call library functions in jenkinsfile

script.groovy

@@ -1,19 +1,5 @@
-def buildJar() {
-    echo "building the application..."
-    sh 'mvn package'
-} 
-
-def buildImage() {
-    echo "building the docker image..."
-    withCredentials([usernamePassword(credentialsId: 'docker-hub-repo', passwordVariable: 'PASS', usernameVariable: 'USER')]) {
-        sh 'docker build -t nanajanashia/demo-app:jma-2.0 .'
-        sh "echo $PASS | docker login -u $USER --password-stdin"
-        sh 'docker push nanajanashia/demo-app:jma-2.0'
-    }
-} 
-
 def deployApp() {
     echo 'deploying the application...'
-} 
+}
 
-return this
+return this