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 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.
I have following simple page:
public class Login extends BasePage {
private UserDao userDao;
#Inject
public void setUserDao(UserDao userDao) {
System.out.println("setUserDao");
this.userDao = userDao;
}
Guice initialized with following code in Application:
#Override
protected void init() {
Module myBatisModule = new XMLMyBatisModule() {
#Override
protected void initialize() {
}
};
IbdGuiceModule ibdGuiceModule = new IbdGuiceModule();
getComponentInstantiationListeners().add(new GuiceComponentInjector(this, myBatisModule, ibdGuiceModule));
}
Setter injection doesn't work. setUserDao method is never called and userDao is null.
If I move #Inject annotation to the field, this works (setUserDao still not called but field value is initialized).
How to use setter injection?
Wicket supports only field injection.
Search in Google "Method injection considered harmful" for details.
In my GWTP application I need to Inject HttpServletRequest, HttpSession as instance variable of ActionHandler.
My ActionHandler is initialized through Spring.
I can't get current Request object through Spring as it instantiates just POJO.
I am thinking about mixing GIN and Spring.
Would I be able inject HttpServletRequest using GIN in my ActionHandler which is instantiated through Spring?????
Is it possible to do following way??
#Configuration
#Import(DefaultModule.class)
public class ServerModule extends HandlerModule
{
#Bean
public UserVerficationActionHandler getUserVerificationActionActionHandler()
{
return new UserVerficationActionHandler();
}
}
public class UserVerficationActionHandler implements ActionHandler<UserVerficationAction, UserVerficationActionResult>
{
#Autowired
private UserService userService;
private Provider<HttpServletRequest> requestProvider;
#Inject
public UserVerficationActionHandler()
{
}
public UserVerficationActionResult execute(UserVerficationAction action, ExecutionContext context) throws ActionException
{
....
}
#Inject
public Provider<HttpServletRequest> setRequestProvider()
{
return requestProvider;
}
}
-------ActionHandler Ends--------
Can somebody let me know Is it possible to do SetterInjection this way?
Second thing, if above is possible then will I be getting current request object using this method?
Thanks in advance.
Bhavesh.