CascadeType

当Hibernate配置了（JPA注解）

cascade = { CascadeType.PERSIST, CascadeType.MERGE }

调用保存时

session.save(user);

并不能级联保存，因为save不会触发CascadeType.PERSIST。看save的javadoc：

    /**
     * Persist the given transient instance, first assigning a generated identifier. (Or
     * using the current value of the identifier property if the <tt>assigned</tt>
     * generator is used.) This operation cascades to associated instances if the
     * association is mapped with {@code cascade="save-update"}
     *
     * @param object a transient instance of a persistent class
     *
     * @return the generated identifier
     */
    Serializable save(Object object);

save会触发“save-update”和JPA的CascadeType.ALL，并不会触发CascadeType.PERSIST。JPA没有“save-update”的CascadeType，只能使用Hibernate的CascadeType，如果想保存时触发级联：

1. 可以使用JPA的CascadeType.ALL

2. 使用Hibernate的CascadeType.SAVE_UPDATE

@Cascade(CascadeType.SAVE_UPDATE)

触发其他JPA的CascadeType类型，请参见org.hibernate.session源码（或者javadoc）中各个方法，比如：

    /**
     * Make a transient instance persistent. This operation cascades to associated
     * instances if the association is mapped with {@code cascade="persist"}
     * <p/>
     * The semantics of this method are defined by JSR-220.
     *
     * @param object a transient instance to be made persistent
     */
    void persist(Object object);

也就是说该persist方法会触发JPA的CascadeType.PERSIST。

Hibernate支持的CascadeType类型，请见org.hibernate.annotations.CascadeType源码，或者javadoc