Hibernate query.list() method is returning empty list instead of null value

When there are no rows, both query.list() and criteria.list() are returning empty list instead of a n开发者_开发百科ull value.

What is the reason behind this?

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The reason is not to force null checks in client code, in consistency with Effective Java 2nd Edition, Item 43: Return empty arrays or collections, not nulls.

This makes the client code simpler and less error-prone (and most likely the method implementation as well).

The null-return idiom is likely a holdover from the C programming language, in which array lengths are returned separately from actual arrays. In C, there is no advantage to allocating an array if zero is returned as the length.

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It is consistant: a list is returned with all results, whether there are any or not.