代码如下:
DefaultPieDataset piedata = new DefaultPieDataset();
//第一个参数为名称,第二个参数是double数
piedata.setValue("空座", tj1);
piedata.setValue("预定", tj3);
piedata.setValue("已售", tj2);
//创建JFreeChart,都使用ChartFactory来创建JFreeChart,很标准的工厂设计模式
JFreeChart chart = ChartFactory.createPieChart(title, piedata, true, true, true);
chart.setBackgroundPaint(Color.white);
String filename = ServletUtilities.saveChartAsPNG(chart, 650, 350, null, session);
FileOutputStream fos_jpg = null;
String graphURL = new java.io.File(request.getRealPath(request.getServletPath())).getParent() + "/upload/" + filename;
try {
fos_jpg=new FileOutputStream(graphURL);
ChartUtilities.writeChartAsJPEG(fos_jpg,1.0f,chart,640,480,null);
fos_jpg.close();
} catch (Exception e) {
e.printStackTrace();
}
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