ejb-3.0

问题 Our code has something like this: @Resource(name = "java:comp/resource/foo/bar/ONE_QUEUE") private Queue queue; However, in one deployment scenario the queue annotation should look like this: @Resource(name = "java:comp/resource/foo/bar/SECOND_QUEUE") private Queue queue; I would like to choose the name to use with Maven build profiles. What options do I have? 回答1: This is not the right way to do things. Resources should be added to the local jndi name of individual EJBs. This is to separate

问题 I have understood that if I use EJB in Spring context, I get all the same benefits as if I was using it in "pure" EJB3 environment, is this true? I have googled but can't find a definitive, clear answer. For example, let's say I have a session bean that updates some tables in the database and it throws a System Exception. In "pure" EJB3 environment the transaction is rolled back. What if I for example @Autowire this bean using Spring, does Spring take care of the transaction handling same way

问题 Now, with EJB 3.1, we can find the javax.ejb.Singleton annocation that can ensure that this bean is going to be singleton. Is there a way that i can ensure singleton using stateless beans in EJB 3.0 with some modifications in my code (use of the keyword static, or other way to do that....) 回答1: If you're able to limit your @Stateless bean pool size to exactly 1, then you can get pretty close to an @Singleton . The effect would be like having an @Singleton that uses @Lock(WRITE) for all calls

问题 I am trying to invoke a EJB from a standalone Java client, getting the below error. Lookup code String localJNDIName = "ejbremote:gcmsnew/gcmsutilbeans.jar/CustomerSurveyManageQstBean#com.smbcgroup.gcms.utility.bl.survey.CustomerSurveyManageQstRemote"; InitialContext ic = new InitialContext(); GCMSBaseRemote bean = (GCMSBaseRemote)ic.lookup(localJNDIName); Exception javax.naming.ConfigurationException: NamingManager.getURLContext cannot find the factory for this scheme: ejbremote at com.ibm

问题 I am using a JEE6 stack including JPA 2.0, JSF 2.0, EJB 3.1 etc. The way my architecture is setup is the following: I have JPA annotated DAOs using hibernate as my JPA provider. I have JSF Managed beans which correspond to my facelet/xhtml pages. I have EJBs that handle all of my database requests. My XHTML pages have JSF EL which make calls to my Managed beans. My managed beans contain references to my DAO entities which are managed by EJBs. For example, I have a user entity which is mapped

问题 I've written an authorization system which relies on objects representing the current user. To simplify programming and increase performance I want to hold those objects in a ThreadLocal after the user has logged in. It looks like this: public class UserCache { private static final ThreadLocal<User> cache = new ThreadLocal<User>(); public User getCurrentUser() { return cache.get(); } public void setCurrentUser(User user) { cache.set(user); } } I've read that static elements make clustering

问题 In a CMT J2EE environement (Container Managed Transaction) what transaction / connection is used when I JDNI-lookup for a DataSource object and invoke DataSource.getConnection ? Is this connection part of the (potentially distributed) transaction? Does getConnection() return the same Connection every time I call it for the same DataSource object? I only know using Connections by the same EntityManager using native SQL statements. It is something that keeps me puzzling. As I understood the

问题 I am adding two JMS messages in the same destination sequentially. Will both of these messages be received in the same order in which I have added them or is there a chance for reverse ordering, that is, which ever the message is received first in the destination will be retrieved first. I am adding into a destination as: producer.send(Msg1); producer.send(Msg2); Msg1 and Msg2 will be added sequentially in all the cases (like network failures and latency. etc.)? 回答1: Message ordering is not

问题 In Weblogic 10.3, how do I inject a remote EJB from one EAR into a Stateless bean of another, both EARs being deployed in the same container? Ideally I'd like to do as much as possible with annotations. So suppose I have the following interface: public interface HelloService { public String hello(); } implemented by the following EJB: @Stateless @Remote public class HelloServiceBean implements HelloService { public String hello() { return "hello"; } } Suppose they're packaged and deployed in

问题 There are so many things are common in in EJB3 and Spring 3 with hibernate. I need to findout where I can use Spring framework with hibernate not EJB3 and viceversa. 回答1: You can use them interchangeably. If you go with EJB3, you'll have to have a full Java EE, EJB3 app server. Some are free, some are not. If you go with Spring 3, you need to have the Spring JARs in your CLASSPATH, but a full Java EE app server is not required. Tomcat or Jetty are sufficient, depending on your needs. There