Question

我正在尝试使用jsp显示jFreeChart。生成图表但无法在浏览器中查看。它在浏览器中显示一个空框架。是否还有其他配置需要执行？

JSP页面：

%@page contentType="text/html" pageEncoding="UTF-8"%>

<%@ page  import="java.awt.*" %>
<%@ page  import="java.io.*" %>
<%@ page  import="org.jfree.chart.*" %>
<%@ page  import="org.jfree.chart.axis.*" %>
<%@ page  import="org.jfree.chart.entity.*" %>
<%@ page  import="org.jfree.chart.labels.*" %>
<%@ page  import="org.jfree.chart.plot.*" %>
<%@ page  import="org.jfree.chart.renderer.category.*" %>
<%@ page  import="org.jfree.chart.urls.*" %>
<%@ page  import="org.jfree.data.category.*" %>
<%@ page  import="org.jfree.data.general.*" %>

<%
            final double[][] data = new double[][]{
                {210, 300, 320, 265, 299},
                {200, 304, 201, 201, 340}
            };

            final CategoryDataset dataset = DatasetUtilities.createCategoryDataset(
                    "Team ", "", data);

            JFreeChart chart = null;
            BarRenderer renderer = null;
            CategoryPlot plot = null;


            final CategoryAxis categoryAxis = new CategoryAxis("Match");
            final ValueAxis valueAxis = new NumberAxis("Run");
            renderer = new BarRenderer();

            plot = new CategoryPlot(dataset, categoryAxis, valueAxis, renderer);
            plot.setOrientation(PlotOrientation.VERTICAL);
            chart = new JFreeChart("Srore Bord", JFreeChart.DEFAULT_TITLE_FONT, plot, true);

            chart.setBackgroundPaint(new Color(249, 231, 236));

            Paint p1 = new GradientPaint(
                    0.0f, 0.0f, new Color(16, 89, 172), 0.0f, 0.0f, new Color(201, 201, 244));
            renderer.setSeriesPaint(1, p1);

            Paint p2 = new GradientPaint(
                    0.0f, 0.0f, new Color(255, 35, 35), 0.0f, 0.0f, new Color(255, 180, 180));
            renderer.setSeriesPaint(2, p2);

            plot.setRenderer(renderer);

            try {
                final ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());
                final File file1 = new File("D:/barchart.png");
                ChartUtilities.saveChartAsPNG(file1, chart, 600, 400, info);
            } catch (Exception e) {
                out.println(e);
            }
%>

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" >
        <!meta  http-equiv="refresh" content="1">
        <title>JSP Page</title>
    </head>

    <body>
        <IMG SRC="barchart.png" WIDTH="600" HEIGHT="400" BORDER="0" USEMAP="#chart">
    </body>
</html>

Answer 1

首先，这是一个HTML问题。

＆＃34; d：\ barchart.png＆＃34;将不是您的Web服务器加载图像的正确目录。您的IMG参考是相对于当前页面。但是您将文件放在驱动器D的根目录中。您需要将输出位置移动到Web浏览器可访问的某个位置，并调整HTML输出中的引用。

BTW。：生成图像，这可能仅适用于单个用户。对页面的并行访问可以在每次调用时删除并重新创建图像。这可能会导致并行访问时显示错误。

jFreeChart没有显示在浏览器中

1 个答案: