I am trying to do something like
https://wiki.eclipse.org/EclipseLink/Release/2.5/JPA21#CDI_Entity_Listeners
but non of my injections are working.
Does Entity Listener doesn't inject CDI dependencies ?
Do we have to do something different.
public class EntityListener {
#Inject
private UserUtility userUtility;
#PrePersist
public void prePersist(Object object) {
logger.log("prepersist", object);
}
#PostPersist
public void postPersist(Object object){
object.createUser(userUtility.getLoggedInUser())
}
}
But my userUtility is always null, I am using userUtility in different places in my project and It is properly injected.
Just not in here.
Any clues, Please help me.
Related
I want to read text data fixtures (CSV files) at the start on my application and put it in my database.
For that, I have created a PopulationService with an initialization method (#PostConstruct annotation).
I also want them to be executed in a single transaction, and hence I added #Transactional on the same method.
However, the #Transactional seems to be ignored :
The transaction is started / stopped at my low level DAO methods.
Do I need to manage the transaction manually then ?
Quote from legacy (closed) Spring forum:
In the #PostConstruct (as with the afterPropertiesSet from the InitializingBean interface) there is no way to ensure that all the post processing is already done, so (indeed) there can be no Transactions. The only way to ensure that that is working is by using a TransactionTemplate.
So if you would like something in your #PostConstruct to be executed within transaction you have to do something like this:
#Service("something")
public class Something {
#Autowired
#Qualifier("transactionManager")
protected PlatformTransactionManager txManager;
#PostConstruct
private void init(){
TransactionTemplate tmpl = new TransactionTemplate(txManager);
tmpl.execute(new TransactionCallbackWithoutResult() {
#Override
protected void doInTransactionWithoutResult(TransactionStatus status) {
//PUT YOUR CALL TO SERVICE HERE
}
});
}
}
I think #PostConstruct only ensures the preprocessing/injection of your current class is finished. It does not mean that the initialization of the whole application context is finished.
However you can use the spring event system to receive an event when the initialization of the application context is finished:
public class MyApplicationListener implements ApplicationListener<ContextRefreshedEvent> {
public void onApplicationEvent(ContextRefreshedEvent event) {
// do startup code ..
}
}
See the documentation section Standard and Custom Events for more details.
As an update, from Spring 4.2 the #EventListener annotation allows a cleaner implementation:
#Service
public class InitService {
#Autowired
MyDAO myDAO;
#EventListener(ContextRefreshedEvent.class)
public void onApplicationEvent(ContextRefreshedEvent event) {
event.getApplicationContext().getBean(InitService.class).initialize();
}
#Transactional
public void initialize() {
// use the DAO
}
}
Inject self and call through it the #Transactional method
public class AccountService {
#Autowired
private AccountService self;
#Transactional
public void resetAllAccounts(){
//...
}
#PostConstruct
private void init(){
self.resetAllAccounts();
}
}
For older Spring versions which do not support self-injection, inject BeanFactory and get self as beanFactory.getBean(AccountService.class)
EDIT
It looks like that since this solution has been posted 1.5 years ago developers are still under impression that if a method,
annotated with #Transactional, is called from a #PostContruct-annotated method invoked upon the Bean initialization, it won't be actually executed inside of Spring Transaction, and awkward (obsolete?) solutions get discussed and accepted instead of this very simple and straightforward one and the latter even gets downvoted.
The Doubting Thomases :) are welcome to check out an example Spring Boot application at GitHub which implements the described above solution.
What actually causes, IMHO, the confusion: the call to #Transactional method should be done through a proxied version of a Bean where such method is defined.
When a #Transactional method is called from another Bean, that another Bean usually injects this one and invokes its proxied (e.g. through #Autowired) version of it, and everything is fine.
When a #Transactional method is called from the same Bean directly, through usual Java call, the Spring AOP/Proxy machinery is not involved and the method is not executed inside of Transaction.
When, as in the suggested solution, a #Transactional method is called from the same Bean through self-injected proxy (self field), the situation is basically equivalent to a case 1.
#Platon Serbin's answer didn't work for me. So I kept searching and found the following answer that saved my life. :D
The answer is here No Session Hibernate in #PostConstruct, which I took the liberty to transcribe:
#Service("myService")
#Transactional(readOnly = true)
public class MyServiceImpl implements MyService {
#Autowired
private MyDao myDao;
private CacheList cacheList;
#Autowired
public void MyServiceImpl(PlatformTransactionManager transactionManager) {
this.cacheList = (CacheList) new TransactionTemplate(transactionManager).execute(new TransactionCallback(){
#Override
public Object doInTransaction(TransactionStatus transactionStatus) {
CacheList cacheList = new CacheList();
cacheList.reloadCache(MyServiceImpl.this.myDao.getAllFromServer());
return cacheList;
}
});
}
The transaction part of spring might not be initialized completely at #PostConstruct.
