ilog.views.chart.servlet

Class IlvComponentSessionAttribute

java.lang.Object

ilog.views.chart.servlet.IlvComponentSessionAttribute

All Implemented Interfaces:

EventListener, javax.servlet.http.HttpSessionBindingListener

Direct Known Subclasses:

IlvChartSessionAttribute

public class IlvComponentSessionAttribute
extends Object
implements javax.servlet.http.HttpSessionBindingListener

The IlvComponentSessionAttribute class acts as a proxy for a GUI component bound to an HttpSession. When you bind a GUI component as an attribute of an HttpSession, proper cleanup of the component must occur when the session is invalidated or expires. This allows the component to be garbage collected or restored to a pool of available components, depending on your choice of strategies. Instead of binding the component directly to the session, use an instance of this class as a proxy:

 Component component = null;
 HttpSession session = request.getSession();
 if (session.isNew()) {
   component = ... create new or fetch from pool ...
   IlvComponentSessionAttribute proxy =
     new IlvComponentSessionAttribute(component);
   session.setAttribute(COMP_KEY, proxy);
 } else {
   IlvComponentSessionAttribute proxy =
     (IlvComponentSessionAttribute)session.getAttribute(COMP_KEY);
   if (proxy != null)
     component = proxy.getComponent();
 }
 if (component == null)
   throw new ServletException("session problem");
 

When all the sessions that the proxy and its component are associated with expire, the componentUnbound() method of the proxy will be invoked. You can override this method to customize your strategy for handling components that are no longer associated with any sessions.

Since:

JViews 5.5

Constructor Summary

Constructors

Constructor and Description
IlvComponentSessionAttribute(Component component) Creates an IlvComponentSessionAttribute proxy for the specified component.

Method Summary

Modifier and Type	Method and Description
protected void	componentUnbound() This method is automatically invoked when the proxy is unbound from its last HTTP session.
Component	getComponent() Returns the proxy component.
void	valueBound(javax.servlet.http.HttpSessionBindingEvent event) This method is automatically invoked when the proxy is bound to an HTTP session.
void	valueUnbound(javax.servlet.http.HttpSessionBindingEvent event) This method is automatically invoked when the proxy is unbound from an HTTP session.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

IlvComponentSessionAttribute

public IlvComponentSessionAttribute(Component component)

Creates an IlvComponentSessionAttribute proxy for the specified component.

Parameters:

component - The component.

Method Detail

getComponent

public Component getComponent()

Returns the proxy component.

Returns:

The component.

componentUnbound

protected void componentUnbound()

This method is automatically invoked when the proxy is unbound from its last HTTP session. This method is invoked on the Swing event queue, making it safe to change the attributes of the proxy GUI component. This default implementation removes the component from any top-level Window it may have been added to, and disposes the window. Subclasses can override this method to provide specialized cleanup of the proxy component.

valueBound

public void valueBound(javax.servlet.http.HttpSessionBindingEvent event)

This method is automatically invoked when the proxy is bound to an HTTP session.

Warning: This method is considered to be part of an IlvComponentSessionAttribute's internal implementation and is not a public API.

Specified by:

valueBound in interface javax.servlet.http.HttpSessionBindingListener

valueUnbound

public void valueUnbound(javax.servlet.http.HttpSessionBindingEvent event)

This method is automatically invoked when the proxy is unbound from an HTTP session. Subclasses should not override this method to provide a special cleanup strategy for the proxy component. Override the componentUnbound() method instead.

Warning: This method is considered to be part of an IlvComponentSessionAttribute's internal implementation and is not a public API.

Specified by:

valueUnbound in interface javax.servlet.http.HttpSessionBindingListener