jfreechart简单应用

谁践踏了优雅 2022-08-17 14:19 162阅读 0赞

JFreeChart主要用来各种各样的图表，这些图表包括：饼图、柱状图(普通柱状图以及堆栈柱状图)、线图、区域图、分布图、混合图、甘特图以及一些仪表盘等等

([源代码下载][Link 1])

示例程序运用的jar包：

*  jcommon-1.0.17.jar
 *  jfreechart-1.0.14.jar

1:普通柱状图

这是程序调用CategoryDataset dataset = getDataSet2(); 后所生产的图片

![2012051916462077.jpg][]

BarChartDemo.java柱状图代码

![复制代码][copycode.gif]

/** 
    * 该类用于演示最简单的柱状图生成
    * @author Winter Lau 
    */ 
    public class BarChartDemo { 
        public static void main(String[] args) throws IOException{ 
            
            CategoryDataset dataset = getDataSet2(); 
            JFreeChart chart = ChartFactory.createBarChart3D( 
                               "水果产量图", // 图表标题
                               "水果", // 目录轴的显示标签
                               "产量", // 数值轴的显示标签
                                dataset, // 数据集
                                PlotOrientation.VERTICAL, // 图表方向：水平、垂直
                                true,  // 是否显示图例(对于简单的柱状图必须是 false)
                                false, // 是否生成工具
                                false  // 是否生成 URL 链接
                                ); 
            //中文乱码
            CategoryPlot categoryplot = (CategoryPlot) chart.getPlot();
            NumberAxis numberaxis = (NumberAxis) categoryplot.getRangeAxis();  
            CategoryAxis domainAxis = categoryplot.getDomainAxis();  
            TextTitle textTitle = chart.getTitle();
            textTitle.setFont(new Font("黑体", Font.PLAIN, 20));      
            domainAxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 11));  
            domainAxis.setLabelFont(new Font("宋体", Font.PLAIN, 12));  
            numberaxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 12));  
            numberaxis.setLabelFont(new Font("黑体", Font.PLAIN, 12));  
            chart.getLegend().setItemFont(new Font("宋体", Font.PLAIN, 12));
                               
            FileOutputStream fos_jpg = null; 
            try { 
                fos_jpg = new FileOutputStream("D:\\BarChart.jpg"); 
                ChartUtilities.writeChartAsJPEG(fos_jpg, 1.0f,chart,400,300,null); 
            } finally { 
                try { 
                    fos_jpg.close(); 
                } catch (Exception e) {} 
            } 
        } 
        /** 
        * 获取一个演示用的简单数据集对象
        * @return 
        */ 
        private static CategoryDataset getDataSet() { 
            DefaultCategoryDataset dataset = new DefaultCategoryDataset(); 
            dataset.addValue(100, "", "苹果"); 
            dataset.addValue(200, "", "梨子"); 
            dataset.addValue(300, "", "葡萄"); 
            dataset.addValue(400, "", "香蕉"); 
            dataset.addValue(500, "", "荔枝"); 
            return dataset; 
        } 
        /** 
        * 获取一个演示用的组合数据集对象
        * @return 
        */ 
        private static CategoryDataset getDataSet2() { 
            DefaultCategoryDataset dataset = new DefaultCategoryDataset(); 
            dataset.addValue(100, "北京", "苹果"); 
            dataset.addValue(100, "上海", "苹果"); 
            dataset.addValue(100, "广州", "苹果"); 
            dataset.addValue(200, "北京", "梨子"); 
            dataset.addValue(200, "上海", "梨子"); 
            dataset.addValue(200, "广州", "梨子"); 
            dataset.addValue(300, "北京", "葡萄"); 
            dataset.addValue(300, "上海", "葡萄"); 
            dataset.addValue(300, "广州", "葡萄"); 
            dataset.addValue(400, "北京", "香蕉"); 
            dataset.addValue(400, "上海", "香蕉"); 
            dataset.addValue(400, "广州", "香蕉"); 
            dataset.addValue(500, "北京", "荔枝"); 
            dataset.addValue(500, "上海", "荔枝"); 
            dataset.addValue(500, "广州", "荔枝"); 
            return dataset; 
        } 
    }

![复制代码][copycode.gif]

2：饼状图

![2012051916560227.jpg][]

PieChartDemo.java饼状图源代码

![复制代码][copycode.gif]

/**
     * 用于演示饼图的生成
     */
    public class PieChartDemo {
        public static void main(String[] args) throws IOException {
            DefaultPieDataset data = getDataSet();
            JFreeChart chart = ChartFactory.createPieChart3D("水果产量图", // 图表标题
                    data, // 数据集
                    true, // 是否显示图例(对于简单的柱状图必须是 false)
                    false, // 是否生成工具
                    false // 是否生成 URL 链接
                    );
    
            //中文乱码
            PiePlot3D plot = (PiePlot3D) chart.getPlot();
            plot.setLabelFont(new Font("黑体", Font.PLAIN, 20));
            TextTitle textTitle = chart.getTitle();
            textTitle.setFont(new Font("黑体", Font.PLAIN, 20));
            chart.getLegend().setItemFont(new Font("宋体", Font.PLAIN, 12));
    
