一个自己编写的应用jfreechart生成piechart的类。注意在调用genPicture()之前首先要设置title,data,remoteAddr的值。genPicture()返回生成的图片的路径，可在前台页面中调用此图片显示chart。-an own applications written jfreechart generation piechart class. Calling attention to the genPicture () to be installed befor