How do you load a groovy file and execute it

If your Jenkinsfile and groovy file in one repository and Jenkinsfile is loaded from SCM you have to do:

Example.Groovy

def exampleMethod() {
    //do something
}

def otherExampleMethod() {
    //do something else
}
return this

JenkinsFile

node {
    def rootDir = pwd()
    def exampleModule = load "${rootDir}@script/Example.Groovy "
    exampleModule.exampleMethod()
    exampleModule.otherExampleMethod()
}

If you have pipeline which loads more than one groovy file and those groovy files also share things among themselves:

JenkinsFile.groovy

def modules = [:]
pipeline {
    agent any
    stages {
        stage('test') {
            steps {
                script{
                    modules.first = load "first.groovy"
                    modules.second = load "second.groovy"
                    modules.second.init(modules.first)
                    modules.first.test1()
                    modules.second.test2()
                }
            }
        }
    }
}

first.groovy

def test1(){
    //add code for this method
}
def test2(){
    //add code for this method
}
return this

second.groovy

import groovy.transform.Field
@Field private First = null

def init(first) {
    First = first
}
def test1(){
    //add code for this method
}
def test2(){
    First.test2()
}
return this

You have to do checkout scm (or some other way of checkouting code from SCM) before doing load.

Thanks @anton and @Krzysztof Krasori, It worked fine if I combined checkout scm and exact source file

Example.Groovy

def exampleMethod() {
    println("exampleMethod")
}

def otherExampleMethod() {
    println("otherExampleMethod")
}
return this

JenkinsFile

node {
    // Git checkout before load source the file
    checkout scm

    // To know files are checked out or not
    sh '''
        ls -lhrt
    '''

    def rootDir = pwd()
    println("Current Directory: " + rootDir)

    // point to exact source file
    def example = load "${rootDir}/Example.Groovy"

    example.exampleMethod()
    example.otherExampleMethod()
}