jodd-db/src/main/java/jodd/db/oom/dao/GenericDao.java
protected <E> boolean isPersistent(final DbEntityDescriptor<E> ded, final E entity) {
		final Object key = ded.getIdValue(entity);

		if (key == null) {
			return false;
		}
		if (key instanceof Number) {
			final long value = ((Number)key).longValue();

			if (value == 0) {
				return false;
			}
		}
		return true;
	}
protected <E> boolean isPersistent(final DbEntityDescriptor<E> ded, final E entity) {
		final Object key = ded.getIdValue(entity);

		if (key == null) {
			return false;
		}
		if (key instanceof Number) {
			final long value = ((Number)key).longValue();

			if (value == 0) {
				return false;
			}
		}
		return true;
	}
Returns <code>true</code> if entity is persistent.