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JfreeChart连接数据库数据显示柱状图

2013-01-04 17:50 495 查看
首先编写web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>

<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>

</web-app>


 

显示柱状图代码页：index.jsp:

<%@ page contentType="text/html;charset=UTF-8"
import="java.sql.*,xuyan.model.*"%>

<%@ page
import="org.jfree.chart.ChartFactory,org.jfree.chart.JFreeChart,org.jfree.chart.plot.PlotOrientation,org.jfree.chart.servlet.ServletUtilities,org.jfree.data.category.CategoryDataset,org.jfree.data.general.DatasetUtilities,org.jfree.chart.plot.*,org.jfree.chart.labels.*,org.jfree.chart.renderer.category.BarRenderer3D,java.awt.*,org.jfree.ui.*,org.jfree.chart.axis.AxisLocation,org.jfree.chart.title.TextTitle,org.jfree.chart.axis.CategoryAxis,org.jfree.chart.axis.NumberAxis"%>

<%@ page
import="org.jfree.chart.ChartFactory,org.jfree.chart.JFreeChart,org.jfree.chart.plot.PlotOrientation,org.jfree.chart.servlet.ServletUtilities,org.jfree.data.category.DefaultCategoryDataset"%>

<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>

<body>
<%
DefaultCategoryDataset dataset = new DefaultCategoryDataset();

Connection con = null;
Statement st = null;
ResultSet rs = null;
//连接数据库
con = new ConnDB().GetConn();

st = con.createStatement();
rs = st.executeQuery("select * from AnimalNum ");
while (rs.next()) {
dataset.addValue(rs.getInt(3), "北京", rs.getString(2));
dataset.addValue(rs.getInt(5), "上海", rs.getString(4));
dataset.addValue(rs.getInt(7), "天津", rs.getString(6));
}

JFreeChart chart = ChartFactory.createBarChart("统计图", "肉类", "销量",
dataset, PlotOrientation.VERTICAL, true, true, false);

//设置字体，不然会中文乱码的

Font font = new Font("宋体", Font.BOLD, 16);

TextTitle title = new TextTitle("肉类销量统计图", font);

chart.setTitle(title);//标题

CategoryPlot plot = chart.getCategoryPlot();

NumberAxis numberaxis = (NumberAxis) plot.getRangeAxis();

CategoryAxis domainAxis = plot.getDomainAxis();

/*------设置X轴坐标上的文字-----------*/

domainAxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 11));

/*------设置X轴的标题文字------------*/

domainAxis.setLabelFont(new Font("宋体", Font.PLAIN, 12));

/*------设置Y轴坐标上的文字-----------*/

numberaxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 12));

/*------设置Y轴的标题文字------------*/

numberaxis.setLabelFont(new Font("黑体", Font.PLAIN, 12));

/*------这句代码解决了底部汉字乱码的问题-----------*/

chart.getLegend().setItemFont(new Font("宋体", Font.PLAIN, 12)); //由底部文字才加，不然会出错

// 以上为文字设置

//以下为背景设置

//设置网格背景颜色

plot.setBackgroundPaint(Color.white);

//设置网格竖线颜色

plot.setDomainGridlinePaint(Color.pink);

//设置网格横线颜色

plot.setRangeGridlinePaint(Color.pink);

//显示每个柱的数值，并修改该数值的字体属性

BarRenderer3D renderer = new BarRenderer3D();

renderer
.setBaseItemLabelGenerator(new StandardCategoryItemLabelGenerator());

renderer.setBaseItemLabelsVisible(true);

//默认的数字显示在柱子中，通过如下两句可调整数字的显示

//注意：此句很关键，若无此句，那数字的显示会被覆盖，给人数字没有显示出来的问题

renderer.setBasePositiveItemLabelPosition(new ItemLabelPosition(
ItemLabelAnchor.OUTSIDE12, TextAnchor.BASELINE_LEFT));

renderer.setItemLabelAnchorOffset(10D);

renderer.setItemLabelFont(new Font("宋体", Font.PLAIN, 12));

renderer.setItemLabelsVisible(true);

//设置每个地区所包含的平行柱的之间距离

//renderer.setItemMargin(0.3);

plot.setRenderer(renderer);

//设置地区、销量的显示位置

//将下方的“肉类”放到上方

plot.setDomainAxisLocation(AxisLocation.TOP_OR_RIGHT);

//将默认放在左边的“销量”放到右方

plot.setRangeAxisLocation(AxisLocation.BOTTOM_OR_RIGHT);

//

String filename = ServletUtilities.saveChartAsPNG(chart, 500, 300,
null, session);
String graphURL = request.getContextPath()
+ "/DisplayChart?filename=" + filename;
%>

<img src="<%=graphURL%>" width=600 height=600 border=0
usemap="#<%= filename %>">
</body>
</html>


 

显示结果：

 

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