Use a listener to the ContextRefreshedEvent event to ensure, that transactions are available:
#Component
public class YourService
implements ApplicationListener<ContextRefreshedEvent> // <= ensure correct timing!
{
private final YourRepo repo;
public YourService (YourRepo repo) {this.repo = repo;}
#Transactional // <= ensure transaction!
#Override
public void onApplicationEvent(ContextRefreshedEvent event) {
repo.doSomethingWithinTransaction();
}
}
Using transactionOperations.execute() in #PostConstruct or in #NoTransaction method both works
#Service
public class ConfigurationService implements ApplicationContextAware {
private static final Logger LOG = LoggerFactory.getLogger(ConfigurationService.class);
private ConfigDAO dao;
private TransactionOperations transactionOperations;
#Autowired
public void setTransactionOperations(TransactionOperations transactionOperations) {
this.transactionOperations = transactionOperations;
}
#Autowired
public void setConfigurationDAO(ConfigDAO dao) {
this.dao = dao;
}
#PostConstruct
public void postConstruct() {
try { transactionOperations.execute(new TransactionCallbackWithoutResult() {
#Override
protected void doInTransactionWithoutResult(final TransactionStatus status) {
ResultSet<Config> configs = dao.queryAll();
}
});
}
catch (Exception ex)
{
LOG.trace(ex.getMessage(), ex);
}
}
#NoTransaction
public void saveConfiguration(final Configuration configuration, final boolean applicationSpecific) {
String name = configuration.getName();
Configuration original = transactionOperations.execute((TransactionCallback<Configuration>) status ->
getConfiguration(configuration.getName(), applicationSpecific, null));
}
#Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
}
}
Is it by any means possible to #Inject a Service-Bean (say a session bean) into an entity Listener?
Consider the following scenario as an example
Entity:
#Entity
#EntityListeners(BookListener.class)
public class Book {
// fields, getters & setters
}
Utility class:
#Singleton
public class BookUtil {
private BookRepository bookRepo;
private List<Book> bookList;
#Inject
public BookUtil(BookRepository bookRepo){
this.bookRepo = bookRepo;
this.bookList = this.bookRepo.findAll();
}
public void refreshBooks(){
this.bookList = this.bookRepo.findAll();
}
}
Listener:
public class BookListener {
#Inject
BookUtil bookUtil // --> CAN THIS BE ACHIEVED?
#PostPersist
private void refreshCache(Book b){
bookUtil.refreshBooks();
}
}
I tried out several things I could think of but none of them successfully injected an instance of BookUtil. I could manually instantiate it, which works. But I prefer injection as then the BookRepository(inside the BookUtil) would also be injected, without me having to worry about it
I read a lot about the possibility of injection with jax rs 2.0 and in particular with jersey.
I even read that ejb injection is expected in jax rs 2.0 spec. But i still haven't found a unique solution among the variety of posts i read over the net.
In my use case i'm working with:
WildFly 9.0 and Jersey 2.x
I have a webapplication exposing my REST services and importing a jar implementing my model data.
This is the CDI approach:
#RequestScoped
#Path("/myPath")
public class ModelRetriever {
#Context
SecurityContext securityContext;
#Inject
private IMyModel MyModel;
#Path("{i}")
#GET
#Produces("application/json")
public Response countries(#PathParam("i") String countryId)
throws JSONException, Failure, IOException {
MyModel.doSomething();
}
This is my IMyModel interface
public interface IKasPrincipal extends Principal {
public void doSomething();
}
And this is MyModel implementation:
#RequestScope
public class MyModelImpl implements IMyModel {
public void doSomehting() {
doSomething();
}
}
Another method i tried is to use EJB injection changing my previous annotations like this:
#Stateless
#Path("/myPath")
public class ModelRetriever {
#EJB
private IMyModel MyModel;
#Path("{i}")
#GET
#Produces("application/json")
public Response countries(#PathParam("i") String countryId)
throws JSONException, Failure, IOException {
MyModel.doSomething();
}
This is my IMyModel interface
#Local
public interface IKasPrincipal extends Principal {
public void doSomething();
}
And this is MyModel implementation:
#Stateless
public class MyModelImpl implements IMyModel {
public void doSomehting() {
doSomething();
}
}
i get a null object using EJB approach and i get this exception using CDI
Caused by: org.glassfish.hk2.api.UnsatisfiedDependencyException: There was no object available for injection at SystemInjecteeImpl(requiredType=IMyModel,parent=ModelRetriever,qualifiers={},position=-1,optional=false,self=false,unqualified=null,616459318)
at org.jvnet.hk2.internal.ThreeThirtyResolver.resolve(ThreeThirtyResolver.java:75)
at org.jvnet.hk2.internal.ClazzCreator.resolve(ClazzCreator.java:211)
at org.jvnet.hk2.internal.ClazzCreator.resolveAllDependencies(ClazzCreator.java:234)
So is there anything i'm missing?
