jfreechart的一个小问题

今天在写实时曲线图时报了这样一个错！在网上找了找发现中文的很少！特此写下来与大家共享！
03:07:35 ERROR org.apache.jsp.html.portal.status_jsp._jspService(status_jsp.java:996) : org.jfree.data.general.SeriesException: You are trying to add data where the time period class is org.jfree.data.time.Year, but the TimeSeries is expecting an instance of org.jfree.data.time.Day.
org.jfree.data.general.SeriesException: You are trying to add data where the time period class is org.jfree.data.time.Year, but the TimeSeries is expecting an instance of org.jfree.data.time.Day.

报错时的代码：
TimeSeries timeseries = new TimeSeries("平均",Day.class);

timeseries.add(new Year( 2010), 12);


很明显是我把上下两个地方写的不一致所致的！呵呵！一时疏忽！


现改正如下：

TimeSeries timeseries = new TimeSeries("平均",Year.class);

timeseries.add(new Year( 2010), 102);

另外提醒别把报到错了哦！
应该是 org.jfree.data.time.*;哦

有不足之处望大家指点！！