/* New RegEx */ def artifactVersion = '0.2034.111' def buildNumber = '1' if (artifactVersion =~ /(^|\.)0[0-9]{1,}($|\.|\-)/) { buildNumber = String.valueOf(buildNumber).padLeft(2, '0') } println(buildNumber) /* Old RegEx */ def artifactVersion1 = '0.2034.111' def buildNumber2 = '1' if (artifactVersion1 =~ /0[0-9]{1,}\./) { buildNumber2 = String.valueOf(buildNumber2).padLeft(2, '0') } println(buildNumber2)