Jenkins : Change JVM Options in all Maven tasks of Freestyle Jobs

This script find all Maven Tasks registered in freestyle jobs and replace JVM Options by a new value.

import hudson.model.*
import hudson.maven.*
import hudson.tasks.*

def newJvmOptions="-Xshare:auto -Xms64m -Xmx512m -XX:MaxPermSize=256M"

// For each project
for(item in Hudson.instance.allItems) {
  if(item instanceof FreeStyleProject) {
    println("JOB : ";
    // Find current recipients defined in project
    println(">FREESTYLE PROJECT");
    for (builder in{
      println(">> "+builder);
      if (builder instanceof Maven) {
        println(">>MAVEN BUILDER");
        println(">>TARGETS : "+builder.targets);
        println(">>NAME : "+builder.mavenName);
        println(">>POM : "+builder.pom);
        // .properties is overridden by groovy
        println(">>PROPERTIES : "+builder.@properties);
        println(">>JVM-OPTIONS : "+builder.jvmOptions);
        println(">>USE PRIVATE REPO : "+builder.usePrivateRepository);
        println(">>USER SETTINGS : "+builder.settings);
        println(">>GLOBAL SETTINGS : "+builder.globalSettings);
        def newBuilder = new Maven(builder.targets,builder.mavenName,builder.pom,builder.@properties,newJvmOptions,builder.usePrivateRepository,builder.settings,builder.globalSettings);