java.sql.Connection.TRANSACTION_SERIALIZABLE, java.sql.Connection.TRANSACTION_REPEATABLE_READ, java.sql.Connection.TRANSACTION_READ_COMMITTED, and java.sql.Connection.TRANSACTION_READ_UNCOMMITTED transaction isolations are available from a Derby database.
TRANSACTION_READ_COMMITTED is the default isolation level.
Changing the current isolation for the connection with setConnection commits the current transaction and begins a new transaction, per the JDBC standard.