Not allowed to create transaction on shared EntityManager - use Spring transactions or EJB CMT

This post is in continuation of https://stackoverflow.com/questions/17856917/jpa-how-to-get-the-value-from-database-after-persist

When I execute the following I am getting following exception, how can I resolve this?

Not allowed to create transaction on shared EntityManager - use Spring 
transactions or EJB CMT

DAOImpl code

public void create(Project project) {
        entityManager.persist(project);
        entityManager.getTransaction().commit();
        project = entityManager.find(Project.class, project.getProjectId());
        entityManager.refresh(project);
        System.out.println("Id    -- " + project.getProjectId());
            System.out.println("no -- " + project.getProjectNo());
    }

applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">

	<bean id="DataSource"
		class="org.springframework.jdbc.datasource.DriverManagerDataSource">
		<property name="username" value="scott" />
		<property name="password" value="tiger" />
		<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" />
		<property name="url" value="jdbc:oracle:thin:@myserver:1521:ORCL" />
	</bean>

	<bean id="entityManagerFactory"
		class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
		<property name="dataSource" ref="DataSource" />
		<property name="packagesToScan" value="test.entity" />
		<property name="jpaVendorAdapter">
			<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
				<property name="showSql" value="true" />
				<property name="generateDdl" value="false" />
				<property name="databasePlatform" value="org.hibernate.dialect.Oracle10gDialect" />
			</bean>
		</property>
	</bean>

	<context:component-scan base-package="test.net" />
               
    <tx:annotation-driven transaction-manager="transactionManager"/> 
    
     <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>         
                           
     <context:annotation-config/>

</beans>

I guess the problem here is that although you have defined the bean for the transaction manager, you haven't annotated the create() method with @Transactional which enables spring transactions.

Also remove the entityManager.getTransaction().commit(); statement as now all the transaction management will be handled by spring, if you leave the statement as it is then you will get the same error again.

Injecting EntityManagerFactory instead of EntityManager and javax.transaction.Transactional annotation on method solved my issue as shown below.

//Autowire EntityManagerFactory
@PersistenceUnit(unitName = "readwrite.config")
private EntityManagerFactory entityManagerFactory;


//Use below code on create/update
EntityManager entityManager = entityManagerFactory.createEntityManager();

entityManager.getTransaction().begin();
if (!ObjectUtils.isEmpty(entity) && !entityManager.contains(entity)) {
   entityManager.persist(entity);
   entityManager.flush();
}
entityManager.getTransaction().commit();

you need to remove entityManager.getTransaction().begin() statement and annotate method using @Transactional which enables spring transactions