JFreeChart 制作柱状图分析数据

古城微笑少年丶 2022-06-12 03:15 201阅读 0赞

代码：

ChartHistogram.java

package com.utils;
    
    
    import java.awt.Font;
    
    import org.jfree.chart.ChartFactory;
    import org.jfree.chart.JFreeChart;
    import org.jfree.chart.plot.PlotOrientation;
    import org.jfree.data.category.CategoryDataset;
    import org.jfree.data.category.DefaultCategoryDataset;
    
    public class ChartHistogram {
      /* 
       * 创建要导入的数据集合
       */
    	public static CategoryDataset createDataSet(){
    		DefaultCategoryDataset dataset = new DefaultCategoryDataset();
    		//向数据集合中添加数据,此处可以转为数据库查询操作
    		dataset.addValue(11, "用户修改次数", "杨旭");
    		dataset.addValue(6, "用户修改次数", "李英杰");
    		dataset.addValue(4, "用户修改次数", "陈朋");
    		dataset.addValue(2, "用户修改次数", "XXX");
    		return dataset;
    	}
    	
    	//创建JFreeChart对象
    	public static JFreeChart createChart(){
    	
         //通过ChartFactory 创建JFreeChart
    	 JFreeChart chart = ChartFactory.createBarChart3D("员工修改参数次数统计", "员工姓名", "修改次数(次)", createDataSet(), PlotOrientation.VERTICAL, false, false, false);
    	 chart.getTitle().setFont(new Font("隶书", Font.BOLD, 25));
    	 return chart;
    	}
    }

ChartHistogram.jsp

<%@page import="com.utils.ChartHistogram"%>
    <%@page import="org.jfree.chart.servlet.ServletUtilities"%>
    <%@ 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>JFreeChart显示柱状图</title>
    </head>
    <body>
    <%
      String fileName = ServletUtilities.saveChartAsJPEG( ChartHistogram.createChart(), 580, 380, session);
    %>
    <div align="center">
       <img alt="员工修改参数次数统计图" src="DisplayChart?filename=<%=fileName %>" border="1"><br/><br/><br/>
       <a href="${pageContext.request.contextPath }/jsp/manager/AllParameter.jsp">返回上一级目录</a>
    </div>
    </body>
    </html>

截图：

![Center][]

[Center]: /images/20220612/b6c7312ab1a4498885ea14be2285f672.png