xyitem.setBasePositiveItemLabelPosition(new ItemLabelPosition(ItemLabelAnchor.OUTSIDE12, TextAnchor.BASELINE_LEFT));
xyitem.setBaseItemLabelGenerator(new StandardXYItemLabelGenerator());
xyitem.setBaseItemLabelFont(new Font("Dialog", 1, 14));
plot.setRenderer(xyitem);
并引入了一些另外的包,引入包的语句变成:
<%@ page import = "org.jfree.chart.ChartFactory,
org.jfree.chart.title.TextTitle,
org.jfree.data.time.TimeSeries,
org.jfree.data.time.Month,
org.jfree.data.time.TimeSeriesCollection,
org.jfree.chart.plot.XYPlot,
org.jfree.chart.renderer.xy.XYLineAndShapeRenderer,
java.awt.Color,
org.jfree.ui.RectangleInsets,
java.awt.Font,
org.jfree.chart.renderer.xy.XYItemRenderer,
org.jfree.chart.JFreeChart,
org.jfree.chart.servlet.ServletUtilities,
org.jfree.chart.labels.*,
org.jfree.ui.*"%>
上面两例的曲线图都是但曲线的,有时候我们对两个曲线进行比较,例如对阿蜜果在2006年度和2007年度的blog访问量进行比较,在此种情况下,我们需要在一个曲线图中显示两个曲线。在此种情况下,我们只需要在sample1.jsp的基础上新建一个TimeSeries对象,给它添加数据后,将其添加到TimeSeriesCollection型数据集合对象中,修改后的程序主体部分如下所示:
//访问量统计时间线
TimeSeries timeSeries2006 = new TimeSeries("2006年度", Month.class);
TimeSeries timeSeries2007 = new TimeSeries("2007年度", Month.class);
//时间曲线数据集合
TimeSeriesCollection lineDataset = new TimeSeriesCollection();
//构造数据集合
timeSeries2006.add(new Month(1, 2007), 7200);
timeSeries2006.add(new Month(2, 2007), 7000);
timeSeries2006.add(new Month(3, 2007), 4200);
timeSeries2006.add(new Month(4, 2007), 8200);
timeSeries2006.add(new Month(5, 2007), 7300);
timeSeries2006.add(new Month(6, 2007), 8200);
timeSeries2006.add(new Month(7, 2007), 9200);
timeSeries2006.add(new Month(8, 2007), 7300);
timeSeries2006.add(new Month(9, 2007), 9400);
timeSeries2006.add(new Month(10, 2007), 7500);
timeSeries2006.add(new Month(11, 2007), 6600);
timeSeries2006.add(new Month(12, 2007), 3500);
timeSeries2007.add(new Month(1, 2007), 10200);
timeSeries2007.add(new Month(2, 2007), 9000);
timeSeries2007.add(new Month(3, 2007), 6200);
timeSeries2007.add(new Month(4, 2007), 8200);
timeSeries2007.add(new Month(5, 2007), 8200);
timeSeries2007.add(new Month(6, 2007), 11200);
timeSeries2007.add(new Month(7, 2007), 13200);
timeSeries2007.add(new Month(8, 2007), 8300);
timeSeries2007.add(new Month(9, 2007), 10400);
timeSeries2007.add(new Month(10, 2007), 12500);
timeSeries2007.add(new Month(11, 2007), 10600);
timeSeries2007.add(new Month(12, 2007), 10500);
lineDataset.addSeries(timeSeries2006);
lineDataset.addSeries(timeSeries2007);
JFreeChart chart = ChartFactory.createTimeSeriesChart("访问量统计时间线", "月份", "访问量", lineDataset, true, true, true);
//设置子标题
TextTitle subtitle = new TextTitle("2006/2007年度访问量对比", new Font("黑体", Font.BOLD, 12));
chart.addSubtitle(subtitle);
//设置主标题
chart.setTitle(new TextTitle("阿蜜果blog访问量统计", new Font("隶书", Font.ITALIC, 15)));
chart.setAntiAlias(true);
五.总结
本文通过详尽的实例讲述了如何利用JFreeChart开发常用的柱状图、饼图和曲线图。从这些实例中可以看出,JFreeChart是我们开发图表或报表的理想选择,它简单易用,并且容易理解,是我们开发的利刃。
责任编辑:小草