jFreeChart学习笔记（一）——报表demo示例

一时失言乱红尘 2022-05-09 01:34 289阅读 0赞

第一步：

新建一个Dynamic Web Project工程

第二步：

导入jar包

![70][]

第三步：web.xml配置

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

第四步：java类生成指定图表

package com.java1234.chart.bar;
    
    import javax.servlet.http.HttpSession;
    
    import org.jfree.chart.ChartFactory;
    import org.jfree.chart.JFreeChart;
    import org.jfree.chart.plot.PlotOrientation;
    import org.jfree.chart.servlet.ServletUtilities;
    import org.jfree.data.category.DefaultCategoryDataset;
    
    public class BarChart1 {
    	
    	public static String getBarChart(HttpSession session)throws Exception {
    		DefaultCategoryDataset dataset = new DefaultCategoryDataset();
    		dataset.addValue(510, "深圳", "苹果");
    		dataset.addValue(320, "深圳", "香蕉");
    		dataset.addValue(580, "深圳", "橘子");
    		dataset.addValue(390, "深圳", "梨子");
    		JFreeChart chart = ChartFactory.createBarChart3D("水果销售统计图", "水果", "销售", dataset,
    				PlotOrientation.VERTICAL, true, true, true);
    		String fileName = ServletUtilities.saveChartAsPNG(chart, 700, 500, null ,session);
    		return fileName;
    	}
    	
    }

第五步：jsp文件

<%@page import="com.java1234.chart.bar.BarChart1"%>
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
    </head>
    <body>
    <%
    	String fileName = BarChart1.getBarChart(session);
    	System.out.println(fileName);
    %>
    <img src="DisplayChart?filename=<%=fileName %>" width="700" height="500" border="0">
    </body>
    </html>

第六步：测试  [http://localhost:8080/jFreeChartDemo/barChart.jsp][http_localhost_8080_jFreeChartDemo_barChart.jsp]

![70 1][]

[70]: /images/20220509/bb9e1f99af2a437f8d39fea91eb8a05e.png
[http_localhost_8080_jFreeChartDemo_barChart.jsp]: http://localhost:8080/jFreeChartDemo/barChart.jsp
[70 1]: /images/20220509/cd8231d1ef15486ab808d9c97312d781.png