Converting a gstringimpl to java.lang.string in a Jenkinsile - jenkins

Question

I have a pipeline which takes a persistent string parameter input. The pipeline then checks whether the parameter value is present in a list.
The problem is that the persisted string is of type gstringimpl, and the list items are java.lang.string type. When I use the .contains() method, even though the value is in the list, it won't return true, which I believe is due to the different data types.
I've tried everything online, including the toString() method but I can't get it to work. I'm attaching my code below.
String ver = ""
pipeline {
agent {
docker{
image 'registry/abc/builder:0.1.5'
args '-t -d -v maven-m2-cache:/home/node/.m2'
}
}
parameters {
persistentString(name: 'Version', defaultValue: '8.4.7.8', description: 'Version to build', successfulOnly: false)
}
stages {
stage('Analyze Parameter'){
steps{
script{
ver = "${Version}".toString()
}
}
}
stage('Build'){
steps{
script{
def version_list1 = ['8.4.7.8','8.3.7.9','8.5.4.7']
if (version_list1.contains("${ver}")){
println("build version branch")
} else {
println("${ver}")
println("${ver}".getClass())
println(version_list1[0])
println(version_list1[0].getClass())
println("build master branch")
}
}
}
}
}
}
The pipeline always goes into the else block and prints the following:
8.4.7.8
class org.codehaus.groovy.runtime.GStringImpl
8.4.7.8
java.lang.string
build master branch

Answer 1

Don't use String interpolation to resolve Parameters. Instead directly access it like params.PARAM_NAME, example below.
script{
def version_list1 = ['8.4.7.8','8.3.7.9','8.5.4.7']
if (version_list1.contains(params.Version)){
println("build version branch")
} else {
println("build master branch")
}
}