ejb-3.1

问题 Stateles ejbs are intended to be idempotent and have no memory of previous user interactions. That sounds like a static method to me. so instead of having public void save(Entity e) { em.persist(e); } is it safe to have public static void save(Entity e) { em.persist(e); } inside an EJB? 回答1: No, because static methods do not participate in container-managed transactions, AOP, security, etc. BTW your second example won't compile, em is injected by the application server and it can't be static

问题 Inside a BMT (using a UserTransaction ) I call a method on another stateless EJB. When I rollback this transaction, the entity created in the EJB method is not rolled back. I use EJB 3.1 with JPA 2.0. The transaction begins in method doTheTransaction() : @Stateless @LocalBean @TransactionManagement(TransactionManagementType.BEAN) public class TaskExecutor { @Inject private SomeEntityFacade someEntityEJB; @Inject private RandomEJB randomEJB; @Resource private UserTransaction ut; @Asynchronous

问题 i am working on an application(enterprize application in java) in which i need is single instance to be shared by multiple thread concurrently for which i have used @singleton . when each user login a value is set in telecallers List by invoking setTeleCallersDetails() remote method. but at certain point when number of user logged in exceed 15 then @singleton starts behaving like @stateless bean as setTeleCallersDetails() start adding value in new tellcaller arraylist. can anybody tell to

问题 I'm trying to get the percentage of the progress from a EJB Asynchronous process. Is this possible? Does anyone have an idea how I could do this? 回答1: To get to know the progress of asynchronous processes is always tricky, especially if you don't know if they have actually started yet. The best way I have found is to write another function that just gets the progress, so, if you have some unique id for each call, then update a hashmap with the current process. You may want to look at

问题 I read a lot on this topic on SO and the web but there seem to be problems when dealing with older posts... I want to expose my EJB business logic to a rest api / inject an ejb into a jersey resource. Using @EJB works fine but there are people out there suggesting not to use @EJB for local beans. There are different methods to inject beans in services with @Inject. The easiest (to me) seems to be the following: @RequestScoped // This line is important! @Path("service") public class Rest {

问题 I have a EAR package that contains a web module and EJB. The EJB is currently exposed its contains to local app client via Remote interface @Stateless public class CoreEJB implements CoreEJBRemote { @PersistenceContext(unitName = "CoreWeb-ejbPU") private EntityManager em; @Override public void packageProcess(String configFileName) throws Exception { //Process logics } @Override public <T> T create(T t) { em.persist(t); return t; } @Override public <T> T find(Class<T> type, Object id) { return

问题 There is lot of information about Stateless, Stateful and Sigleton beans everywhere but almost nothing about javax.annotation.ManagedBean . At a first look I assumed that It's be similar to Spring's @Component but I can't use it without complete information. If I annotate a class with @javax.annotation.ManagedBean will it be singleton or it will have instance pool like stateless? Will the methods inside such class be concurrent? I should make sure as in a singleton they are synchronized by

问题 I created a EJB3.1 and injected CDI bean using the @inject but facing some issues while unit testing however when tested from the servlet its working fine. I have the beans.xml in the WEB-INF folder. Below is my EJB code: @Stateless public class CdiUsingEjb { @Inject private HelloServletCDIPojo helloServletCDIPojo; public String greet() { assert helloServletCDIPojo != null; return helloServletCDIPojo.from(); } } Below is my CDI bean: public class HelloServletCDIPojo { public String from() {

问题 I created a EJB3.1 and injected CDI bean using the @inject but facing some issues while unit testing however when tested from the servlet its working fine. I have the beans.xml in the WEB-INF folder. Below is my EJB code: @Stateless public class CdiUsingEjb { @Inject private HelloServletCDIPojo helloServletCDIPojo; public String greet() { assert helloServletCDIPojo != null; return helloServletCDIPojo.from(); } } Below is my CDI bean: public class HelloServletCDIPojo { public String from() {

问题 I'm having difficulty with my EJB3.1 bean initialisation and more specifically to do with it failing due to perceived transaction rollback, even though I've marked the bean with @TransactionAttribute(NOT_SUPPORTED) . This should mean that any client transaction is paused on bean method entry until exit (when it will be resumed. It's definitely the transactional apprach I want. The "gist" of the code and error are as follows (note some of it is hand-cranked to hide details but is all relevant