一、jFreeChart产生图形的流程
创建一个数据源(dataset)来包含将要在图形中显示的数据>>创建一个 JFreeChart 对象来代表要显示的图形
>>把图形输出
重要的类和接口:
org.jfree.data.general.Dataset 所有数据源类都要实现的接口
org.jfree.chart.ChartFactory 由它来产生 JFreeChart 对象
org.jfree.chart.JFreeChart 所有对图形的调整都是通过它噢!!
org.jfree.chart.plot.Plot 通过JFreeChart 对象获得它,然后再通过它对图形外部部分(例:坐标轴)调整
注意:它有很多子类,一般都下嗍造型到它的子类!
org.jfree.chart.renderer.AbstractRenderer 通过JFreeChart 对象获得它,然后再通过它对图形内部部分
(例:折线的类型)调整。同样,针对不同类型的报表图,它有
着不同的子类实现!在下面我们简称它为 Renderer
下面我们结合不同类型的图形来具体分析这个流程。
二、饼图
饼图的dataset 一般是用PieDataset 接口,具体实现类是 DefaultPieDataset
1、创建一个数据源(dataset):
private static PieDataset createDataset()
{
DefaultPieDataset defaultpiedataset = new DefaultPieDataset(); //注意是DefaultPieDataset!!
defaultpiedataset.setValue(”One”, new Double(43.200000000000003D));
defaultpiedataset.setValue(”Two”, new Double(10D));
defaultpiedataset.setValue(”Three”, new Double(27.5D));
defaultpiedataset.setValue(”Four”, new Double(17.5D));
return defaultpiedataset;
}
2、由ChartFactory 产生 JFreeChart 对象
private static JFreeChart createChart(PieDataset piedataset)
{
JFreeChart jfreechart = ChartFactory.createPieChart(”Pie Chart Demo 1″, //图形标题名称
piedataset, // dataset
true, // legend?
true, // tooltips?
false); //URLs?
PiePlot pieplot = (PiePlot)jfreechart.getPlot(); //通过JFreeChart 对象获得 plot:PiePlot!!
pieplot.setNoDataMessage(”No data available”); // 没有数据的时候显示的内容
return jfreechart;
}
一些重要的方法:
pieplot.setExplodePercent(0,0.3D) //把Lable 为”One” 的那一块”挖”出来30%
3、输出略
三、柱状图
柱状图的dataset 一般是用CatagoryDataset接口(具体实现类是DefaultCategoryDataset),也会用 IntervalXYDataset
接口
1、创建一个数据源(dataset):
private static CategoryDataset createDataset()
{
String series1 = “First”;
String series2 = “Second”;
String series3 = “Third”;
String category1 = “Category 1″;
String category2 = “Category 2″;
String category3 = “Category 3″;
String category4 = “Category 4″;
String category5 = “Category 5″;
DefaultCategoryDataset defaultcategorydataset = new DefaultCategoryDataset();
defaultcategorydataset.addValue(1.0D, series1, category1);
defaultcategorydataset.addValue(4D, series1, category2);
defaultcategorydataset.addValue(3D, series1, category3);
defaultcategorydataset.addValue(5D, series1, category4);
defaultcategorydataset.addValue(5D, series1, category5);
defaultcategorydataset.addValue(5D, series2, category1);
defaultcategorydataset.addValue(7D, series2, category2);
defaultcategorydataset.addValue(6D, series2, category3);
defaultcategorydataset.addValue(8D, series2, category4);
defaultcategorydataset.addValue(4D, series2, category5);
defaultcategorydataset.addValue(4D, series3, category1);
defaultcategorydataset.addValue(3D, series3, category2);
defaultcategorydataset.addValue(2D, series3, category3);
defaultcategorydataset.addValue(3D, series3, category4);
defaultcategorydataset.addValue(6D, series3, category5);
return defaultcategorydataset;
}
2、由ChartFactory 产生 JFreeChart 对象
private static JFreeChart createChart(CategoryDataset categorydataset)
{
JFreeChart jfreechart = ChartFactory.createBarChart(”Bar Chart Demo”, //图形标题名称
“Category”,//domain 轴 Lable
这里先简单理解为横坐标Lable好了
“Value”, //range 轴 Lable
这里也先简单理解为纵坐标Lable好了
categorydataset, // dataset
PlotOrientation.VERTICAL, //垂直显示
true, // legend?
true, // tooltips?
