jfreechart 的相关错误 addOrUpdate()

fish_bone

org.jfree.data.general.SeriesException: You are attempting to add an observation for the time period Wed Apr 06 11:49:00 CST 2011 but the series already contains an observation for that time period. Duplicates are not permitted.  Try using the addOrUpdate() method.
    at org.jfree.data.time.TimeSeries.add(TimeSeries.java:527)
    at org.jfree.data.time.TimeSeries.add(TimeSeries.java:570)
    at org.jfree.data.time.TimeSeries.add(TimeSeries.java:556)
    at com.my.jfreechart.Class.CreateXYAreaChartTools.getTimeSeriesMinute(CreateXYAreaChartTools.java:432)
    at com.my.jfreechart.Class.CreateXYAreaChartTools.getTimeSeries(CreateXYAreaChartTools.java:56)
    at com.my.jfreechart.Util.XYAreaChartPublicClass.getJFreeChart(XYAreaChartPublicClass.java:122)
    at com.alcornet.struts.action.ajax.AjaxAction.getJFreeChart(AjaxAction.java:280)
    at com.alcornet.struts.action.ajax.AjaxAction.execute(AjaxAction.java:84)
    at com.alcornet.struts.action.ajax.AjaxAction$$FastClassByCGLIB$$c73c8c38.invoke(<generated>)
    at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:149)
 
 
不知道为什么一直报这个错，后来重启电脑，就不报这个错了，图就出来了。