您当前的位置: 按照网上的说法改了saveChartAsPNG()方法,写了个BarChart类，内容如下
- Java code
public class BarChart extends ServletUtilities {
protected static void createTempDir()
{
String tempDirName = "E:/myworkspace/st2/WebRoot/upload1";
if (tempDirName == null)
{
throw new RuntimeException("Temporary directory system property " + "(java.io.tmpdir) is null.");
}
// create the temporary directory if it doesn't exist
File tempDir = new File(tempDirName);
if (!tempDir.exists())
{
tempDir.mkdirs();
}
}
public static String saveChartAsPNG(JFreeChart chart, int width, int height,
ChartRenderingInfo info, HttpSession session) throws IOException
{
if (chart == null)
{
throw new IllegalArgumentException("Null 'chart' argument.");
}
createTempDir();
String prefix = ServletUtilities.getTempFilePrefix();
if (session == null)
{
prefix = ServletUtilities.getTempOneTimeFilePrefix();
}
File tempFile = File.createTempFile(prefix, ".png", new File("E:/myworkspace/st2/WebRoot/upload1"));
ChartUtilities.saveChartAsPNG(tempFile, chart, width, height, info);
if (session != null)
{
ServletUtilities.registerChartForDeletion(tempFile, session);
}
System.out.println("tempFile.getName()=" + tempFile.getName());
return tempFile.getName();
}
}
随后在jsp页面中这样写代码的
- Java code
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="org.jfree.data.general.DefaultPieDataset"%>
<%@ page import="org.jfree.chart.ChartFactory"%>
<%@ page
import="org.jfree.chart.JFreeChart,org.jfree.chart.servlet.ServletUtilities,com.test.jfreechart.BarChart"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<s:form namespace="/">
<%
DefaultPieDataset dpd = new DefaultPieDataset();
dpd.setValue("管理人员", 25);
dpd.setValue("市场人员", 25);
dpd.setValue("开发人员", 45);
dpd.setValue("其他人员", 10);
JFreeChart chart = ChartFactory.createPieChart("某公司组织结构图", dpd,
true, false, false);
String fileName = "";
fileName = BarChart
.saveChartAsPNG(chart, 800, 600, session);
System.out.println("fileName=" + fileName);
String url = request.getContextPath() + "/DisplayChart?filename="
+ fileName;
System.out.println("url =" + url);
%>
<img src="<%=url%>" width="500" height="300">
</s:form>
</body>
</html>
运行结果是
它还是在Tomcat的temp目录下生成图片，感觉我写的类都没用一样。而且还报了警告，内容是
警告: No configuration found for the specified action: '/jfreeChart2.jsp' in namespace: '/'. Form action defaulting to 'action' attribute's literal value.