#Transactional annotation does not rollback - spring

Question

I struggle to get #Transactional to work in combination with NamedParameterJdbcTemplate.batchUpdate() in an enterprise application. It was hard to debug, so I built a working minimal example in Spring Boot just to check my approach. In the minimal example I use Spring Boot 2.4.0 with the H2 Database.
This is the DatabaseContext:
#Configuration
public class DatabaseContext {
#Bean
public EmbeddedDatabase embeddedDatabase() {
EmbeddedDatabase db = new EmbeddedDatabaseBuilder()
.setType(EmbeddedDatabaseType.H2)
.addScript("import.sql")
.build();
return db;
}
#Bean
public NamedParameterJdbcTemplate namedParameterJdbcTemplate(EmbeddedDatabase embeddedDatabase) {
return new NamedParameterJdbcTemplate(embeddedDatabase);
}
#Bean
public PlatformTransactionManager txManager(EmbeddedDatabase embeddedDatabase) {
return new DataSourceTransactionManager(embeddedDatabase);
}
}
This is the repository of the minimal example:
#Repository
public class TransactionalRepositoryImpl implements TransactionalRepository {
#Autowired
private NamedParameterJdbcTemplate namedParameterJdbcTemplate;
#Override
#Transactional
public List<TransactionalEntity> store(List<TransactionalEntity> entities) {
String insertSql = "insert into entities "
+ " ( "
+ " firstName, "
+ " lastName "
+ " ) "
+ " values" + " ("
+ " :firstName, "
+ " :lastName "
+ " ) ";
List<MapSqlParameterSource> batchOfInserts = new ArrayList<>();
for (TransactionalEntity entity : entities) {
MapSqlParameterSource params = new MapSqlParameterSource();
params.addValue("firstName", entity.getFirstName());
params.addValue("lastName", entity.getLastName());
batchOfInserts.add(params);
}
int[] insertCounts = new int[0];
if (batchOfInserts.size() > 0) {
insertCounts = namedParameterJdbcTemplate.batchUpdate(insertSql, batchOfInserts.toArray(new MapSqlParameterSource[0]));
}
System.out.println(Arrays.toString(insertCounts));
return entities;
}
}
I call the repository like this:
TransactionalEntity entity1 = new TransactionalEntity("Foo", "Bar");
TransactionalEntity entity2 = new TransactionalEntity("Foo", "Bar");
//TransactionalEntity entity2 = new TransactionalEntity("Zoo", "Car");
transactionalRepository.store(ImmutableList.of(entity1, entity2));
This should fail with DuplicateKeyException for entity2, as there is a primary key in H2 that prevents inserts with the same values more than once. It does fail for entity2, and because of the #Transactional annotation, also entity1 is not in H2 afterwards. If I then remove #Transactional from the repository, the same exception is thrown, but entity1 is in H2. So far so good, this is exactly as expected.
Now to my actual enterprise application. It is a big monolithic multi-module Spring app (not Spring Boot). Instead of H2, it uses Postgres. It is naturally much more complex than my minimal example. However a few key things are actually pretty much the same. The repository setup is basically identical to my minimal example, and so is the DatabaseContext (it uses DataSource instead of EmbeddedDatabase though). The context is imported into another #Configuration class using #Import. That class is annotated with #EnableAspectJAutoProxy and has a #ComponentScan that covers the repository. It itself is imported by a third #Configuration class public class WebApplicationConfig extends DelegatingWebMvcConfiguration.
When I now trigger an action similar to my minimal example, causing a DuplicateKeyException, I find that the first of the two values still has been inserted into the database despite the #Transactional annotation, which of course is not as expected.
I played around with a few things. I annotated the context with #EnableTransactionManagement(proxyTargetClass = true). I even tried to get the transaction working programmatically instead, using
#Bean
public TransactionTemplate txTemplate(PlatformTransactionManager txManager){
return new TransactionTemplate(txManager);
}
without success.
I am just a bit out of ideas how to debug this any further, so I am hoping for input here. Thank you :)