JFreeChart Coldfusion中的拨号图表

问题描述

有没有人在Coldfusion上实现JFreechart拨号图的示例？

Has anyone an example of implementing a JFreechart Dial chart on Coldfusion?

感谢

推荐答案

（这可能不应该是一个单独的答案，但另一个已经很长，所以我单独发布，以保持组织和容易找到。）

如果你正在寻找什么jFreeChart调用一个MeterChart，这里是一个快速和肮脏的图表类型的例子。

In case you are looking for what jFreeChart calls a MeterChart, here is a quick and dirty example of that chart type.

MeterChart代码：

<cfscript>
    // my chart settings
    chartTitle = "My Meter Chart";
    arrowValue  = 55;
    arrowUnits  = "widgets";
    chartWidth  = 500;
    chartHeight = 500;

    // initialize meter ranges (LOW, MEDIUM, HIGH)
    // note: quick and ugly code in dire need of improvement ...
    low  = createSolidMeterInterval("Low", 0, 40, createAwtColor(0, 255, 0, 120));
    med  = createSolidMeterInterval("Med", 40, 60, createAwtColor(255, 255, 0, 120));
    high = createSolidMeterInterval("High", 60, 100, createAwtColor(255, 0, 0, 120));

    // initialize arrow value
    DefaultValueDataset = createObject("java", "org.jfree.data.general.DefaultValueDataset");
    meterPointer = DefaultValueDataset.init(arrowValue);

    //initialize plot and apply settings
    plot = createObject("java", "org.jfree.chart.plot.MeterPlot").init();
    plot.setDataset(meterPointer);
    plot.setTickLabelsVisible(true);
    plot.addInterval(low);
    plot.addInterval(med);
    plot.addInterval(high);
    plot.setUnits(arrowUnits);

    // create chart and convert it to an image
    chart = createObject("java", "org.jfree.chart.JFreeChart").init(chartTitle, plot);
    ChartUtilities = createObject("java", "org.jfree.chart.ChartUtilities");
    ChartUtilities.applyCurrentTheme(chart);

    // applyCurrentTheme seems to overwrite some settings, so we must reapply them
    Color = createObject("java", "java.awt.Color");
    plot.setBackgroundPaint(Color.GRAY);
    plot.setNeedlePaint(Color.BLACK);

    chartImage = chart.createBufferedImage(chartWidth, chartHeight);
    ImageFormat = createObject("java", "org.jfree.chart.encoders.ImageFormat");
    EncoderUtil = createObject("java", "org.jfree.chart.encoders.EncoderUtil");
    bytes = EncoderUtil.encode( chartImage, ImageFormat.PNG);
</cfscript>
<!--- display in browser --->
<cfcontent type="image/png" variable="#bytes#">

辅助功能：

<cfscript>
        // quick and ugly functions. could be improved ...
        function createSolidMeterInterval(Title, fromValue, toValue, BgColor) {
            var Range = createObject("java", "org.jfree.data.Range").init(arguments.fromValue, arguments.toValue);
            var MeterInterval = createObject("java", "org.jfree.chart.plot.MeterInterval");
            return MeterInterval.init(arguments.Title, Range   // interval from / to range
                                        , javacast("null", "") // outline color
                                        , javacast("null", "") // outline stroke
                                        , arguments.BgColor    // background color
                                    );
        }


        // using java.awt.Color is a pain due to all the javacasts ...
        function createAwtColor(r, g, b, alpha) {
            var color = createObject("java", "java.awt.Color");
            return color.init( javacast("int", arguments.r)
                                , javacast("int", arguments.g)
                                , javacast("int", arguments.b)
                                , javacast("int", arguments.alpha) // transparency
                            );
        }
</cfscript>

这篇关于JFreeChart Coldfusion中的拨号图表的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！