W jednej z moich aplikacji testowych Struts2 utworzyłem wiele pól wyboru przy użyciu znacznika iteratora

<s:iterator value="valueAddedServicesMap">
   <s:checkbox name="reportData.valueAddedServices"  id="valueAddedServices" fieldValue="%{key}" value="%{key in reportData.valueAddedServices}"/>&nbsp;<s:property value="value"/><br/>
</s:iterator>

gdzie valueAddedServicesMap to mapa mająca pary klucz-wartość, takie jak {"1", "VAS 1"}, {"2", "VAS 2"} i mam listę <Long> w klasie akcji dla reportData.valueAddedServices

W przypadku więcej niż jednego pola wyboru działa poprawnie. Wypełnia listę w akcji wartościami powiązanymi z wit zaznaczonymi polami wyboru lub zachowuje wartość null, jeśli nie zaznaczono pola wyboru.

Wypełnia również pojedynczą wartość w przypadku tylko jednego pola wyboru do wysłania i jest zaznaczona, ale daje wyjątek, gdy wyświetlane jest tylko jedno pole wyboru i nie jest zaznaczone.

wyjątek jest jak:

[09 May 2013 10:48:45,081] [DEBUG] unable to convert value using type converter  [com.opensymphony.xwork2.conversion.impl.XWorkBasicConverter]
Unparseable number: "false" at position 0 - [unknown location]
at   com.opensymphony.xwork2.conversion.impl.NumberConverter.convertValue(NumberConverter.java:41)
at com.opensymphony.xwork2.conversion.impl.XWorkBasicConverter.doConvertToNumber(XWorkBasicConverter.java:213)
at com.opensymphony.xwork2.conversion.impl.XWorkBasicConverter.convertValue(XWorkBasicConverter.java:116)
at com.opensymphony.xwork2.conversion.impl.XWorkConverter.convertValue(XWorkConverter.java:340)
at com.opensymphony.xwork2.ognl.OgnlTypeConverterWrapper.convertValue(OgnlTypeConverterWrapper.java:39)
at com.opensymphony.xwork2.ognl.XWorkTypeConverterWrapper.convertValue(XWorkTypeConverterWrapper.java:36)
at com.opensymphony.xwork2.conversion.impl.CollectionConverter.convertValue(CollectionConverter.java:54)
at com.opensymphony.xwork2.conversion.impl.XWorkBasicConverter.doConvertToCollection(XWorkBasicConverter.java:197)
at com.opensymphony.xwork2.conversion.impl.XWorkBasicConverter.convertValue(XWorkBasicConverter.java:110)
at com.opensymphony.xwork2.conversion.impl.XWorkConverter.convertValue(XWorkConverter.java:340)
at com.opensymphony.xwork2.ognl.OgnlTypeConverterWrapper.convertValue(OgnlTypeConverterWrapper.java:39)
at ognl.OgnlRuntime.getConvertedType(OgnlRuntime.java:1064)
at ognl.OgnlRuntime.getConvertedTypes(OgnlRuntime.java:1081)
at ognl.OgnlRuntime.getConvertedMethodAndArgs(OgnlRuntime.java:1107)
at ognl.OgnlRuntime.getAppropriateMethod(OgnlRuntime.java:1193)
at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1207)
at ognl.OgnlRuntime.setMethodValue(OgnlRuntime.java:1478)
at ognl.ObjectPropertyAccessor.setPossibleProperty(ObjectPropertyAccessor.java:85)
at ognl.ObjectPropertyAccessor.setProperty(ObjectPropertyAccessor.java:162)
at com.opensymphony.xwork2.ognl.accessor.ObjectAccessor.setProperty(ObjectAccessor.java:27)
at ognl.OgnlRuntime.setProperty(OgnlRuntime.java:2315)
at ognl.ASTProperty.setValueBody(ASTProperty.java:127)
at ognl.SimpleNode.evaluateSetValueBody(SimpleNode.java:220)
at ognl.SimpleNode.setValue(SimpleNode.java:301)
at ognl.ASTChain.setValueBody(ASTChain.java:227)
at ognl.SimpleNode.evaluateSetValueBody(SimpleNode.java:220)
at ognl.SimpleNode.setValue(SimpleNode.java:301)
at ognl.Ognl.setValue(Ognl.java:737)
at com.opensymphony.xwork2.ognl.OgnlUtil.setValue(OgnlUtil.java:217)
at com.opensymphony.xwork2.ognl.OgnlValueStack.trySetValue(OgnlValueStack.java:186)
at com.opensymphony.xwork2.ognl.OgnlValueStack.setValue(OgnlValueStack.java:173)
at com.opensymphony.xwork2.ognl.OgnlValueStack.setParameter(OgnlValueStack.java:151)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.setParameters(ParametersInterceptor.java:317)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:228)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:236)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:90)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:192)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.test.app.web.interceptor.AuthenticationInterceptor.intercept(AuthenticationInterceptor.java:48)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:511)
at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:432)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)

wszelka pomoc w tej sprawie byłaby bardzo mile widziana