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javapostgresqllambdacastinghstore

Postgres hstore casting works wrong

The following line works incorrect with Java 8. (Map<Integer, BigDecimal>) resultSet.getObject("hstore_field");

hstore key and value are stored as text in the Postgres DB. Despite the fact the object received from resultSet is casted to Map<Integer, BigDecimal> and no warnings/errors received during compilation time, data persisted in HashMap is of type <String, String>. I have tested with instanceof BigDecimal and got false. More interesting lambda way failed at runtime when doing

hstoreMap.foreach((k,v)-> System.out.println(k + " " +v));

So,the problem is clear - casting does not work this way. Therefore I casted to Map and then converted map to required type. Anyway, is this kind of bug?

Solution

  • I'm not 100% sure, but here's what I was able to find for you:

    http://www.postgresql.org/message-id/4FAB8796.40904@nitorcreations.com

    It looks like hstore support is still limited to HashMap<String, String> wrapper object. I would not call it a bug anyway.