📄 jarea.jsp
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<!--
Fig. 8.2_13: jArea.jsp
功能: JFreeChart实例13: 区域图表
-->
<%@ page language="java" contentType="image/png;charset=GB2312"
import="java.awt.*"
import="java.text.*"
import="org.jfree.chart.*"
import="org.jfree.chart.axis.*"
import="org.jfree.chart.servlet.*"
import="org.jfree.chart.plot.*"
import="org.jfree.chart.renderer.*"
import="org.jfree.chart.renderer.category.*"
import="org.jfree.chart.axis.*"
import="org.jfree.chart.entity.*"
import="org.jfree.chart.labels.*"
import="org.jfree.chart.title.*"
import="org.jfree.chart.renderer.xy.*"
import="org.jfree.data.*"
import="org.jfree.data.category.*"
import="org.jfree.ui.*"
import="org.jfree.util.*"
%>
<%!
String cities[] = {"北京", "广州", "重庆"};
String category[] = {"CPU", "主板", "内存", "硬盘", "显示卡", "显示器" };
double salesIndex;
String chartTitle = "三大城市计算机主要部件销售指数";
// 创建数据集
public CategoryDataset createDataset()
{
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
for (int i = 0; i < cities.length; i++)
{
for (int j = 0; j < category.length; j++)
{
salesIndex = .3 + Math.random();
dataset.addValue(salesIndex, cities[i], category[j]);
}
}
return dataset;
}
public JFreeChart createChart(CategoryDataset dataset)
{
// 创建图表对象
JFreeChart chart = ChartFactory.createAreaChart
(
chartTitle, // 图表标题
"统计时间:2005年1季度", // 坐标标题
"销售指数", // 坐标标题
dataset, // 定义绘制数据
PlotOrientation.VERTICAL, // 区域图的方向
true, // 定义图表是否包含图例
true, // 定义图表是否包含提示
false // 定义图表是否包含URL
);
return chart;
}
%>
<%
// 创建一个 500X375 的图像
int width=500, height=375;
CategoryDataset dataset = createDataset();
JFreeChart chart = createChart(dataset);
// 开始自定义图表绘制的相关属性
// 设置整个图表的背景颜色
GradientPaint bgGP = new GradientPaint(0, 0, Color.YELLOW,
0, height, Color.WHITE, false);
chart.setBackgroundPaint(bgGP);
// 设置图表对象的绘制属性
CategoryPlot plot = chart.getCategoryPlot();
plot.setForegroundAlpha(0.5f);
plot.setBackgroundPaint(Color.LIGHT_GRAY);
plot.setDomainGridlinesVisible(true);
plot.setDomainGridlinePaint(Color.WHITE);
plot.setRangeGridlinesVisible(true);
plot.setRangeGridlinePaint(Color.WHITE);
// 设置横轴上的度量值文字的绘制角度及图表绘制边界
CategoryAxis domainAxis = plot.getDomainAxis();
domainAxis.setCategoryLabelPositions(CategoryLabelPositions.UP_45);
domainAxis.setLowerMargin(0.0);
domainAxis.setUpperMargin(0.0);
// 设置纵轴上的度量值(数字)的显示风格
NumberAxis rangeAxis = (NumberAxis)plot.getRangeAxis();
DecimalFormat df = new DecimalFormat("###0.00%");
NumberTickUnit ntu = new NumberTickUnit(0.1, df);
rangeAxis.setTickUnit(ntu) ;
// 结束自定义图表绘制的相关属性
ChartRenderingInfo info =
new ChartRenderingInfo(new StandardEntityCollection());
// 设置图片生成格式
String fileName =
ServletUtilities.saveChartAsPNG(chart, width, height, info, session);
// 设置图片生成路径
String graphURL =
request.getContextPath() + "/servlet/DisplayChart?filename=" + fileName;
%>
<HTML>
<HEAD>
<TITLE><%=chartTitle%></TITLE>
</HEAD>
<BODY>
<P ALIGN="CENTER">
<img src="<%=graphURL %>" border="1" >
</P>
</BODY>
</HTML>
<%
/**************************************************************************
* (C) Copyright 2004-2005 by Jingkui Zhong(钟京馗) and Huan Tang(唐桓). *
* All Rights Reserved. *
* *
* DISCLAIMER: The authors of this code have used their *
* best efforts in preparing the code. These efforts include the *
* development, research, and testing of the theories and programs *
* to determine their effectiveness. The authors and publisher make *
* no warranty of any kind, expressed or implied, with regard to these *
* programs or to the documentation contained in these codes. The authors *
* shall not be liable in any event for incidental or consequential *
* damages in connection with, or arising out of, the furnishing, *
* performance, or use of these programs. *
**************************************************************************/
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