查找是否其他休眠实体列（字段成员）在运行时可为空

Question

I have a problem where I would like to find that a field of a hibernate entity(by entityClass ) is representing nullable column or not.

However I want to get it using reliable hibernate meta not like checking for @NotNull annotations and trying to cover any possible scenarios of hibernate considering an entity field nullable or not seems not very reliable.

Appreciate your kind help.

Answer 1

Thanks to @krokodilko I provide the solution code:

protected SessionFactory getSessionFactory() {
    return getEntityManager().getEntityManagerFactory().unwrap(SessionFactory.class);
}

Get nullable metadata

Map<String, Boolean> entityPropNullables = new HashMap<String, Boolean>();
// Provide the class of disired metadata as parameter
ClassMetadata entityMeta = getSessionFactory().getClassMetadata(anEntityClass);
String[] propNames = entityMeta.getPropertyNames();
boolean[] isNullableProps = entityMeta.getPropertyNullability();

if (propNames != null) {
    for (int i = 0; i < propNames.length; i++ ) {
        entityPropNullables.put(propNames[i], isNullableProps[i]);
    }
}