Spring data Jpa Entity not managed Exception when calling refresh

Question

I have a db code jar which I use in different application for accessing db. I am using spring data jpa. I need to call refresh to check for change in row in db from some other application. Here How I implement it. My StudentRepository interface:

public interface StudentRepository extends JpaRepository<StudentEntity, Integer>, StudentRepositoryCustom {}

My StudentRespositoryCustom interface

public interface StudentRepositoryCustom {
    void detach(StudentEntity studentEntity);
    void refresh(StudentEntity studentEntity);}

My StudentRepositoryCustomImpl class

public class StudentRepositoryImpl implements StudentRepositoryCustom {

@PersistenceContext
EntityManager entityManager;

@Override
@Transactional
public void detach(StudentEntity studentEntity) {
    entityManager.detach(studentEntity);
}

@Override
@Transactional
public void refresh(StudentEntity studentEntity) {
    entityManager.refresh(studentEntity);
}}

My Test

@Test
public void refreshTest(){
    StudentEntity studentEntity = studentRepository.findOne(6);
    studentRepository.refresh(studentEntity);
}

But it throws this exception:

org.springframework.dao.InvalidDataAccessApiUsageException: Entity not managed; nested exception is java.lang.IllegalArgumentException: Entity not managed

at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:384)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:492)
at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:59)

This line in hibernate-core-5.2.1.final SessionImpl class return null

EntityEntry entry = persistenceContext.getEntry( object );

It should return entity I think.

My persistence.xml file is

<persistence-unit name="testPersitanceUnit" transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
    <class>com.sample.dao.gen.StudentEntity</class>
    <properties>
        <property name="hibernate.archive.autodetection" value="class"/>
        <property name="hibernate.show_sql" value="true"/>
        <property name="hibernate.format_sql" value="true"/>
        <property name="hbm2ddl.auto" value="update"/>
        <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect" />
        <property name="hibernate.enable_lazy_load_no_trans" value="true" />
    </properties>
</persistence-unit>

My spring db config file is

 <jpa:repositories base-package="com.sample.dao.repos"
                  entity-manager-factory-ref="entityManagerFactory" transaction-manager-ref="transactionManager"/>

<!-- Enable the component scan (auto wiring etc) for the following package -->
<context:component-scan base-package="com.sample.dao" />

<!-- Make sure the following is specified to enable transaction  -->
<tx:annotation-driven />
<bean class="org.springframework.orm.jpa.JpaTransactionManager" id="transactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>

<!--  This defines the entity manager factory with some custom properties -->
<bean id='entityManagerFactory' primary="true" class='org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean'>
    <property name="persistenceUnitName" value="testPersitanceUnit"/>
    <property name='dataSource' ref='dataSource' />
    <property name="packagesToScan" value="com.sample.dao" />
enter code here

Answer 1

try

public StudentEntity refresh(StudentEntity studentEntity) {
    StudentEntity managedEntity = entityManager.find(StudentEntity.class, studentEntity.getId());
    entityManager.refresh(managedEntity);
    return managedEntity;
}}

The reason you are having the problem is that in your test, your studentEntity was passed outside of the transaction (findOne), and therefore no longer managed. When it gets passed into a new transaction (refresh) it is not managed, and so throws this error.

Alternatively, if the original refresh is desired behavior, you can wrap your entire test in a transaction, that should maintain management of your test object.