接上回JFREECHART

最新推荐文章于 2025-08-13 13:36:43 发布

原创最新推荐文章于 2025-08-13 13:36:43 发布 · 393 阅读

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文章标签：

#jfreechart #dataset #string #plot #pig #apple

本文介绍如何使用Java和JFreeChart库创建带有3D效果的柱状图，并展示了一个具体的示例，包括如何设置标题、字体样式以及如何保存图表为PNG格式。

上面的这个柱状图比较简单，稍显单调，在有些情况下，我们需要用不同颜色来表示不同的种类，或者在种类上标上具体数值，亦或需要加上3D水晶效果。下面让我们来做更深一步的探讨。接下来让我们看一个用不同颜色来表示不通种类的例子。在WebRoot的bar目录下新建sample2.jsp页面，将其代码修改如下：

<%@ page contentType="text/html;charset=GBK"%>

<%@ page import="org.jfree.chart.ChartFactory,
org.jfree.chart.JFreeChart,
org.jfree.chart.plot.PlotOrientation,
org.jfree.chart.plot.CategoryPlot,
org.jfree.chart.axis.*,
org.jfree.chart.servlet.ServletUtilities,
java.awt.*,
org.jfree.chart.title.TextTitle,
org.jfree.data.category.CategoryDataset,
org.jfree.data.general.DatasetUtilities"%>

<%
double[][] data = new double[][] {{1310}, {720}, {1130}, {440},{563},{888}};
String[] rowKeys = { "pig", "beef", "chicken", "fish", "apple", "orange"};
String[] columnKeys = {""};
CategoryDataset dataset = DatasetUtilities.createCategoryDataset(rowKeys, columnKeys, data);
JFreeChart chart = ChartFactory.createBarChart3D("广州肉类销量统计图",
"type",
"amount",
dataset,
PlotOrientation.VERTICAL,
true,
false,
false);
CategoryPlot plot=chart.getCategoryPlot();
CategoryAxis domainAxis=plot.getDomainAxis();
domainAxis.setLabelFont(new Font("黑体",Font.BOLD,14));
domainAxis.setTickLabelFont(new Font("宋体",Font.BOLD,12));
ValueAxis rangeAxis=plot.getRangeAxis();
rangeAxis.setLabelFont(new Font("黑体",Font.BOLD,15));
TextTitle textTitle = chart.getTitle();
textTitle.setFont(new Font("黑体",Font.BOLD,15));
String filename = ServletUtilities.saveChartAsPNG(chart, 500, 300, null, session);
String graphURL = request.getContextPath() + "/DisplayChart?filename=" + filename;
%>
<img src="<%= graphURL %>" width=500 height=300 border=0 usemap="#<%= filename %>">