jfreechart 的相关错误 addOrUpdate()

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)

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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。

1 楼 wl8685 2012-02-14 这是因为构造数据集合里的时间参数有问题。
timeSeries.add(new Year().parseYear("2012"),10000);即可