see other Stack Overflow related posts:
Dependency injection with Jersey 2.0
HK2 Jersey EJB 3 injection
The problem you are having is that HK2 does not know about anything that was not registered directly into it, and HK2 tries to to satisfy all dependency in your Jersey aware class.
I has this issue a while back. Then I discovered that Jersey uses HK2 internally. HK2 is a JSR-330 implementation (CDI).
One would think that a open-source project would declares it's CDI beans and use them regardless of the CDI implementation, but it looks like its not that way.
see : https://java.net/jira/browse/JERSEY-1933
see : https://hk2.java.net/integration.html
You can register your components into HK2...
see : https://jersey.java.net/documentation/latest/ioc.html
For all I know, you cannot inject CDI components (or anything else, as EJB) into Jersey's classes using your own (or your container's) CDI implementation, unless you use Glassfish (which personally I would never use) which in turn uses HK2 as its CDI implementation.
To me, this is a major draw back. But the only(?) draw back of Jersey.
-Maybe I missed something (which is very possible)
-Maybe this is a trick from Oracle so that you can't use Jersey in, let's say, your Websphere app which uses OpenWeb Beans as CDI implementation.
-Maybe they hardwired it to HK2, and just don't care that Jersey can't be used as a drop in component in your application, which relies on CDI or EJB
I'm not aware of why #EJB not worked, but, you can use #Produces/#Disposes bean.
#ApplicationScoped // or some other scoped
public class MyModelProducer {
#Produces public MyModel produceMyModel() {
}
public void disposeMyModel#Disposes final MyModel model) {
}
}
I have a simple AttributeConverter implementation in which I try to inject an object which have to provide the conversion logic, but #Inject seem not to work for this case. The converter class looks like this:
#Converter(autoApply=false)
public class String2ByteArrayConverter implements AttributeConverter<String, byte[]>
{
#Inject
private Crypto crypto;
#Override
public byte[] convertToDatabaseColumn(String usrReadable)
{
return crypto.pg_encrypt(usrReadable);
}
#Override
public String convertToEntityAttribute(byte[] dbType)
{
return crypto.pg_decrypt(dbType);
}
}
When the #Converter is triggered it throws an NullPointerException because the property crypto is not being initialized from the container. Why is that?
I'm using Glassfish 4 and in all other cases #Inject works just fine.
Is it not possible to use CDI on converters?
Any help will be appreciated :)
The accent of my question is more the AttributeConverter part. I understand that for the CDI to work a bean must meet the conditions described here http://docs.oracle.com/javaee/6/tutorial/doc/gjfzi.html.
I also have tried to force the CDI to work by implementing the following constructor:
#Inject
public String2ByteArrayConverter(Crypto crypto)
{
this.crypto = crypto;
}
And now I got the following exception which doesn't give me any clue:
2015-07-23T01:03:24.835+0200|Severe: Exception during life cycle processing
org.glassfish.deployment.common.DeploymentException: Exception [EclipseLink-28019] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.EntityManagerSetupException
Exception Description: Deployment of PersistenceUnit [PU_VMA] failed. Close all factories for this PersistenceUnit.
Internal Exception: Exception [EclipseLink-7172] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.ValidationException
Exception Description: Error encountered when instantiating the class [class model.converter.String2ByteArrayConverter].
Internal Exception: java.lang.InstantiationException: model.converter.String2ByteArrayConverter
at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.createDeployFailedPersistenceException(EntityManagerSetupImpl.java:820)
at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:760)
...
I even tried using #Producer or #Decorator in order to have the CDI working on that place, but I still think there is something specific with the AttributeConverter which doesn't allow CDI. So problem not solved yet.
