休眠：基于实体类自动创建/更新数据库表

Question

我有以下实体类（在Groovy中）：import javax.persistence.Entityimport javax.persistence.Idimport javax.persistence.GeneratedValueimport javax.persistence.GenerationType@Entitypublic class ServerNode {  @Id  @GeneratedValue(strategy = GenerationType.AUTO)  Long id  String firstName  String lastName}和我的persistence.xml：<?xml version="1.0" encoding="UTF-8"?><persistence xmlns="http://java.sun.com/xml/ns/persistence" version="1.0">    <persistence-unit name="NewPersistenceUnit">        <provider>org.hibernate.ejb.HibernatePersistence</provider>        <properties>            <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/Icarus"/>            <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>            <property name="hibernate.connection.username" value="root"/>            <property name="hibernate.connection.password" value=""/>            <property name="hibernate.archive.autodetection" value="class"/>            <property name="hibernate.show_sql" value="true"/>            <property name="hibernate.format_sql" value="true"/>            <property name="hbm2ddl.auto" value="create"/>        </properties>        <class>net.interaxia.icarus.data.models.ServerNode</class>    </persistence-unit></persistence>和脚本：import javax.persistence.EntityManagerimport javax.persistence.EntityManagerFactoryimport javax.persistence.Persistenceimport net.interaxia.icarus.data.models.ServerNodedef factory = Persistence.createEntityManagerFactory("NewPersistenceUnit")def manager = factory.createEntityManager()manager.getTransaction().begin()manager.persist new ServerNode(firstName: "Test", lastName: "Server")manager.getTransaction().commit()数据库Icarus存在，但当前没有表。我希望Hibernate基于实体类自动创建和/或更新表。我将如何完成？