Develop Reference

Java EE 8 initializing EntityManager during transaction

Im trying to build a simple web service, right now I only have 3 classes, an entity class, a DAO class and a tester class.
My entity class:
#Entity
#Table(name="sales")
public class Sale implements Serializable{
#Id
#Column(name = "idsale_id")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int idsale_id;
#Column(name = "grand_total", nullable = false)
private double grand_total;
public Sale() {
}
public Sale(double grand_total) {
this.grand_total = grand_total;
}
My Database Operations class
#ApplicationScoped
public class DatabaseOperations {
#PersistenceContext(unitName = "owlJPA")
EntityManager em;
#Transactional
public String createSale(double grand_total) {
Sale sale = new Sale(grand_total);
em.persist(sale);
em.flush();
return "Successfully added new entry in DB";
}
}
REST handling code
#RequestScoped
#Path("/hello-world")
public class HelloResource {
#Inject
DatabaseOperations databaseOperations;
#POST
#Produces("text/plain")
#Consumes(MediaType.APPLICATION_JSON)
public String POSTrecieved(JsonObject jsonRaw) {
DatabaseOperations databaseOperations = new DatabaseOperations();
try {
String tempStr = jsonRaw.getJsonObject("newSale").getString("grand_total");
double grand_total = Double.parseDouble(tempStr);
String x = databaseOperations.createSale(grand_total);
return "SUCESSFULLY ADDED NEW SALE, with grand total of: "+x;
}
catch(Exception error){
return error.toString();
}
}
Whenever I try and run a transaction by calling the createSale method, the sale object gets created just fine, but i get a nullPointerException error as my entityManager em is null. But shouldn't my entityManager em already be instantialized as i did #ApplicationScoped?

Hibernate is not using the proxy of a session scope bean spring

I'm using Spring #Scope(value = "session", proxyMode=ScopedProxyMode.TARGET_CLASS) beans for objects that should be shared across a single Http-Session. This will provide for example one "Project" object for each User who is using my application.
To get this working I had to implement an interceptor for Hibernate that is returning the name of the class:
public class EntityProxySupportHibernateInterceptor extends EmptyInterceptor {
private static final long serialVersionUID = 7470168733867103334L;
#Override
public String getEntityName(Object object) {
return AopUtils.getTargetClass(object).getName();
}
}
With this interceptor I can use a Spring CrudRepository to save a Project-entity in the database:
#Repository
public interface ProjectRepository extends CrudRepository<Project, Integer> {
Project findByProjectId(int projectId);
}
Project-entity:
#Component
#Entity
#Table(name = "xxx.projects")
#Scope(value="session", proxyMode=ScopedProxyMode.TARGET_CLASS)
public class Project implements Serializable {
private static final long serialVersionUID = -8071542032564334337L;
private int projectId;
private int projectType;
#Id
#Column(name = "project_id")
public int getProjectId() {
return projectId;
}
public void setProjectId(int projectId) {
this.projectId = projectId;
}
#Column(name = "project_type")
public int getProjectType() {
return projectType;
}
public void setProjectType(int projectType) {
this.projectType = projectType;
}
}
Storing the Project in the database works as expected. I can have a look at the database and the correct values are inserted. Now I have a different entity that I'm creating the same way as the project and that I want to save in the database via a CrudRepository.
Here the problem begins. Hibernate is not inserting the values that I have set. Hibernate always only inserts null into the database. Reading the values in my Spring application is working as expected. I think that Hibernate is not using the proxy of the entity but the underlying blueprint of the object. How can I force Hibernate to use the proxy with the correct values?
Repository:
#Repository("DataInput001Repository")
public interface DataInputRepository extends CrudRepository<DataInput, DataInputId> {}
Entity:
#Component("DataInput001")
#Entity
#Table(name = "xx.data_input_001")
#Scope(value="session", proxyMode=ScopedProxyMode.TARGET_CLASS)
#IdClass(DatanputId.class)
public class DataInput implements Serializable {
private static final long serialVersionUID = -6941087210396795612L;
#Id
#Column(name = "project_id")
private int projectId;
#Column(name = "income")
private String income;
#Column(name = "income_increase")
private String incomeIncrease;
/* Getter + Setter */
}
Service:
#Service("DataInputService001")
public class DataInputServiceImpl implements DataInputService {
#Resource(name = "DataInputMapper001")
DataInputMapperImpl dataInputMapper;
#Resource(name = "DataInput001Repository")
DataInputRepository dataInputRepository;
#Resource(name = "DataInput001")
DataInput datanInput;
#Transactional
public void createDataInput(String json) throws Exception {
dataInputMapper.mapDataInput(json);
dataInputRepository.save(dataInput);
}
public DataInput getDataInput() {
return dataInput;
}
public void setDataInput(DataInput dataInput) {
this.dataInput = dataInput;
}
}

