JFreechart页面图片更新问题

Question

如图,我选择时间,图表会改变,后台已经生成图片了,但是在request里还是缓存上一张的,导致页面没更新,请教下大神!

Answer 1

try {
String fileName = ServletUtilities.saveChartAsPNG(chart, 1000, 600,   request.getSession());
System.out.println(fileName);
//访问报表图片的路径
String path = request.getContextPath()+"/display.do?filename="+fileName;
request.setAttribute("path", path);
System.out.println(path);
} catch (IOException e) {
e.printStackTrace();
}后台输出
第一次的是这个
15:32:18,906 INFO  [STDOUT] jfreechart-6737838437326303125.png
15:32:18,906 INFO  [STDOUT] /PFEM/display.do?filename=jfreechart-6737838437326303125.png第二次的是这个
15:32:24,703 INFO  [STDOUT] 2013
15:32:24,890 INFO  [STDOUT] jfreechart-6634107917445325032.png
15:32:24,890 INFO  [STDOUT] /PFEM/display.do?filename=jfreechart-6634107917445325032.png页面还是之前第一个的图,没显示第二张图
<img src="${requestScope.path}" height="480" width="800">

Answer 2

String path = request.getContextPath()+"/display.do?filename="+fileName+"&t="+System.currentTimeMillis();

Answer 3

这图片不重复,就是页面不刷新显示,依然是老图15:58:36,359 INFO  [STDOUT] jfreechart-2563731017454888505.png
15:58:36,359 INFO  [STDOUT] /PFEM/display.do?filename=jfreechart-2563731017454888505.png&t=133767351635915:58:40,109 INFO  [STDOUT] 2013
15:58:40,328 INFO  [STDOUT] jfreechart-4328411123630244371.png
15:58:40,328 INFO  [STDOUT] /PFEM/display.do?filename=jfreechart-4328411123630244371.png&t=1337673520328<img src="${requestScope.path}" height="480" width="800">是这个地方出错了？能在JSP清空上次的request里的图片值吗？