Jfreechart DialPlot(二)时钟表



                             Jfreechart时钟表DialPlot图形例子

    在做仪表盘的时候，想着DialPlot本身就是个钟表图，可以当仪表盘用，也能生成钟表，所以就试了下，结果还可以.它和仪表盘一样分三步：1.导包 2.创建一个web项目 3.在web.xml中配置

web.xml中配置如下：

<?xmlversion="1.0"encoding="UTF-8"?>

<web-appversion="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">

    <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>/servlet/DisplayChart</url-pattern>   

   </servlet-mapping>

</web-app>

下面是在JSP页面实现代码，如下例子所示：

<%@pagecontentType="text/html;charset=UTF-8"%

<%@page import="org.jfree.chart.JFreeChart,

   org.jfree.chart.servlet.ServletUtilities,

   org.jfree.data.general.DefaultValueDataset,

   org.jfree.experimental.chart.plot.dial.*,

   java.awt.*,java.io.*,org.jfree.chart.ChartUtilities,

   org.jfree.ui.StandardGradientPaintTransformer,

   org.jfree.experimental.chart.plot.dial.DialPointer.*,

   org.jfree.ui.GradientPaintTransformType"

%>

<%

   //创建时钟和分钟的数据集

   DefaultValueDataset hoursDataset = new DefaultValueDataset(8D);

   DefaultValueDataset minitesDs = new DefaultValueDataset(35D);

   //设置钟表图形属性

   DialPlot dialplot = new DialPlot();

   dialplot.setView(0.0D, 0.0D, 1.0D, 1.0D);

   dialplot.setDataset(0, hoursDataset);//设置数据源

   dialplot.setDataset(1, minitesDs);//设置分钟数据源

   //设置简单帧(钟表框颜色)

   SimpleDialFrame simpledialframe = new SimpleDialFrame();

   //设置帧背景色

   simpledialframe.setBackgroundPaint(Color.lightGray);

   //设置帧前景色

   simpledialframe.setForegroundPaint(Color.darkGray);

   dialplot.setDialFrame(simpledialframe);

   //设置钟表图形背景

   DialBackground dialbackground = new DialBackground(Color.orange);

   dialbackground.setGradientPaintTransformer(new StandardGradientPaintTransformer(

                 GradientPaintTransformType.VERTICAL));

   dialplot.setBackground(dialbackground);

   //设置钟表值范围，从0到12

   StandardDialScale standarddialscale = new StandardDialScale(0.0D,12D, 90D, -360D);

   standarddialscale.setFirstTickLabelVisible(false);

   standarddialscale.setMajorTickIncrement(1);

   //设置表刻度和数字离中心的半径

   standarddialscale.setTickRadius(0.90D);

   //设置数字离开表盘的距离

   standarddialscale.setTickLabelOffset(0.1D);

   standarddialscale.setTickLabelFont(new Font("宋体", 0, 14));

   dialplot.addScale(0, standarddialscale);

   StandardDialScale standarddialscale1 =new StandardDialScale(0.0D,60D, 90D, -360D);

   standarddialscale1.setVisible(false);

   standarddialscale1.setMajorTickIncrement(5D);

   standarddialscale1.setTickRadius(0.68D);

   standarddialscale1.setTickLabelOffset(0.15D);

   standarddialscale1.setTickLabelFont(new Font("宋体", 0, 14));

   dialplot.addScale(1, standarddialscale1);

   //设置时针的指针

   Pointerpointer = newPointer(0);

   pointer.setRadius(0.5D); //设置时针长度

   dialplot.addLayer(pointer);

   dialplot.mapDatasetToScale(1, 1)

   //设置分针的指针

   Pointerpointer1 = newPointer(1);

   pointer1.setRadius(0.7D);//设置分钟针长度

   dialplot.addLayer(pointer1);

   //设置刻度中间的圆圈的大小

   DialCap dialcap = new DialCap();

   dialcap.setRadius(0.05D);//设置圆圈长度

   dialplot.setCap(dialcap);

   //根据刻度图形建立JFreeChart对象

   JFreeChart jfreechart = new JFreeChart(dialplot);

   //设置图形的标题

   jfreechart.setTitle("钟表图示例");

   //保存图形图片

   String filename =ServletUtilities.saveChartAsPNG(jfreechart, 300,300,null, session);

   //得到图片地址

   String graphURL = request.getContextPath()

          + "/servlet/DisplayChart?filename=" + filename;

    /** 

   //显示方法二这种方法用输出流输出，不用调用后面的img两种方法都可实现图片输出

   OutputStream outs =response.getOutputStream();

   response.setContentType("image/png");

   response.reset();

   ChartUtilities.writeChartAsPNG(outs,jfreechart, 400, 300);

   outs.flush();

   outs.close();

   */

%>

<!--方法一调用<img>方法二不用它，使用方法二的时候去掉-->

<imgsrc="<%=graphURL%>"width="300"height="300"border="0"usemap="#<%= filename %>">

运行后效果如下：