitely be accepted as right answer.

[Max Cascone]

this works great for me, specifically in Jenkins, and using String instead of Int: files = "'f1','f2'" list = files.split(',').collect{it as String} > list==['f1', 'f2'] > list[1]=='f2'

[Max Cascone]

updating mine after the edit window closed: list = versionFile.split(',').collect() works fine for strings.

[herm]

For me with strings this only works when I have : '["string1", "string2"]' and not with "['string1', 'string2']" running the code from jenkins.

[Alexander Suraphel]

@herm tested it myself and you're right. i've updated the answer