Best practice [referencing from entity to session beans]

[hipa]

I have some kind of runtime configuration in my application: entity may contain a reference to the name of some session bean.

public interface MyPolicy
{
 public String get();
}

@Stateless
@Local(MyPolicy.class)
public class MyPolicy1 implements MyPolicy
{
 public String get()
 {
 return "This is policy 1";
 }
}

@Stateless
@Local(MyPolicy.class)
public class MyPolicy2 implements MyPolicy
{
 public String get()
 {
 return "This is policy 2";
 }
}

@Entity
....
public class MyEntity
{
 private String policyClass;
 ...

 protected String getPolicyClass()
 {
 return policyClass;
 }

 protected void setPolicyClass(String policyClass)
 {
 this.policyClass = policyClass;
 }
}

Should I also add transient methods to these entities to get real session bean or use another session bean (or simple utility method) to retrieve bean at runtime?

public class MyEntity
{
 private String policyClass;
 private transient MyPolicy policy;
 ...

 protected String getPolicyClass()
 {
 return policyClass;
 }

 protected void setPolicyClass(String policyClass)
 {
 this.policyClass = policyClass;
 }

 @Transient
 public MyPolicy getPolicy()
 {
 if (policy == null)
 {
 try
 {
 policy = new InitialContext().lookup(policyClass);
 }
 catch (NamingException e)
 {
 throw new IllegalStateException("Misconfiguration exception", e);
 }
 }

 return policy;
 }
}

Then is some session bean:

 ...
 log.debug(myEntity.getPolicy().get());

OR

 ...
 MyPolicy policy = Utils.lookup(myEntity.getPolicyClass());
 log.debug(policy.get());

It's convenient to have a set of methods of entity to get these beans but I don't want these methods to be visible on RMI clients (and also I have bad (or not so bad?) dependency of persistence layer from business-logic beans interfaces).