Struts 2 TypeConversion问题

时间：2010-05-09 04:40:41

标签： java struts2

我有一个大问题......

我有这张地图

HashMap<Long, String> examValues;

它会被文本框自动填充name="examValues[id]"虽然我明确地将元素定义为String，但它并不关心！ 我希望一切都成为一个字符串...... 结果是获得

java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String

当我尝试

时 
System.out.print(examValues.get(examValue.getExam().getId()).getClass().getName());

堆栈跟踪：

INFO: java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String
        at gr.medilab.logic.action.exams.Exams.fill_edit(Exams.java:204)
        at gr.medilab.logic.action.exams.Exams.fill(Exams.java:95)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:441)
        at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:280)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:243)
        at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:165)
        at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:252)
        at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
        at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
        at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
        at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:179)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:130)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
        at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:165)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:179)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
        at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
        at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
        at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:488)
        at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
        at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:215)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:277)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
        at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
        at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
        at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:332)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:233)
        at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
        at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
        at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
        at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
        at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
        at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
        at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
        at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
        at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
        at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
        at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
        at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
        at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
        at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309)
        at java.lang.Thread.run(Thread.java:619)

有什么想法吗？

1 个答案:

答案 0 :(得分：0)

找到解决方案...... 只有HashMap才需要Map

所以examValues声明应该是这样的：

Map<Long, String> examValues;
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