I am new to EJB3.1 .Please bear with me if this is a trivial question. My requirement is to have a singleton class which will have certain data shared across different beans. And to have different Threads accessing this singleton class's data . Let me try to explain using two different class called A and B .
@Singleton
//@Local?? ,@Remote?? or @LocalBean ?
class A {
private List<CommonDTO> commonDTOList = new ArrayList<CommonDTO>();
.
. //other member variables, EJB beans which implement Remote interfaces.
.
init(){
//initialise commonDTOList here.
}
//getter
List<SomeDTO> getCommonDTOList(){
return commonDTOList;
}
}
@Stateless
Class B implements Interface { //Interface is @Remote
//need to access singleton Class A's getter , so that all the threads have the same commonDTOList.
@EJB
private A classA;
.
.//other member variables
.
@OverRide //overriding Interface2's method
public void doSomething(){
.
.//do some database transactions here , which can be done parallely by multiple threads, since this is stateless.
.
//now retrieve Class A'S CommonDTOList.
//This List should be shared across multiple threads of this stateless bean.
List<SomeDTO> someDTOListInsideStatelessBean = classA.getCommonDTOList();
}
}
Question is what annotation I should on ClassA so that I can access its List in another Stateless bean.?
I have tried the following but in vain.
1) @Local I cannot use because like mentioned in the inline comments above .In classA that member variables has @EJB beans which implement @Remote interfaces.
2) @LocalBean looks to be the one used here in this scenario. However , once inside the method "doSomething()" of ClassB, the classA variable has all its
member variable as null .Although the List was initialised during start up.
I was under the impression that since its singleton , there will be only instance shared
across all beans.
3)@Remote I am not sure if I should be using here , however no luck with that too.
please help. Thanks in advance.
