JavaWeb图形报表柱状图
步骤说明:
1,导入log4j.jar,jfreechart-0.9.18.jar,jcommon-0.9.3.jar三个jar包
2,在某个包中写入BarChart .java类
package com.mengya.util;
import java.awt.Color;
import java.io.PrintWriter;
import javax.servlet.http.HttpSession;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartRenderingInfo;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.AxisLocation;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.entity.StandardEntityCollection;
import org.jfree.chart.labels.StandardCategoryItemLabelGenerator;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.BarRenderer3D;
import org.jfree.chart.servlet.ServletUtilities;
import org.jfree.data.DefaultCategoryDataset;
public class BarChart {
private DefaultCategoryDataset dataset = new DefaultCategoryDataset();
public void setValue(int value, String rowKey, String columnKey) {
dataset.setValue(value, rowKey, columnKey);
}
public String generateBarChart(String title, HttpSession session,PrintWriter pw,int width,int heigth) {
String filename = null;
try {
JFreeChart chart = ChartFactory
.createBarChart3D(title, 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);
ValueAxis rangeAxis = plot.getRangeAxis();
// 设置最高的一个 Item 与图片顶端的距离
rangeAxis.setUpperMargin(0.15);
// 设置最低的一个 Item 与图片底端的距离
rangeAxis.setLowerMargin(0.15);
plot.setRangeAxis(rangeAxis);
BarRenderer3D renderer = new BarRenderer3D();
renderer.setBaseOutlinePaint(Color.BLACK);
// 设置 Wall 的颜色
renderer.setWallPaint(Color.gray);
// 设置每种水果代表的柱的颜色
renderer.setSeriesPaint(0, new Color(0, 0, 255));
renderer.setSeriesPaint(1, new Color(0, 100, 255));
renderer.setSeriesPaint(2, Color.GREEN);
// 设置每个地区所包含的平行柱的之间距离
renderer.setItemMargin(0.1);
// 显示每个柱的数值，并修改该数值的字体属性
//renderer.setItemLabelGenerator(new StandardCategoryItemLabelGenerator());
renderer.setItemLabelsVisible(true);
plot.setRenderer(renderer);
// 设置柱的透明度
plot.setForegroundAlpha(0.6f);
// 设置地区、销量的显示位置
plot.setDomainAxisLocation(AxisLocation.TOP_OR_RIGHT);
plot.setRangeAxisLocation(AxisLocation.BOTTOM_OR_RIGHT);
ChartRenderingInfo info = new ChartRenderingInfo(
new StandardEntityCollection());
filename = ServletUtilities.saveChartAsPNG(chart, width, heigth,
info, session);
ChartUtilities.writeImageMap(pw, filename, info);
pw.flush();
} catch (Exception e) {
e.printStackTrace();
}
return filename;
}
}
3,配置web.xml,在web.xml中添加如下内空:
<servlet>
<servlet-name>DisplayChart</servlet-name>
<servlet-class>
org.jfree.chart.servlet.DisplayChart
</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>DisplayChart</servlet-name>
<url-pattern>/DisplayChart</url-pattern>
</servlet-mapping>
4,在要显示图片的jsp中添加内容:
<%@ page language="java" import="java.util.*,com.mengya.util.BarChart"
pageEncoding="gbk"%>
<%@ page import="java.io.PrintWriter"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>柱形图</title>
</head>
<body>
<%
BarChart bch = new BarChart();
//double[] data = { 85, 156, 179.5, 211, 123 };
//String[] labels = { "Mon", "Tue", "Wed", "Thu", "Fri" };
//for (int i = 0; i < data.length; i++) {
// bch.setValue((int) data[i], "张明学", labels[i]);
//}
//第一组
bch.setValue(200,"苹果","武汉");
bch.setValue(400,"香蕉","武汉");
bch.setValue(500,"橘子","武汉");
bch.setValue(300,"梨子","武汉");
//第二组
bch.setValue(400,"苹果","黄冈");
bch.setValue(300,"香蕉","黄冈");
bch.setValue(100,"橘子","黄冈");
bch.setValue(300,"梨子","黄冈");
//第三组
bch.setValue(600,"苹果","A");
bch.setValue(300,"香蕉","A");
bch.setValue(400,"橘子","A");
bch.setValue(200,"梨子","A");
//说明:bch.setValue(int a,String b,String c)其中参数c是该组的名字。最组的名字最好是不一样的！
String filename = bch.generateBarChart("水果比图", session,
new PrintWriter(out),700,500);
String url = request.getContextPath() + "/DisplayChart?filename="
+ filename;
%>
<table align="center" border="0">
<tr>
<td>
<P ALIGN="CENTER">
<img src="<%=url%>" width=700 height=500 border=1
usemap="#<%=filename%>">
</p>
</td>
</tr>
</table>
</body>
</html>