JfreeCHart 异常：Chart image not found

1. http://bbs.justep.com/thread-54775-1-1.html
2. java.lang.IllegalArgumentException: Width (0) and height (0) cannot be <= 0
3.         at java.awt.image.DirectColorModel.createCompatibleWritableRaster(DirectColorModel.java:999)
4.         at java.awt.image.BufferedImage.<init>(BufferedImage.java:323)
5.         at org.jfree.chart.JFreeChart.createBufferedImage(JFreeChart.java:1394)
6.         at org.jfree.chart.JFreeChart.createBufferedImage(JFreeChart.java:1376)
7.         at org.jfree.chart.ChartUtilities.writeChartAsPNG(ChartUtilities.java:169)
8.         at org.jfree.chart.ChartUtilities.saveChartAsPNG(ChartUtilities.java:305)
9.         at org.jfree.chart.servlet.ServletUtilities.saveChartAsPNG(ServletUtilities.java:187)
10.         at com.justep.chart.JustepChartHelper.executeChart(Unknown Source)
11.         at com.justep.report.core.XReportChartHelper.executeChart(Unknown Source)
12.         at com.justep.report.core.XReportHelper.a(Unknown Source)
13.         at com.justep.report.core.XReportHelper.executeXReport(Unknown Source)
14.         at com.justep.report.controller.ReportController.execute(Unknown Source)
15.         at com.justep.report.controller.GenericControllerChain.execute(Unknown Source)
16.         at com.justep.report.controller.DataController.execute(Unknown Source)
17.         at com.justep.report.controller.GenericControllerChain.execute(Unknown Source)
18.         at com.justep.report.controller.InitController.execute(Unknown Source)
19.         at com.justep.report.controller.GenericControllerChain.execute(Unknown Source)
20.         at com.justep.report.Servlet.a(Unknown Source)
21.         at com.justep.report.Servlet.doPost(Unknown Source)
22.         at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
23.         at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
24.         at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
25.         at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
26.         at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
27.         at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
28.         at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
29.         at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
30.         at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
31.         at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
32.         at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
33.         at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
34.         at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
35.         at java.lang.Thread.run(Thread.java:595)
36. 2013-9-3 11:53:35 org.apache.catalina.core.StandardWrapperValve invoke
37. 严重: Servlet.service() for servlet display-chart-servlet threw exception
38. javax.servlet.ServletException: Chart image not found
39.         at org.jfree.chart.servlet.DisplayChart.service(DisplayChart.java:149)
40.         at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
41.         at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
42.         at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
43.         at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
44.         at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
45.         at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
46.         at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
47.         at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
48.         at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
49.         at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
50.         at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
51.         at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
52.         at java.lang.Thread.run(Thread.java:595)
53. java.lang.UnsupportedOperationException: Method failed: HTTP/1.1 500 Internal Server Error
54.         at com.justep.res.proxy.ResourceProxy.a(Unknown Source)
55.         at com.justep.res.proxy.ResourceProxy.doPost(Unknown Source)
56.         at com.justep.res.proxy.ResourceProxy.doGet(Unknown Source)
57.         at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
58.         at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
59.         at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
60.         at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
61.         at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
62.         at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
63.         at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
64.         at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
65.         at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
66.         at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
67.         at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
68.         at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
69.         at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
70.         at java.lang.Thread.run(Thread.java:595)

原因主要有以下几点:
1.chart组件的宽和高设置了100%.解决办法是设置成固定的宽和高.
2.chart组建的auto-load设置了true.改成false就好了.
3.当页面有两个报表以上时,刷新一个即可.