            // 写图表对象到文件，参照柱状图生成源码
            FileOutputStream fos_jpg = null;
            try {
                fos_jpg = new FileOutputStream("D:\\Pie3DChart.jpg");
                ChartUtilities.writeChartAsJPEG(fos_jpg, 1.0f, chart, 400, 300,
                        null);
            } finally {
                try {
                    fos_jpg.close();
                } catch (Exception e) {
                }
            }
        }
    
        /**
         * 获取一个演示用的简单数据集对象
         * 
         * @return
         */
        private static DefaultPieDataset getDataSet() {
            DefaultPieDataset dataset = new DefaultPieDataset();
            dataset.setValue("苹果", 100);
            dataset.setValue("梨子", 200);
            dataset.setValue("葡萄", 300);
            dataset.setValue("香蕉", 400);
            dataset.setValue("荔枝", 500);
            return dataset;
        }
    }

![复制代码][copycode.gif]

其他的图表类型暂时不写了，其实写法也差不多。这里注意两种图形的中文乱码解决方法是不一样的，具体查看源代码中的红色部分

3：将数据库的内容用图形表示出来

![2012051917034174.jpg][]

index.jsp

showJfreeChart.jsp

<body>
        <center>
        <img alt="" src="<%=path %>/reports/productSales.jpg">
        </center>
      </body>

ShowChartServlet.java

![复制代码][copycode.gif]

public class ShowChartServlet extends HttpServlet {
    
        /**
         * 获取一个演示用的组合数据集对象
         * 
         * @return
         */
        private static CategoryDataset getDataSet() {
            DefaultCategoryDataset dataset = new DefaultCategoryDataset();
            // 从数据库中获取
            Connection conn = null;
            PreparedStatement ps = null;
            ResultSet rs = null;
            try {
                Class.forName("com.mysql.jdbc.Driver"); // 加载驱动程序
                conn = DriverManager
                        .getConnection(
                                "jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=utf8",
                                "root", "root");
                ps = conn.prepareStatement("select p.name, count(pcount) from product p join salesitem si on (p.id = si.productid) group by p.id");
                rs = ps.executeQuery();
                while (rs.next()) {
                    dataset.addValue(rs.getInt(2), "", rs.getString(1));
                }
                rs.close();
                rs = null;
            } catch (SQLException e) {
                e.printStackTrace();
            }catch (ClassNotFoundException e) {
                e.printStackTrace();
            }
            finally {
                if(ps != null){
                    try {
                        ps.close();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                }
                if(conn != null){
                    try {
                        conn.close();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                }
    
            }
    
            return dataset;
        }
    
        public void doGet(HttpServletRequest request, HttpServletResponse response)
                throws ServletException, IOException {
    
            CategoryDataset dataset = getDataSet(); 
            JFreeChart chart = ChartFactory.createBarChart3D( 
                               "产品销量图", // 图表标题
                               "产品", // 目录轴的显示标签
                               "销量", // 数值轴的显示标签
                                dataset, // 数据集
                                PlotOrientation.VERTICAL, // 图表方向：水平、垂直
                                true,  // 是否显示图例(对于简单的柱状图必须是 false)
                                false, // 是否生成工具
                                false  // 是否生成 URL 链接
                                ); 
            //中文乱码
            CategoryPlot categoryplot = (CategoryPlot) chart.getPlot();
            NumberAxis numberaxis = (NumberAxis) categoryplot.getRangeAxis();  
            CategoryAxis domainAxis = categoryplot.getDomainAxis();  
            TextTitle textTitle = chart.getTitle();
            textTitle.setFont(new Font("黑体", Font.PLAIN, 20));      
            domainAxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 11));  
            domainAxis.setLabelFont(new Font("宋体", Font.PLAIN, 12));  
            numberaxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 12));  
            numberaxis.setLabelFont(new Font("黑体", Font.PLAIN, 12));  
            chart.getLegend().setItemFont(new Font("宋体", Font.PLAIN, 12));
                               
            FileOutputStream fos_jpg = null; 
            try { 
                fos_jpg = new FileOutputStream("E:\\Workspaces\\MyEclipse 9\\WebProjects\\JFreeChart\\WebRoot\\reports\\productSales.jpg"); 
                ChartUtilities.writeChartAsJPEG(fos_jpg, 1.0f,chart,400,300,null); 
                 String path = this.getServletContext().getContextPath();
                 System.out.println(path+"mmmmmmmmmmm");
                this.getServletContext().getRequestDispatcher("/showJfreeChart.jsp").forward(request, response);
            } finally { 
                try { 
                    fos_jpg.close(); 
                } catch (Exception e) {} 
            } 
        }
    
    }

![复制代码][copycode.gif]

[Link 1]: http://files.cnblogs.com/ITtangtang/JFreeChart.rar
[2012051916462077.jpg]: /images/20220731/cfa4ac0c1ac0496ca56fa513fccafd9b.png
[copycode.gif]: /images/20220731/4b16f5afadfa44eda2280795b05e2264.png
[2012051916560227.jpg]: /images/20220731/fcbe28245a994ea7bbb4fbec516465e2.png
[2012051917034174.jpg]: /images/20220731/cab7dc3afe3b4555888fd09ecfce94e9.png