No transactional EntityManager available even though one is configured - spring

Question

I'm attempting to transactionally interact with my MySQL database through JPA and Spring data.
config
#Configuration
#EnableJpaRepositories("com.some.models.repositories")
#EnableTransactionManagement
public class MegabotsConfiguration {
#Bean
public EntityManagerFactory entityManagerFactory() {
HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
vendorAdapter.setGenerateDdl(true);
LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
factory.setJpaVendorAdapter(vendorAdapter);
factory.setJpaProperties(additionalProperties());
factory.setPackagesToScan(new String[] { "com.datarank.megabots.models.entities", "com.datarank.megabots.models.repositories" });
factory.setDataSource(dataSource());
factory.afterPropertiesSet();
return factory.getObject();
}
#Bean
public DataSource dataSource(){
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl("jdbc:mysql://localhost:3306/local_ttaggdb");
dataSource.setUsername( "root" );
dataSource.setPassword( "" );
return dataSource;
}
#Bean
public PlatformTransactionManager transactionManager() {
JpaTransactionManager txManager = new JpaTransactionManager();
txManager.setEntityManagerFactory(entityManagerFactory());
return txManager;
}
#Bean
public PersistenceExceptionTranslationPostProcessor exceptionTranslation(){
return new PersistenceExceptionTranslationPostProcessor();
}
Properties additionalProperties() {
Properties properties = new Properties();
properties.setProperty("hibernate.hbm2ddl.auto", "create-drop");
properties.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQL5Dialect");
return properties;
}
//...
}
And here's where I'm attempting to use a transaction:
#Repository
#Scope("prototype")
#Transactional
public class BotWorkQueueRepository {
#Autowired
private BotWorkQueueJPARepository botWorkQueueJPARepository; //this is the jparepository referenced in the #EnableJpaRepositories in config
#PersistenceContext
private EntityManager entityManager;
#Transactional
public synchronized void flagInFlight(final List<BotWorkQueueEntity> botWorkQueueEntities) {
try {
//...set a few properties on entities, then
entityManager.flush(); //Exception thrown here
entityManager.clear();
} catch (Exception e) {
LOGGER.warn("Error making in flight: " + e);
}
}
}
The error I'm getting:
javax.persistence.TransactionRequiredException: No transactional EntityManager available
I've tried most of the solutions for this error posted in SO, with no success.

Answer 1

One thing for starter,
In maven, if you are using the appassembler-maven-plugin, add the following line to your plugin.configuration tag in the POM file.
<extraJvmArguments>-javaagent:"$REPO"/org/aspectj/aspectjweaver/1.8.5/aspectjweaver-1.8.5.jar</extraJvmArguments>
If you are running in an IDE add the following line to your VM arguments.
-javaagent:<PATH TO MAVEN REPO>/org/aspectj/aspectjweaver/1.8.5/aspectjweaver-1.8.5.jar
Where path to maven repo may look something like /User/kenny/.m2/repository/.
$REPO will be auto-resolved in the POM file.