ASDF1982

public  static String generatePieChart(DefaultPieDataset dataset,String title,int width,int height,HttpSession session, PrintWriter pw) {    
  
String filename = null;    
 try {    
 if (session != null)    
 {    
ChartDeleter deleter = (ChartDeleter)session.getAttribute("JFreeChart_Deleter");    
 session.removeAttribute("JFreeChart_Deleter");    
 session.setAttribute("JFreeChart_Deleter", deleter);    
}    
JFreeChart chart = ChartFactory.createPieChart3D(    
title,  // chart title    
dataset, // data    
true,  // include legend    
true,    
false );    
//  Write the chart image to the temporary directory    
ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());    
//If the last parameter is null, the chart is a "one time"-chart and will be deleted after the first serving.    
//If the last parameter is a session object, the chart remains until session time out.    
filename = ServletUtilities.saveChartAsPNG(chart, width, height, info, session);    
//  Write the image map to the PrintWriter    
 ChartUtilities.writeImageMap(pw, filename, info,true);    
 pw.flush();    
} catch (Exception e) {    
 System.out.println("Exception - " + e.toString());    
 e.printStackTrace(System.out);    
 filename = "picture_error.png"; }    
return filename;    
}    
}   

DefaultPieDataset piedataset=(DefaultPieDataset)request.getAttribute("piedataset"); 
String p = ChartUtil.generatePieChart(piedataset," 项目收支线图",500,300,null, new PrintWriter(out));    
String p1 = request.getContextPath() + "/servlet/DisplayChart?filename=" + p;


<td><img src="<%= p1 %>" width=500 height=300 border=0 usemap="#<%= p %>"></td>  

<servlet>  
  <servlet-name>DisplayChart</servlet-name>  
  <servlet-class>org.jfree.chart.servlet.DisplayChart</servlet-class>  
</servlet>  
<servlet-mapping>  
    <servlet-name>DisplayChart</servlet-name>  
    <url-pattern>/servlet/DisplayChart</url-pattern>  
</servlet-mapping>