Compensating transaction in JTA

compensating-tx-in-jta.java

class Service {
    @Inject
    EntityManager entityManager;

    @Inject
    CompensationManager compensationManager;

    @Inject
    Session session; // E.g. Neo4j session

    @Transactional // Begins a JTA transaction
    @Compensatable // Begins a compensating transaction
    void method() {
        // Enlists compensations XA resource to the JTA transaction
        // Somehow lets @Compensatable interceptor know to not complete compensating transaction
        compensationManager.joinJtaTransaction();
        entityManager.persist("...");
        CompensatableAction
            // Registers work action and its compensating action
            .addWork(() -> session.run("<< Write to the db >>"), () -> session.run("<< Undo what you've wrote >>"))
            // Executes work and enlists participant with compensating action to the compensating transaction
            .execute();
    }
}

class CompensationsXAResource implements XAResource, LastResource {
    int prepare(Xid xid) {
        return XA_OK;
    }
    
    void commit(Xid xid, boolean b) {
        try {
            BAControllerFactory.getInstance().completeBusinessActivity(false);
        } catch (Exception e) {
            throw new XAException(XAException.XA_RBROLLBACK);
        }
    }
    
    void rollback(Xid xid) {
        try {
            BAControllerFactory.getInstance().cancelBusinessActivity();
        } catch (Exception e) {
            throw new XAException(XAException.XA_RBROLLBACK);
        }
    }
    
    // The rest of XAResource methods
}