I have updated the hiberate version from 4.0.1.Final to 5.0.7.Final . (porting from Jboss 7 to Wildfly 10)
*Problem:* The hibernate framwork uses hibernate_sequence for the id generation instead of mySequence.
*Hibernate configuration:* In order to maintain the backward compatibility, hibernate.id.new_generator_mappings is configured as false value.
*Entity configuration:* The id field is annotated with the following JPA API:
{code:java} @Id @GeneratedValue(strategy = GenerationType.AUTO, generator = "myGenerator") @SequenceGenerator(name = "myGenerator", sequenceName = "MY_GENERATOR_SEQ") @Column(name="ID") private Long id; {code}
*DB configuration:* The MY_GENERATOR_SEQ sequence is defined with the "INCREMENT BY 1" option.
The problem occurs for both H2 and Oracle DB.
{quote}*QUESTION:* I have analyzed the implementation and I don't know if it could be a BUG of Hibernate or any possible bad configuration i did for the backward compatibility???{quote}
*Analysis:* Hibernate during server startup gets some initialization: SequenceStyleGenerator.configure method defines the QualifiedName sequenceName as "hibernate_sequence", because it tried to get the value from the Properties params. At this point I noticed that the MY_GENERATOR_SEQ sequenceName was present into the Properties params at runtime with the "sequence" key (sequence=MY_GENERATOR_SEQ) but the retrieve strategy (determineSequenceName) needs the "sequence_name" as key. So the key used to set the sequence name into the Properties params is from the deprecated class org.hibernate.id.SequenceGenerator.SEQUENCE because of hibernate.id.new_generator_mappings=false, but the SequenceStyleGenerator class needs the org.hibernate.id.enhanced.SequenceStyleGenerator.SEQUENCE_PARAM key in order to get "MY_GENERATOR_SEQ".
Potential solutions: 1. set on SequenceGenerator allocationSize=1 (without setting hibernate.id.new_generator_mappings=false) 2. create the sequence MY_GENERATOR_SEQ on the DB with INCREMENT BY 50 (without setting hibernate.id.new_generator_mappings=false)
Both the solutions are not applicable into my context. So the only applicable "solution" is this one: Extend the Dialect used for Oracle and H2 and override the getNativeIdentifierGeneratorClass method in this way: {code:java} @Override public Class getNativeIdentifierGeneratorClass() { if ( getIdentityColumnSupport().supportsIdentityColumns() ) { return IdentityGenerator.class; } else { //From hibernate-core 5.0. 6 7 .Final, org.hibernate.dialect.Dialect //the original return value was org.hibernate.id.enhanced.SequenceStyleGenerator.class return SequenceGenerator.class; } } {code} |
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