public class IlvChartSessionAttribute extends IlvComponentSessionAttribute
IlvChartSessionAttribute
class acts as a proxy for an
IlvChart
bound to an HttpSession
. When you bind
a chart as an attribute of an HttpSession
,
proper cleanup of the chart must occur when the session is invalidated or
expires. This allows the chart to be garbage collected or restored to a pool of available
charts, depending on your choice of strategies. Instead of binding the
chart directly to the session, use an instance of this class as a proxy:
When all the sessions that the proxy and its component are associated with expire, theIlvChart chart = null; HttpSession session = request.getSession(); if (session.isNew()) { chart = ... create new chart or fetch from pool ... IlvChartSessionAttribute proxy = new IlvChartSessionAttribute(chart); session.setAttribute(CHART_KEY, proxy); } else { IlvChartSessionAttribute proxy = (IlvChartSessionAttribute)session.getAttribute(CHART_KEY); if (proxy != null) chart = proxy.getChart(); } if (chart == null) throw new ServletException("session problem");
componentUnbound()
method of the proxy will be invoked.
You can override this method to customize your strategy for handling charts
that are no longer associated with any sessions.Constructor and Description |
---|
IlvChartSessionAttribute(IlvChart chart)
Creates an
IlvChartSessionAttribute proxy for the
specified chart. |
Modifier and Type | Method and Description |
---|---|
protected void |
componentUnbound()
This method is automatically invoked when the proxy is unbound from its
last HTTP session.
|
IlvChart |
getChart()
Returns the proxy chart.
|
getComponent, valueBound, valueUnbound
public IlvChartSessionAttribute(IlvChart chart)
IlvChartSessionAttribute
proxy for the
specified chart.chart
- The chart.public IlvChart getChart()
protected void componentUnbound()
componentUnbound
in class IlvComponentSessionAttribute
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