struts2+jfreechart报错

各位高人，帮忙看看是什么原因？2011-12-05 02:03:35,903 [INFO] [com.opensymphony.xwork2.validator.ActionValidatorManagerFactory.<clinit>(ActionValidatorManagerFactory.java:29)] - Detected AnnotationActionValidatorManager, initializing it...
2011-12-05 02:03:43,996 [ERROR] [com.opensymphony.xwork2.DefaultActionInvocation.createResult(DefaultActionInvocation.java:198)] - There was an exception while instantiating the result of type org.apache.struts2.dispatcher.ChartResult
Caught OgnlException while setting property 'chart' on type 'org.apache.struts2.dispatcher.ChartResult'. - Class: ognl.OgnlRuntime
File: OgnlRuntime.java
Method: callAppropriateMethod
Line: 810 - ognl/OgnlRuntime.java:810:-1
at com.opensymphony.xwork2.util.OgnlUtil.internalSetProperty(OgnlUtil.java:367)
at com.opensymphony.xwork2.util.OgnlUtil.setProperties(OgnlUtil.java:76)
at com.opensymphony.xwork2.ObjectFactory.buildResult(ObjectFactory.java:222)
at com.opensymphony.xwork2.DefaultActionInvocation.createResult(DefaultActionInvocation.java:195)
at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:342)
。。【此处略去一部分，太长了】
at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:87)
at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:187)
at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:265)
at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:273)
at com.caucho.server.port.TcpConnection.run(TcpConnection.java:682)
at com.caucho.util.ThreadPool$Item.runTasks(ThreadPool.java:743)
at com.caucho.util.ThreadPool$Item.run(ThreadPool.java:662)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NoSuchMethodException: setChart(java.lang.String)
at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:810)
at ognl.OgnlRuntime.setMethodValue(OgnlRuntime.java:964)
at ognl.ObjectPropertyAccessor.setPossibleProperty(ObjectPropertyAccessor.java:75)
at ognl.ObjectPropertyAccessor.setProperty(ObjectPropertyAccessor.java:131)
at com.opensymphony.xwork2.util.OgnlValueStack$ObjectAccessor.setProperty(OgnlValueStack.java:68)
at ognl.OgnlRuntime.setProperty(OgnlRuntime.java:1656)
at ognl.ASTProperty.setValueBody(ASTProperty.java:101)
at ognl.SimpleNode.evaluateSetValueBody(SimpleNode.java:177)
at ognl.SimpleNode.setValue(SimpleNode.java:246)
at ognl.Ognl.setValue(Ognl.java:476)
at com.opensymphony.xwork2.util.OgnlUtil.setValue(OgnlUtil.java:186)
at com.opensymphony.xwork2.util.OgnlUtil.internalSetProperty(OgnlUtil.java:360)