运行jfreechart Demo
1、http://www.jfree.org/jfreechart/index.html下载：jfreechart
2、解压缩：jar -xvf jfreechart-0.9.20.zip
3、运行jfreechart demo : java -jar jfreechart-demo.jar
或者：java -classpath lib/jcommon-0.9.5.jar:jfreechart-0.9.20.jar:jfreechart-0.9.20-demo.jar org.jfree.chart.demo.JFreeChartDemo