Unfortunately you can't inject CDI beans into a JPA converter, however in CDI 1.1 you can inject your Crypto programmatically :
Crypto crypto = javax.enterprise.inject.spi.CDI.current().select(Crypto.class).get()
For reference, JPA 2.2 will allow CDI to be used with AttributeConverter, and some vendors already support this (EclipseLink, DataNucleus JPA are the ones I know of that do it).
You're trying to combine two different worlds, as CDI doesn't know about JPA Stuff and vice-versa. (One annotation parser of course doesn't know about the other)
What you CAN do, is this:
/**
* #author Jakob Galbavy <code>jg#chex.at</code>
*/
#Converter
#Singleton
#Startup
public class UserConverter implements AttributeConverter<User, Long> {
#Inject
private UserRepository userRepository;
private static UserRepository staticUserRepository;
#PostConstruct
public void init() {
staticUserRepository = this.userRepository;
}
#Override
public Long convertToDatabaseColumn(User attribute) {
if (null == attribute) {
return null;
}
return attribute.getId();
}
#Override
public User convertToEntityAttribute(Long dbData) {
if (null == dbData) {
return null;
}
return staticUserRepository.findById(dbData);
}
}
This way, you would create a Singleton EJB, that is created on boot of the container, setting the static class attribute in the PostConstruct phase. You then just use the static Repository instead of the injected field (which will still be NULL, when used as a JPA Converter).
Well, CDI still doesn't work for AttributeConverter, which would be the most elegant solution, but I have found a satisfying workaround. The workaround is using #FacesConverter. Unfortunately per default CDI doesn't work in faces converters and validators either, but thanks to the Apache MyFaces CODI API you can make it work unsing the #Advaced annotation :) So I came up with an implementation like this:
#Advanced
#FacesConverter("cryptoConverter")
public class CryptoJSFConverter implements Converter
{
private CryptoController crypto = new CryptoController();
#Inject
PatientController ptCtrl;
public Object getAsObject(FacesContext fc, UIComponent uic, String value)
{
if(value != null)
return crypto.pg_encrypt(value, ptCtrl.getSecretKey());
else
return null;
}
public String getAsString(FacesContext fc, UIComponent uic, Object object)
{
String res = crypto.pg_decrypt((byte[]) object, ptCtrl.getSecretKey());
return res;
}
}
The injected managed bean has to be explicitly annotated with #Named and some scope definition. A declaration in faces-config.xml doesn't work! In my solution it looks like this:
#Named
#SessionScoped
public class PatientController extends PersistanceManager
{
...
}
Now one has a context information in the converter. In my case it is session/user specific cryptography configuration.
Of course in such a solution it is very likely that a custom #FacesValidator is also needed, but thanks to CODI one have the possibility for using CDI here also (analog to converter).
I am developing e4 application. I want to inject EPartService outside the Part and Handler
when i am injecting EPartService then i will get null pointer error
public class DisplayRuntimePart {
#Inject EPartService partService;
private void displayPart(){
MPart part=partService.findPart("com.rcpe4.myproject.part.datapart");
mpart.setVisible(true);
partService.showPart(mpart, PartState.CREATE);
}
}
I am also read this question but till not solve my problem E4 EPartService findPart() throwing java.lang.Null Pointer Exception
Edit
I am inject EPartService in Part class. Class URI in Application.e4xml is bundleclass://com.abc.test/com.abc.test.part.MyPart in this class I am write code as follows.
Class Mypart{
#Inject EPartService prtservice;
#Inject
public MyPart() {
}
#PostConstruct
public void postConstruct(Composite parent) {
parent.setLayout(new FillLayout(SWT.HORIZONTAL));
htmlBrowser = new Browser(parent, SWT.NONE);
}
#PreDestroy
public void preDestroy() {
}
#Focus
public void onFocus() {
}
#Persist
public void save() {
}
public dispalyPart(){
MPart mpart=partService.findPart("com.abc.test.part.datapart"); **Here Getting Null Pointer Exception**
mpart.setVisible(true);
partService.showPart(mpart, PartState.CREATE);
}
}
Eclipse only does direct injection on objects that it 'knows' about - basically objects mentioned in the application model (e4xmi) files or created using something like EPartService.showPart.
If you want to do direct injection on objects that you create then you need to create them using ContextInjectionFactory. For example:
#Inject IEclipseContext context;
...
MyClass myClass = ContextInjectionFactory.make(MyClass.class, context);
you can also do injection on a class created in the normal way with:
ContextInjectionFactory.inject(myClass, context);
(this will not do injection on the constructor).
Note: Since this code is using direct injection you must run it from a class that the Eclipse application model does know about such as a command handler or an MPart.