JFreeChart 是一个开源项目，它的功能非常强大，可以实现饼图( 二维和三维 )、柱状图( 水平、垂直 )、 线图、点图、时序图等常用商用图表，图形可以导出成 PNG 和 JPEG 格式，同时还可以与 PDF 和 EXCEL 关联，支持对图形的放大、缩小，支持常见图形的 3D 显示。本文对JFreeChart的应用、类架构和设计模式进行了详细分析。-JFreeChart is an open source project, it is very powerful, can achieve pie (two and three dimensions), histogram (horizontal, vertical), line graph, diagram, sequence diagram and other common business charts, graphs can be exported as PNG and JPEG format, but also can be associated with the PDF and EXCEL, to support graphics zoom, support for common 3D graphics display. In this paper, the application of JFreeChart, class architecture and design patterns are analyzed in detail.