false); //URLs?
jfreechart.setBackgroundPaint(Color.white); //设定背景色为白色
CategoryPlot categoryplot = jfreechart.getCategoryPlot(); //获得 plot:CategoryPlot!!
categoryplot.setBackgroundPaint(Color.lightGray); //设定图表数据显示部分背景色
categoryplot.setDomainGridlinePaint(Color.white); //横坐标网格线白色
categoryplot.setDomainGridlinesVisible(true); //可见
categoryplot.setRangeGridlinePaint(Color.white); //纵坐标网格线白色
//下面两行使纵坐标的最小单位格为整数
NumberAxis numberaxis = (NumberAxis)categoryplot.getRangeAxis();
numberaxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
BarRenderer barrenderer = (BarRenderer)categoryplot.getRenderer(); //获得renderer 注意这里是下嗍造型
到BarRenderer!!
barrenderer.setDrawBarOutline(false); // Bar的外轮廓线不画
GradientPaint gradientpaint = new GradientPaint(0.0F, 0.0F, Color.blue,
0.0F, 0.0F, new Color(0, 0, 64)); //设定特定颜色
GradientPaint gradientpaint1 = new GradientPaint(0.0F, 0.0F, Color.green,
0.0F, 0.0F, new Color(0, 64, 0));
GradientPaint gradientpaint2 = new GradientPaint(0.0F, 0.0F, Color.red,
0.0F, 0.0F, new Color(64, 0, 0));
barrenderer.setSeriesPaint(0, gradientpaint); //给series1 Bar设定上面定义的颜色
barrenderer.setSeriesPaint(1, gradientpaint1); //给series2 Bar 设定上面定义的颜色
barrenderer.setSeriesPaint(2, gradientpaint2); //给series3 Bar 设定上面定义的颜色
CategoryAxis categoryaxis = categoryplot.getDomainAxis(); //横轴上的 Lable 45度倾斜
categoryaxis.setCategoryLabelPositions(CategoryLabelPositions.UP_45);
return jfreechart;
}
一些重要的方法:(增加一块标记)
IntervalMarker intervalmarker = new IntervalMarker(4.5D, 7.5D);
intervalmarker.setLabel(”Target Range”);
intervalmarker.setLabelFont(new Font(”SansSerif”, 2, 11));
intervalmarker.setLabelAnchor(RectangleAnchor.LEFT);
intervalmarker.setLabelTextAnchor(TextAnchor.CENTER_LEFT);
intervalmarker.setPaint(new Color(222, 222, 255, 128));
categoryplot.addRangeMarker(intervalmarker, Layer.BACKGROUND);
四、折线图
折线图的dataset 两种CatagoryDataset接口(具体实现类是DefaultCategoryDataset),XYDataset 接口
1、CatagoryDataset接口:
A、创建一个数据源(dataset):
private static CategoryDataset createDataset()
{
String series1 = “First”;
String series2 = “Second”;
String series3 = “Third”;
String type1 = “Type 1″;
String type2 = “Type 2″;
String type3 = “Type 3″;
String type4 = “Type 4″;
String type5 = “Type 5″;
String type6 = “Type 6″;
String type7 = “Type 7″;
String type8 = “Type 8″;
DefaultCategoryDataset defaultcategorydataset = new DefaultCategoryDataset();
defaultcategorydataset.addValue(1.0D, series1, type1);
defaultcategorydataset.addValue(4D, series1, type2);
defaultcategorydataset.addValue(3D, series1, type3);
defaultcategorydataset.addValue(5D, series1, type4);
defaultcategorydataset.addValue(5D, series1, type5);
defaultcategorydataset.addValue(7D, series1, type6);
defaultcategorydataset.addValue(7D, series1, type7);
defaultcategorydataset.addValue(8D, series1, type8);
defaultcategorydataset.addValue(5D, series2, type1);
defaultcategorydataset.addValue(7D, series2, type2);
defaultcategorydataset.addValue(6D, series2, type3);
defaultcategorydataset.addValue(8D, series2, type4);
defaultcategorydataset.addValue(4D, series2, type5);
defaultcategorydataset.addValue(4D, series2, type6);
defaultcategorydataset.addValue(2D, series2, type7);
defaultcategorydataset.addValue(1.0D, series2, type8);
defaultcategorydataset.addValue(4D, series3, type1);
defaultcategorydataset.addValue(3D, series3, type2);
defaultcategory