Event handlers can be attached to individual plots of a chart, as shown in Listing 6.
事件处理程序可以附加到一个图表的单独绘图区，如清单6所示。
2
In the scenario above it seems that there is a periodic event happening every 20 minutes that cause a spike in the load average chart.
在上面的情形中，好像有周期性的事件每20分钟发生一次，从平均负载图上显示的波峰可以看到这一点。
3
Let's take a close look at the implementation of the chart data updater and how to publish a server event to clients with the JMS topic connection factory.