java.lang.Object | +--java.beans.beancontext.BeanContextChild
java.beans.beancontext.BeanContext
void | addPropertyChangeListener(java.lang.String prop, java.beans.PropertyChangeListener listener) Add a listener that will be notified when a specific property changes. |
void | addVetoableChangeListener(java.lang.String prop, java.beans.VetoableChangeListener listener) Add a listener that will be notified when a specific property change is requested (a PropertyVetoException may be thrown) as well as after the change is successfully made. |
java.beans.beancontext.BeanContext | getBeanContext() Get the parent |
void | removePropertyChangeListener(java.lang.String prop, java.beans.PropertyChangeListener listener) Remove a listener to a certain property. |
void | removeVetoableChangeListener(java.lang.String prop, java.beans.VetoableChangeListener listener) Remove a listener to a certain property. |
void | setBeanContext(java.beans.beancontext.BeanContext parent) Set the parent |
public void addPropertyChangeListener(java.lang.String prop, java.beans.PropertyChangeListener listener)
prop
- the name of the property to listen onlistener
- the listener to listen on the property.public void addVetoableChangeListener(java.lang.String prop, java.beans.VetoableChangeListener listener)
prop
- the name of the property to listen onlistener
- the listener to listen on the property.public BeanContext getBeanContext()
BeanContext
.
BeanContext
.public void removePropertyChangeListener(java.lang.String prop, java.beans.PropertyChangeListener listener)
prop
- the name of the property being listened onlistener
- the listener listening on the property.public void removeVetoableChangeListener(java.lang.String prop, java.beans.VetoableChangeListener listener)
prop
- the name of the property being listened onlistener
- the listener listening on the property.public void setBeanContext(java.beans.beancontext.BeanContext parent)
BeanContext
.
This method is called from BeanContext.add()
and
should not be called directly.
When this Object is being added to a new BeanContext or moved from an old one, a non-null value will be passed in.
When this Object is being removed from the current
BeanContext
, setBeanContext()
will
receive the parameter null
.
When being removed from the current BeanContext
,
it is the BeanContextChild
's responsibility to
release all services it has obtained.
This change should generate PropertyChangeEvent
and VetoableChangeEvent
s with the property name
"beanContext". If the change is vetoed, it must re-throw the
exception and not change anything. In this way, the parent
BeanContextChild
, who has registered himself with
you, will have a chance to remove this child from its
collection.
If the Bean does not wish to change the parent or be removed
from one, it may throw the PropertyVetoException
.
If you veto a setBeanContext(null)
call, then you
should try your hardest to remedy whatever problem is keeping
you from being removed from the BeanContext
so
that you can not veto it the next time.
Otherwise, nasty pathological recursion stuff could occur in
certain situations.
If you do veto the change, you must first back out any changes you made prior to the veto. Best not to make any such changes prior to the veto in the first place.
This method is called from BeanContext.add()
and
should not be called directly.
parent
- the new parent for the BeanContextChild
,
or null
to signify removal from a tree.PropertyVetoException
- if the
BeanContextChild
implementor does not
wish to have its parent changed.
The difference between a
BeanContext
and aBeanContextChild
, mainly, is that aBeanContext
may be a parent.BeanContextChild
instances will be serialized at some point in their life, but you need to make sure your bean context does not contain a serializable reference (directly or indirectly) to the parentBeanContext
, to any of the otherBeanContext
s in the tree, or to any resources obtained via theBeanContextServices
interface. One way to do this is to mark any fields that contain such references astransient
. Another way is to use a custom serializer.If you do not do this, when the
BeanContext
is serialized, all the otherBeanContext
s and other unnecessary things will be serialized along with it.Before dying, a
BeanContextChild
should callgetBeanContext().remove(this)
to detach from the hierarchy and exit cleanly.