Read .txt file from workspace groovy script in Jenkins - jenkins

Question

I am new to Jenkins and to groovy scripting, I want to read a .txt file which is located in the workspace of one of the jobs. I am trying to do this way:
myfile = Jenkins.instance.getJob('JobName').workspace.readFileFromWorkspace('file.txt');
But leads to the following error:
groovy.lang.MissingMethodException: No signature of method:
hudson.FilePath.readFileFromWorkspace() is applicable for argument
types: (java.lang.String) values: [file.txt]

Answer 1

Try this:
file = new File("${Jenkins.instance.getJob('JobName').workspace}/file.txt").text

Answer 2

I was struggling to make it work for the pom modules for a file in the workspace, in the
Extended Choice Parameter. Here is my solution with the printlns:
import groovy.util.XmlSlurper
import java.util.Map
import jenkins.*
import jenkins.model.*
import hudson.*
import hudson.model.*
try{
//get Jenkins instance
def jenkins = Jenkins.instance
//get job Item
def item = jenkins.getItemByFullName("The_JOB_NAME")
println item
// get workspacePath for the job Item
def workspacePath = jenkins.getWorkspaceFor (item)
println workspacePath
def file = new File(workspacePath.toString()+"\\pom.xml")
def pomFile = new XmlSlurper().parse(file)
def pomModules = pomFile.modules.children().join(",")
return pomModules
} catch (Exception ex){
println ex.message
}