JFreeChart 一些特性

柱狀圖高級特性

BarRenderer3D renderer = new BarRenderer3D();
renderer.setBaseOutlinePaint(Color.BLACK);
//設置 Wall 的顏色
renderer.setWallPaint(Color.gray);
//設置每種水果代表的柱的顏色
renderer.setSeriesPaint(0, new Color(0, 0, 255));
renderer.setSeriesPaint(1, new Color(0, 100, 255));
renderer.setSeriesPaint(2, Color.GREEN);
//設置每種水果代表的柱的 Outline 顏色
renderer.setSeriesOutlinePaint(0, Color.BLACK);
renderer.setSeriesOutlinePaint(1, Color.BLACK);
renderer.setSeriesOutlinePaint(2, Color.BLACK);
//設置每個地區所包含的平行柱的之間距離
renderer.setItemMargin(0.1);
//顯示每個柱的數值，並修改該數值的字體屬性
renderer.setItemLabelGenerator(new StandardCategoryItemLabelGenerator());
renderer.setItemLabelFont(new Font("黑體",Font.PLAIN,12));
renderer.setItemLabelsVisible(true);

 

完整範例

　　前面都是一些代碼片段，現在把這些片段組合成一個完整範例。

<%@ page contentType="text/html;charset=GBK"%>
<%@ page import="java.awt.Color,
                java.awt.Font,
                org.jfree.chart.ChartFactory,
                org.jfree.chart.JFreeChart,
                org.jfree.chart.plot.PlotOrientation,
                org.jfree.chart.servlet.ServletUtilities,
                org.jfree.data.CategoryDataset,
                org.jfree.data.DatasetUtilities,
                org.jfree.chart.plot.CategoryPlot,
                org.jfree.chart.axis.CategoryAxis,
                org.jfree.chart.axis.Axis,
                org.jfree.chart.renderer.BarRenderer3D,
                org.jfree.chart.labels.StandardCategoryItemLabelGenerator,
                org.jfree.chart.axis.AxisLocation"%>
<%
double[][] data = new double[][] {{672, 766, 223, 540, 126},{325, 521, 210, 340, 106},{332, 256, 523, 240, 526}};
String[] rowKeys = {"蘋果","梨子","葡萄"};
String[] columnKeys = {"北京","上海","廣州","成都","深圳"};
CategoryDataset dataset = DatasetUtilities.createCategoryDataset(rowKeys, columnKeys, data);

JFreeChart chart = ChartFactory.createBarChart3D("水果銷量圖統計",
                  null,
                  null,
                  dataset,
                  PlotOrientation.VERTICAL,
                  true,false,false);
chart.setBackgroundPaint(Color.WHITE);
CategoryPlot plot = chart.getCategoryPlot();

CategoryAxis domainAxis = plot.getDomainAxis();
domainAxis.setVerticalCategoryLabels(false);
plot.setDomainAxis(domainAxis);

Axis rangeAxis = plot.getRangeAxis();
//設置最高的一個 Item 與圖片頂端的距離
rangeAxis.setUpperMargin(0.15);
//設置最低的一個 Item 與圖片底端的距離
rangeAxis.setLowerMargin(0.15);
plot.setRangeAxis(rangeAxis);

BarRenderer3D renderer = new BarRenderer3D();
renderer.setBaseOutlinePaint(Color.BLACK);
//設置 Wall 的顏色
renderer.setWallPaint(Color.gray);
//設置每種水果代表的柱的顏色
renderer.setSeriesPaint(0, new Color(0, 0, 255));
renderer.setSeriesPaint(1, new Color(0, 100, 255));
renderer.setSeriesPaint(2, Color.GREEN);
//設置每個地區所包含的平行柱的之間距離
renderer.setItemMargin(0.1);
//顯示每個柱的數值，並修改該數值的字體屬性
renderer.setItemLabelGenerator(new StandardCategoryItemLabelGenerator());
renderer.setItemLabelsVisible(true);
plot.setRenderer(renderer);

//設置柱的透明度
plot.setForegroundAlpha(0.6f);
//設置地區、銷量的顯示位置
plot.setDomainAxisLocation(AxisLocation.TOP_OR_RIGHT);
plot.setRangeAxisLocation(AxisLocation.BOTTOM_OR_RIGHT);

String filename = ServletUtilities.saveChartAsPNG(chart, 500, 300, null, session);
String graphURL = request.getContextPath() + "/servlet/DisplayChart?filename=" + filename;
%s>
<img src="<%= graphURL %>" width=500 height=300 border=0 usemap="#<%= filename %>">