Class ConcurrencyFailureException

java.lang.Object
java.lang.Throwable
java.lang.Exception
java.io.IOException
com.codename1.backend.DataAccessException
com.codename1.backend.ConcurrencyFailureException
public class ConcurrencyFailureException extends DataAccessException

A statement failed because another transaction got there first, and not because anything is wrong with it: the transaction was chosen to end a deadlock, could not be serialized with one that committed before it, or waited for a lock longer than the engine allows.

Named after Spring's, and meant for the same use. The statement is sound and so is the data, so the caller may run its transaction again from the start, or answer that somebody else made the change first. Every other DataAccessException is a failure that running the work again would repeat.

What an engine reports this way depends on the engine and on how it is configured, which is the reason to recognize the whole family and not one code. Two transactions that read a row and then update it with a condition are settled by most engines quietly: the second update changes no rows. An engine that keeps a transaction to the snapshot it first read from refuses the second update instead, and that refusal is this exception. The failures recognized are:

  • PostgreSQL: a serialization failure (SQLSTATE 40001), a deadlock (40P01) and a lock that was not available (55P03).
  • MySQL and MariaDB: a deadlock (error 1213), a lock wait that timed out (1205), a lock refused under NOWAIT (3572), a record that changed since the transaction read it (1020), and any other error of SQLSTATE class 40.

SQLite reports a database that stayed locked past its busy timeout as a plain DataAccessException.

The engine has usually undone the whole transaction by the time this is thrown, and PostgreSQL refuses every further statement in it. So let it leave the @Transactional method, which rolls back for it as for any data access failure, and decide what to do from outside that method. An ORM session reports a database failure as an unchecked exception with this one as its cause; isCauseOf(Throwable) finds it there.

  • Constructor Details

    • ConcurrencyFailureException

      public ConcurrencyFailureException(String message)

    • ConcurrencyFailureException

      public ConcurrencyFailureException(String message, Throwable cause)

  • Method Details

    • isCauseOf

      public static boolean isCauseOf(Throwable failure)
      Whether failure is a concurrency failure or was caused by one, however many exceptions it has been wrapped in since.
      Parameters:
      failure - what was caught; null answers false