Java – Any Java libraries out there that validate SQL syntax?

If you're using SQL Server 2008 (or above), then this is the better solution:

SELECT o.OrderId,
       (SELECT MAX(Price)
        FROM (VALUES (o.NegotiatedPrice),(o.SuggestedPrice)) AS AllPrices(Price))
FROM Order o

All credit and votes should go to Sven's answer to a related question, "SQL MAX of multiple columns?"
I say it's the "best answer" because:

1. It doesn't require complicating your code with UNION's, PIVOT's, UNPIVOT's, UDF's, and crazy-long CASE statments.
2. It isn't plagued with the problem of handling nulls, it handles them just fine.
3. It's easy to swap out the "MAX" with "MIN", "AVG", or "SUM". You can use any aggregate function to find the aggregate over many different columns.
4. You're not limited to the names I used (i.e. "AllPrices" and "Price"). You can pick your own names to make it easier to read and understand for the next guy.
5. You can find multiple aggregates using SQL Server 2008's derived_tables like so:
   SELECT MAX(a), MAX(b) FROM (VALUES (1, 2), (3, 4), (5, 6), (7, 8), (9, 10) ) AS MyTable(a, b)

Because Java is a garbage collected language you cannot predict when (or even if) an object will be destroyed. Hence there is no direct equivalent of a destructor.

There is an inherited method called finalize, but this is called entirely at the discretion of the garbage collector. So for classes that need to explicitly tidy up, the convention is to define a close method and use finalize only for sanity checking (i.e. if close has not been called do it now and log an error).

There was a question that spawned in-depth discussion of finalize recently, so that should provide more depth if required...