public static void main(String[] args) {
MessageBuilder builder1 = new ConcreteBuilder1();
MessageBuilder builder2 = new ConcreteBuilder2();
Director director = new Director(builder1);
director.constructMessage();
Message msg1 = builder1.retrieveMessage();
System.out.println(msg1);
System.out.println();
director.setBuilder(builder2);
director.constructMessage();
Message msg2 = builder2.retrieveMessage();
System.out.println(msg2);
}