Spring ignores #Transactional annotation

on one of our projects we encountered a problem with Spring ignoring #Transactional annotation and then failing with the following error.
Error starting ApplicationContext. To display the conditions report
re-run your application with 'debug' enabled. 2018-09-13 15:05:18,406
ERROR [main] org.springframework.boot.SpringApplication Application
run failed org.springframework.dao.InvalidDataAccessApiUsageException:
No EntityManager with actual transaction available for current thread
- cannot reliably process 'remove' call; nested exception is javax.persistence.TransactionRequiredException: No EntityManager with
actual transaction available for current thread - cannot reliably
process 'remove' call at
com.my.service.CacheAService.deleteShortTermCache(CacheAService.java:70)
~[classes/:na]
I found similar questions but none of the solutions applied to this case.
#EnableTransactionManagement is present
Transactional class implements an interface
Transactional method is public
Transactional method is not called internally
When I annotate CacheService with #Transactional, everything works again. But I am trying to understand why would Spring ignore #Transactional on CacheAService.
I tried logging Spring's transaction interceptor but there is no mention of CacheA. This is the only related thing that gets logged.
2018-09-13 15:05:18,242 TRACE [main]
org.springframework.transaction.interceptor.TransactionInterceptor
Don't need to create transaction for
[org.springframework.data.jpa.repository.support.SimpleJpaRepository.deleteByValidity]:
This method isn't transactional.
Here is the simplified code. Code is invoked during application startup by Spring's ContextRefreshedEvent.
#Service
public class CacheService implements Cache {
#Autowired
private CacheA cacheAService;
#Autowired
private CacheB cacheBService;
#Override
public void clearCache() {
cacheAService.deleteShortTermCache();
cacheBService.deleteAll();
}
}
public interface CacheA {
void deleteShortTermCache();
}
#Service
#Transactional(readOnly = true)
public class CacheAService implements CacheA {
#Autowired
private CacheARepository cacheARepository;
#Override
#Transactional
public void deleteShortTermCache() {
cacheARepository.deleteByValidity(CacheValidity.SHORT_TERM);
}
}
public interface CacheB {
void deleteAll();
}
#Service
#Transactional(readOnly = true)
public class CacheBService implements CacheB {
#Autowired
private CacheBRepository cacheBRepository;
#Override
#Transactional
public void deleteAll {
cacheBRepository.deleteAll();
}
}
public enum CacheValidity {
SHORT_TERM,
LONG_TERM
}
#Repository
public interface CacheARepository extends JpaRepository<CacheItem, Integer> {
void deleteByValidity(CacheValidity validity);
}
public enum CacheItemKey {
AVAILABLE,
FUTURE,
AVAILABLE_UTM,
FUTURE_UTM,
REGION
}
#Entity
#Table(name = "cache_item")
public class CacheItem {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "cache_item_id_seq")
#SequenceGenerator(name = "cache_item_id_seq", sequenceName = "cache_item_id_seq", allocationSize = 1)
private Integer id;
#Column(nullable = false, unique = true)
#Enumerated(EnumType.STRING)
private CacheItemKey key;
#Column(nullable = false)
private String value;
#Column(name = "date_modified", nullable = false)
#Temporal(TemporalType.TIMESTAMP)
private Date dateModified;
#Column(nullable = false)
#Enumerated(EnumType.STRING)
private CacheValidity validity;
public Integer getId() {
return id;
}
public void setId(final Integer id) {
this.id = id;
}
public CacheItemKey getKey() {
return key;
}
public void setKey(final CacheItemKey key) {
this.key = key;
}
public String getValue() {
return value;
}
public void setValue(final String value) {
this.value = value;
}
public Date getDateModified() {
return dateModified;
}
public void setDateModified(final Date dateModified) {
this.dateModified = dateModified;
}
public CacheValidity getValidity() {
return validity;
}
public void setValidity(final CacheValidity validity) {
this.validity = validity;
}
}
Edit:
After some digging I found this in the logs.
2018-09-14 06:24:11,174 INFO [localhost-startStop-1]
org.springframework.context.support.PostProcessorRegistrationDelegate$BeanPostProcessorChecker
Bean 'cacheAService' of type [com.my.service.CacheAService] is not
eligible for getting processed by all BeanPostProcessors (for example:
not eligible for auto-proxying)

We discovered that this issue was caused by Spring Boot's auto-configuration. Since auto-configuration already setups the Transaction management, our custom configuration of #EnableTransactionManagement broke the instantiation of transaction advisors. Removing of #EnableTransactionManagement from our configuration solves the issue.

