利用jfreechart实现温度计监控设备运行

 

/**

**QQ:252574345

**MSN:[email protected]

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最近因为业务需要,希望对一个设备的温度进行监控,为了直观描述其温度变化,所以利用 JFreeChart做了下面的图形

本工程例环境:

Jfreechart1.0.6

eclipse 3.2

tomcat 5.0.28

 

 

效果如图:

 

 

代码如下:(付后下载)

 

tep.jsp

 

<%@ page contentType="text/html;charset=GBK"%>
<%@ page import="java.awt.Color,
                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.*,
                org.jfree.chart.plot.CategoryPlot,
                org.jfree.chart.axis.CategoryAxis,
                org.jfree.chart.axis.ValueAxis,
                org.jfree.chart.renderer.category.BarRenderer3D,
                org.jfree.chart.urls.StandardCategoryURLGenerator,
                org.jfree.chart.*,
                org.jfree.chart.entity.*,
                org.jfree.chart.labels.*,
                org.jfree.chart.axis.CategoryLabelPositions,
                java.awt.Font,
                java.awt.GradientPaint,
                org.jfree.ui.TextAnchor,
                org.jfree.chart.axis.NumberAxis,
                org.jfree.chart.axis.NumberTickUnit,
                java.text.DecimalFormat,
                org.jfree.chart.plot.ThermometerPlot,
                org.jfree.data.general.DefaultValueDataset             
                "%>
<%

         DefaultValueDataset defaultvaluedataset = new DefaultValueDataset(37.2);
         ThermometerPlot thermometerplot = new ThermometerPlot(defaultvaluedataset);
         JFreeChart chart = new JFreeChart("设备取水温度采样", thermometerplot);
         chart.setBackgroundPaint(Color.white);
      
         String filename = ServletUtilities.saveChartAsPNG(chart, 400, 300, session);
         //调用DisplayChart（配置在webxml中），生成图形
         String graphURL = request.getContextPath() + "/DisplayChart?filename=" + filename;
      
      
       
%>

<table width="100%">
    <tr>
        <td align="center">
            <!-- 生成图形 -->
            <img src="<%= graphURL %>" width=400 height=300 border=0  alt="">
        </td>
    </tr>
</table>