Can groovy string interpolation be nested?

Question

I'm trying to add parameter in Jenkins groovy shell script, then wonder if groovy string interpolation can be used nested way like this.

node{

    def A = 'C'
    def B = 'D'
    def CD = 'Value what I want'

    sh "echo ${${A}${B}}"
}

Then what I expected is like this;

'Value what I want'

as if I do;

sh "echo ${CD}"

But it gives some error that $ is not found among steps [...]

Is it not possible?

Answer 1

Like this?

import groovy.text.GStringTemplateEngine

// processes a string in "GString" format against the bindings    
def postProcess(str, Map bindings) {
 new GStringTemplateEngine().createTemplate(str).make(bindings).toString()
}

node{

    def A = 'C'
    def B = 'D'

    def bindings = [
      CD: 'Value what I want'
    ]

    // so this builds the "template" echo ${CD}
    def template = "echo \${${"${A}${B}"}}"​
    // post-process to get: echo Value what I want
    def command = postProcess(template, bindings)

    sh command
}  

Answer 2

In regard to the accepted answer, if you're putting values in a map anyway then you can just interpolate your [key]:

def A = 'C'
def B = 'D'
def bindings = [ CD: 'Value what I want' ]

bindings["${A}${B}"] == 'Value what I want'