You are experiencing the classic XA 2-PC race condition. It does happen in production environments. There are 3 things coming to my mind. Last agent optimization where JDBC is the non-XA resource.(Lose recovery semantics) Have JMS Time-To-Deliver. (Deliberately Lose real time) Build retries into JDBC code. (Least effect on functionality) Weblogic has this LLR optimization … Read more
RequiresNew does not create a nested transaction because the first transaction is suspended while the second transaction is running. A nested transaction looks like this: Nested transaction example > method1 – begin tran1 > method2 – begin tran2 workA < method2 – commit tran2 < method1 – rollback tran1 (tran2 also rolled back because it’s … Read more
There is no API to retrieve session by id. What you can do, however, is implement a session listener in your web application and manually maintain a map of sessions keyed by id (session id is retrievable via session.getId()). You will then be able to retrieve any session you want (as opposed to tricking container … Read more
You definitely shouldn’t create User_Group entity as it’s more the underlying database representation than the object oriented one. You can achieve the join table by defining something like: @Entity @Table(name=”USERS”, schema=”ADMIN”) public class User implements Serializable { //… @ManyToOne @JoinTable(name=”USER_GROUP”) Group group; @Entity @Table(name=”GROUPS”, schema=”ADMIN”) public class Group implements Serializable { //… @OneToMany(mappedBy=”group”) Set<User> users; … Read more
You can do something like @NamedQuery(name=”findWhatever”, query=”SELECT new path.to.dto.MyDto(e.id, e.otherProperty) FROM Student e WHERE e.id = ?1″) Then the MyDto object would just need a constructor defined with the correct fields i.e. public MyDto(String id, String otherProperty) { this.id = id; this.otherProperty = otherProperty; }
You do realize that the URL client sees (and/or types into his browser) and the URL served by the container your servlet is deployed on can be very different? In order to get the latter, though, you have a few methods available on HttpServletRequest: You can either call getScheme(), getServerName(), getServerPort() and getContextPath() and combine … Read more
You can find an answer here. I can suggest using org.reflections You can take a look at it here Reflections reflections = new Reflections(“com.mycompany”); Set<Class<? extends MyInterface>> classes = reflections.getSubTypesOf(MyInterface.class);
The difference between the two tags is that the way they work. Well, I will say an example so that you can imagine it better. Assume you have two pages, pageA, and pageB. In pageA you wrote the include tag. In this case the control was in pageA til you called the include tag. At … Read more
IN tests is value of single valued path expression (persistent attribute of your entity) in values you provided to query (or fetched via subquery). MEMBER OF tests is value you provided to query (or defined with expression) member of values in some collection in your entity. Lets’s use following example entity: @Entity public class EntityA … Read more
Omit the <auth-constraint> element in <security-constraint> for resources for which you don’t need authentication like: <security-constraint> <web-resource-collection> <web-resource-name>app</web-resource-name> <url-pattern>/info</url-pattern> </web-resource-collection> <!– OMIT auth-constraint –> </security-constraint> <security-constraint> <web-resource-collection> <web-resource-name>app</web-resource-name> <url-pattern>/*</url-pattern> </web-resource-collection> <auth-constraint> <role-name>Role</role-name> </auth-constraint> </security-constraint>