Try to use only one Transactional annotation (in class or method). May be, the problem is with #Transactional(readOnly = true), because you transaction isn't readOnly, I can't sure what Transactional annotation is preferred by Spring. Try to use:
#Service
public class CacheAService implements CacheA {
#Autowired
private CacheARepository cacheARepository;
#Override
#Transactional
public void deleteShortTermCache() {
cacheARepository.deleteByValidity(CacheValidity.SHORT_TERM);
}
}
or
#Service
#Transactional
public class CacheAService implements CacheA {
#Autowired
private CacheARepository cacheARepository;
#Override
public void deleteShortTermCache() {
cacheARepository.deleteByValidity(CacheValidity.SHORT_TERM);
}
}

I ran in a familiar situation. For those, who have same problems but the answers won't work.
The #Transactional-annotation works per default only on public-methods. Not on private and not on package-private.
See this question for more information and workarounds -> Does Spring #Transactional attribute work on a private method?

Spring data rest validation for PUT and PATCH running after DB update

I have a SDR project and I am successfully validating the user entity for POST request but as soon as I update an existing entity using either PATCH or PUT the DB is updated BEFORE the validation is executed (the validator is being executed and error is returned but the DB is being updated anyway).
Do I need to setup a separate config for update ? Am I missing an extra step for that?
Entity
#Entity
#JsonIgnoreProperties(ignoreUnknown = true)
public class Member {
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "member_id_gen")
#SequenceGenerator(name = "member_id_gen", sequenceName = "member_id_seq")
#Id
#JsonIgnore
private long id;
#Version
private Integer version;
#NotNull
protected String firstName;
#NotNull
protected String lastName;
#Valid
protected String email;
}
Repository
#RepositoryRestResource(collectionResourceRel = "members", path = "member")
public interface MemberRepository extends PagingAndSortingRepository<Member, Long> {
public Member findByFirstName(String firstName);
public Member findByLastName(String lastName);
}
Validator
#Component
public class BeforeSaveMemberValidator implements Validator {
public BeforeSaveMemberValidator() {}
private String EMAIL_REGEX = "^[a-zA-Z0-9._%+-]+#[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,6}$";
#Override
public boolean supports(Class<?> clazz) {
return Member.class.equals(clazz);
}
#Override
public void validate(Object target, Errors errors) {
Member member = (Member) target;
if(ObjectUtils.isEmpty(member.getFirstName())) {
errors.rejectValue("firstName", "member.firstName.empty");
}
if(ObjectUtils.isEmpty(member.getLastName())) {
errors.rejectValue("lastName", "member.lastName.empty");
}
if(!ObjectUtils.isEmpty(member.getDni()) && !member.getDni().matches("^[a-zA-Z0-9]*$")) {
errors.rejectValue("dni", "member.dni.invalid");
}
if(!ObjectUtils.isEmpty(member.getEmail()) && !member.getEmail().matches(EMAIL_REGEX)) {
errors.rejectValue("email", "member.email.notValid");
}
}
}
BeforeSave service
#Service
#RepositoryEventHandler(Member.class)
public class MemberService {
#HandleBeforeCreate
#HandleBeforeSave
#Transactional
public void beforeCreate(Member member) {
...
}
}

I think you should rename your validator, for example, to MemberValidator then assign it as described here:
#Override
protected void configureValidatingRepositoryEventListener(ValidatingRepositoryEventListener v) {
v.addValidator("beforeCreate", new MemberValidator());
v.addValidator("beforeSave", new MemberValidator());
}
But I suggest you to use Bean validation instead of your custom validators. To use it in SDR project you can inject LocalValidatorFactoryBean, then assign it for 'beforeCreate' and 'beforeSave' events in configureValidatingRepositoryEventListener:
#Configuration
#RequiredArgsConstructor // Lombok annotation
public class RepoRestConfig extends RepositoryRestConfigurerAdapter {
#NonNull private final LocalValidatorFactoryBean validatorFactoryBean;
#Override
public void configureValidatingRepositoryEventListener(ValidatingRepositoryEventListener v) {
v.addValidator("beforeCreate", validatorFactoryBean);
v.addValidator("beforeSave", validatorFactoryBean);
super.configureValidatingRepositoryEventListener(v);
}
}
In this case your SDR will automatically validate payloads of POST, PUT and PATCH requests for all exposed SDR repositories.
See my example for more details.

