java 如何在jsp页面中显示饼图？
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How can i display pie chart in jsp page?
提问by anoop
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%@ page import="java.awt.*"%>
<%@ page import="java.io.*"%>
<%@ page import="org.jfree.chart.*"%>
<%@ page import="org.jfree.chart.entity.*"%>
<%@ page import="org.jfree.data.general.*"%>
<%
DefaultPieDataset pieDataset = new DefaultPieDataset();
pieDataset.setValue("JavaWorld", new Integer(75));
pieDataset.setValue("Other", new Integer(25));
JFreeChart chart = ChartFactory.createPieChart("Sample Pie Chart",pieDataset,true,true,false);
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Pie Chart</title>
</head>
<body>
<IMG SRC="piechart.png" WIDTH="600" HEIGHT="400" BORDER="0"
USEMAP="#chart">
</body>
</html>
Output for this is a blank screen, It not thrown any exception..
这个输出是一个空白屏幕，它没有抛出任何异常..
How can i display pie chart in this page?
如何在此页面中显示饼图？
Thanks in advance.
提前致谢。
回答by Hemant Metalia
after creating the chart save the chart as follow:
创建图表后保存图表如下：
ChartUtilities.saveChartAsJPEG(new File(path/piechart.png"),chart,400, 300);
and then
接着
use
利用
<IMG SRC=path/"piechart.png" WIDTH="600" HEIGHT="400" BORDER="0"
USEMAP="#chart">
**Other way is as discussed in ** How to display line graph using JFreeChart in jsp?
**其他方式如**如何在jsp中使用JFreeChart显示折线图？
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("image/png");
ServletOutputStream os = response.getOutputStream();
ImageIO.write(getChart(request), "png", os);
os.close();
}
private RenderedImage getChart(HttpServletRequest request) {
String chart = request.getParameter("chart");
// also you can process other parameters like width or height here
if (chart.equals("myDesiredChart1")) {
JFreeChart chart = [create your chart here];
return chart.createBufferedImage(width, height)
}
and display as
并显示为
<img src="/ChartDrawerServlet?chart=myDesiredChart1&width=..and other processed parameters" ..>
see the answer of Martin Lazar here
在这里看到 Martin Lazar 的回答
回答by anoop
Finally i got the answer....
最后我得到了答案......
.....In servlet....
.....在servlet中....
public void getPieChart() {
DefaultPieDataset pieDataset = new DefaultPieDataset();
pieDataset.setValue("JavaWorld", new Integer(75));
pieDataset.setValue("Other", new Integer(25));
JFreeChart chart = ChartFactory.createPieChart("Discounts Used by Category ", data, true, true, false);
//chart.setBackgroundPaint(new Color(222, 222, 255));
final PiePlot plot = (PiePlot) chart.getPlot();
plot.setBackgroundPaint(Color.white);
plot.setCircular(true);
try {
final ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());
final File file1 = new File(getServletContext().getRealPath(".") + "/images/charts/piechart.png");
ChartUtilities.saveChartAsPNG(file1, chart, 600, 400, info);
} catch (Exception e) {
System.out.println(e);
}
}
.....in html page......
.....在 html 页面中......
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Pie Chart</title>
</head>
<body>
<IMG SRC="piechart.png" WIDTH="600" HEIGHT="400" BORDER="0"
USEMAP="#chart">
</body>
</html>
............................................................................
………………………………………………………………………………………………………………………………………………………… ......................................
......................Or using only jsp page........
......................或者只使用jsp页面......
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%@ page import="java.awt.*"%>
<%@ page import="java.io.*"%>
<%@ page import="org.jfree.chart.*"%>
<%@ page import="org.jfree.chart.entity.*"%>
<%@ page import="org.jfree.data.general.*"%>
<%
DefaultPieDataset pieDataset = new DefaultPieDataset();
pieDataset.setValue("JavaWorld", new Integer(75));
pieDataset.setValue("Other", new Integer(25));
JFreeChart chart = ChartFactory.createPieChart("Discounts Used by Category ", data, true, true, false);
//chart.setBackgroundPaint(new Color(222, 222, 255));
final PiePlot plot = (PiePlot) chart.getPlot();
plot.setBackgroundPaint(Color.white);
plot.setCircular(true);
try {
final ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());
final File file1 = new File(getServletContext().getRealPath(".") + "/images/charts/piechart.png");
ChartUtilities.saveChartAsPNG(file1, chart, 600, 400, info);
} catch (Exception e) {
System.out.println(e);
}
}
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Pie Chart</title>
</head>
<body>
<IMG SRC="piechart.png" WIDTH="600" HEIGHT="400" BORDER="0"
USEMAP="#chart">
</body>
</html>
