<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-mapping>
    <class entity-name="test_entity" table="test_entity">
        <id name="id" type="java.lang.Long" length="64" unsaved-value="null">
            <generator class="identity" />
        </id>
        <property type="java.lang.String" name="username" column="username"/>

        <property name="password" type="java.lang.String" column="password"/>
    </class>
</hibernate-mapping>

//针对 spring data jpa 获取session
@Autowired
private EntityManager entityManager;
Session session = entityManager.unwrap(Session.class);

StandardServiceRegistry serviceRegistry = session.getSessionFactory().getSessionFactoryOptions().getServiceRegistry();
MetadataSources metadataR = new MetadataSources(serviceRegistry);
//in 是通过xml文件得到的 ,可以通过模板生成xml,xml即为动态实体的hbm.xml
metadataR.addInputStream(in);

Metadata metadata   =     metadataR.buildMetadata();
SchemaUpdate schemaUpdate = new SchemaUpdate();
schemaUpdate.execute(EnumSet.of(TargetType.DATABASE),metadata,serviceRegistry);