How to refactor managed bean

Question

Disclaimer: I am very new to ADF.
I have a fragment that uses a pageFlow scoped managed bean. Everything works fine but now I have to extract a piece of that fragment and use it into another fragment. I would like to extract all parts related to that fragment into a specific managed bean and then use that managed bean into the "parent" managed bean. To clarify what I want to do:
Current:
public class BigManagedBean {
private String classMemberSpecificToA;
private String classMemberSpecificToB;
Refactored:
public class BigManagedBean {
private SpecificToAManagedBean aBean;
private SpecificToBManagedBean bBean;
public SpecificToAManagedBean {
private String classMemberSpecificToA;
public SpecificToBManagedBean {
private String classMemberSpecificToB;
Q: How to instantiate aBean and bBean? What is the best practice for doing that?
ADF 11.1.1.6

Answer 1

Three ways:
1) instantiate the variable with the bean
public class BigManagedBean {
private SpecificToAManagedBean aBean = new SpecificToAManagedBean ();
private SpecificToBManagedBean bBean = new SpecificToBManagedBean ();
2) in the constructor of the big bean
public class BigManagedBean {
private SpecificToAManagedBean aBean;
private SpecificToBManagedBean bBean;
  public BigManagedBean()
    aBean = new SpecificToAManagedBean ();
    bBean = new SpecificToBManagedBean ();
3) in the getter of aBean
public class BigManagedBean {
private SpecificToAManagedBean aBean = null;
private SpecificToBManagedBean bBean = null;
  public SpecificToAManagedBean getABean()
    if (aBean == null)
         aBean = new SpecificToAManagedBean ();
    return aBean;
Timo