Why ResponseEntity calls hibernate while lazy loading active

Below is the DAO. I am getting the first UppeningUsers object. Note that here for this function I do not want to return peopleWhoBlockedMe set which is located inside the UppeningUsers..
But in different functions I would like to return that information. Note that Both of them are LAZY fetching. With evict I tried to detach the object but still it did not work.
First of all RESTcontroller is below. Then the DAO code is below. Then two entity descriptions are below.
Question is: I see that until
return new ResponseEntity(returned, HttpStatus.OK);
There is only one query which is the typical select. I do not want hibernate to go and take also UserBlock information of that specific UppeningUser. Because it is not needed for this service response. However even though it is lazy loading for some reason
return new ResponseEntity(returned, HttpStatus.OK);
calls the hibernate. I dont know why in restcontroller still it is connected to the database. I tried evict but didnt work.
The json response is
{"id":7,"peopleWhoBlockedMe":[{"blockedId":7}]}
But I do not want for this function to return this peopleWhoBlockedMe. It can be empty.
PLEASE NOTE that in other service for example I will explictly request this peopleWhoBlockedMe but just for this business logic I do not need this information. So what I can do to prevent this so whenever I actually want to call peopleWhoBlockedMe I can get it. Not automaticly.
#RestController
public class TempController {
#Autowired
UppeningUsersService uppeningUsersService;
#RequestMapping(value = "/testing", method = RequestMethod.GET)
public ResponseEntity<UppeningUsers> getPhotos() {
try {
UppeningUsers returned = uppeningUsersService.getUsersDetailsPartial();
return new ResponseEntity<UppeningUsers>(returned, HttpStatus.OK);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}
This part is the DAO.
#Repository
public class UppeningUsersDAO {
#Autowired
private SessionFactory sessionFactory;
public void setSessionFactory(SessionFactory sf) {
this.sessionFactory = sf;
}
/**
* Get Existing user. Return error if there is not.
* #param incomingUser user who requested access.
* #return returns the guy information. All information.
*/
#Transactional
public UppeningUsers getUserDetails() throws Exception {
Session session = this.sessionFactory.getCurrentSession();
Query query = session.createQuery("from UppeningUsers ");
UppeningUsers returning = (UppeningUsers) query.list().get(0);
session.evict(returning);
return returning;
}
}
The main table is this one..
#Entity
#Table(name = "uppening_users")
#Proxy(lazy = true)
public class UppeningUsers {
#Id
#Column(name = "id")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private
int id;
#OneToMany(mappedBy = "blockedId",cascade =CascadeType.ALL, fetch = FetchType.LAZY)
private Set<UserBlocks> peopleWhoBlockedMe;
public UppeningUsers() {
super();
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public Set<UserBlocks> getPeopleWhoBlockedMe() {
return peopleWhoBlockedMe;
}
public void setPeopleWhoBlockedMe(Set<UserBlocks> peopleWhoBlockedMes) {
this.peopleWhoBlockedMe = peopleWhoBlockedMes;
}
}
Now here is the other table.
#Entity
#Table(name="user_blocks")
#Proxy(lazy = true)
public class UserBlocks {
#Id
#Column(name="id")
#GeneratedValue(strategy= GenerationType.IDENTITY)
int id;
#Column(name = "blocked_id",insertable = false,updatable = false)
private int blockedId;
public int getBlockedId() {
return blockedId;
}
public void setBlockedId(int blockedId) {
this.blockedId = blockedId;
}
}
UPDATE: 2 forgot to add the service
#Service("uppeningUserService")
public class UppeningUsersService {
#Autowired
UppeningUsersDAO uppeningUsersDAO;
public UppeningUsers getUsersDetailsPartial( ) throws Exception {
return uppeningUsersDAO.getUserDetails();
}
}

Jens is right about her sentence. The layer methodology and writing business objects fix the issue. Thank you.