Customized DB Connection won't rollback on error (Spring Batch : Chunk) - spring-boot

Question

In my first Spring Batch chunk job (I'm a beginner),
I wrote db utility class for using in the chunk step,
since I need to overwrite default connection attributes set by application.properties.
However, it causes rollback problem (never rollback) on errors.
Any advices to improve these logics?
DBUtility class
// Construct
public DBUtility() {
... some business logic to get connection attributes dynamically.
}
#Bean
#BatchDataSource
#Primary
public DriverManagerDataSource getConnection() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(driverNameGottenAbove);
dataSource.setUrl(urlGottenAbove);
dataSource.setUsername(userNameGottenAbove);
dataSource.setPassword(passwordGottenAbove);
return dataSource;
}
#Bean
public DataSourceTransactionManager transactionManager(){
DataSourceTransactionManager dtm = new DataSourceTransationManager(getConnection());
dtm.setRollbackOnCommitFailure(true);
return dtm;
}
#Bean
public JdbcTemplate jdbcTemplate(){
return new JdbcTemplate(getConnection());
}
BatchConfiguration class(chunk)
#SpringBootApplication
#EnableBatchProcessing
#Transactional
public class BatchConfiguration extends DefaultBatchConfigurer {
...
private DBUtility dbUtil;
private DriverManagerDataSource ds;
private PlatformTransactionManager ptm;
// Construct
public BatchConfiguration(){
dbUtil = new DBUtility();
ds = dbUtil.getConnection();
ptm = dbUtil.transactionManager();
}
// Override
#Override
public JobRepository createJobRepository() throws Exception {
JobRepositoryFactoryBean factory = new JobRepositoryFactoryBean();
factory.setDataSource(ds);
factory.setTransactionManager(ptm);
JobRepository repo = factory.getObject();
return repo;
}
#Bean
public Job BatchJob() {
return jobBuilderFactory.get("BatchJob")
.incrementer(new RunIdIncrementer())
.listener(jobListener())
.flow(step1())
.end().build();
}
#Bean
public step step1() {
DefaultTransactionAttribute att = new DefaultTransactionAttribute();
att.setPropagationBehavior(Propagation.REQUIRED.value());
return stepBuilderFactory.get("step1")
.transactionManager(ptm)
.listener(stepListener())
.<Entity, Entity>chunk(COMMIT_INTERVAL)
.reader(reader())
.processor(processore())
.writer(writer())
.readerIsTransactionalQueue()
.transactionAttribute(att)
.build();
}
...
}
Thank you for checking this post.