json数据传到前台报错：org.apache.struts2.json.JSONException

错误描述：json数据无法从action传到前台 ，报以下错误：  

错误信息：

HTTP Status 500 - org.apache.struts2.json.JSONException: 
org.apache.struts2.json.JSONException: 
org.apache.struts2.json.JSONException: 
org.apache.struts2.json.JSONException: 
org.apache.struts2.json.JSONException: 
org.apache.struts2.json.JSONException: 
org.apache.struts2.json.JSONException: java.lang.IllegalAccessException:
 Class org.apache.struts2.json.JSONWriter can not access a member of 
class 
org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl$EntityInstrumentationMetadataImpl
 with modifiers "public"


exception 
org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.IllegalAccessException: Class org.apache.struts2.json.JSONWriter can not access a member of class org.hibernate.bytecode.internal.javassist.BytecodeProviderImpl$EntityInstrumentationMetadataImpl with modifiers "public"
	org.apache.struts2.json.JSONWriter.bean(JSONWriter.java:230)
	org.apache.struts2.json.JSONWriter.process(JSONWriter.java:160)
	org.apache.struts2.json.JSONWriter.value(JSONWriter.java:126)
	org.apache.struts2.json.JSONWriter.write(JSONWriter.java:94)
	org.apache.struts2.json.JSONUtil.serialize(JSONUtil.java:115)
	org.apache.struts2.json.JSONResult.createJSONString(JSONResult.java:200)
	org.apache.struts2.json.JSONResult.execute(JSONResult.java:172)
	com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:371)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:275)
	org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)
	org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:161)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
	org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
	org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:563)
	org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
	org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)

错误原因：配置文件写错，少写了<param name="root">jsonData</param>，导致前台接收不到东西，弱智错误

<result name="success" type="json">

<param name="root">jsonData</param>

</result>