JSON 报错java.lang.reflect.InvocationTargetException

03:38:46,022 ERROR runtime:96 - Template processing error: “Method public java.lang.String org.apache.commons.lang.exception.NestableRuntimeException.getMessage(int) threw an exception when invoked on net.sf.json.JSONException: java.lang.reflect.InvocationTargetException”

Method public java.lang.String org.apache.commons.lang.exception.NestableRuntimeException.getMessage(int) threw an exception when invoked on net.sf.json.JSONException: java.lang.reflect.InvocationTargetException
The problematic instruction:

==> ${msg[0]} [on line 68, column 29 in org/apache/struts2/dispatcher/error.ftl]

Java backtrace for programmers:

freemarker.template.TemplateModelException: Method public java.lang.String org.apache.commons.lang.exception.NestableRuntimeException.getMessage(int) threw an exception when invoked on net.sf.json.JSONException: java.lang.reflect.InvocationTargetException
at freemarker.ext.beans.SimpleMethodModel.exec(SimpleMethodModel.java:130)
at freemarker.ext.beans.SimpleMethodModel.get(SimpleMethodModel.java:138)
at freemarker.core.DynamicKeyName.dealWithNumericalKey(DynamicKeyName.java:111)
at freemarker.core.DynamicKeyName._getAsTemplateModel(DynamicKeyName.java:90)
at freemarker.core.Expression.getAsTemplateModel(Expression.java:89)
at freemarker.core.Expression.getStringValue(Expression.java:93)
at freemarker.core.DollarVariable.accept(DollarVariable.java:76)
at freemarker.core.Environment.visit(Environment.java:221)
at freemarker.core.MixedContent.accept(MixedContent.java:92)
at freemarker.core.Environment.visit(Environment.java:221)
at freemarker.core.IfBlock.accept(IfBlock.java:82)
at freemarker.core.Environment.visit(Environment.java:221)
at freemarker.core.IteratorBlockContext.runLoop(IteratorBlock.java:179)
at freemarker.core.Environment.visit(Environment.java:428)
at freemarker.core.IteratorBlock.accept(IteratorBlock.java:102)
at freemarker.core.Environment.visit(Environment.java:221)
at freemarker.core.MixedContent.accept(MixedContent.java:92)
at freemarker.core.Environment.visit(Environment.java:221)
at freemarker.core.IfBlock.accept(IfBlock.java:82)
at freemarker.core.Environment.visit(Environment.java:221)
at freemarker.core.MixedContent.accept(MixedContent.java:92)
at freemarker.core.Environment.visit(Environment.java:221)
at freemarker.core.Environment.process(Environment.java:199)
at freemarker.template.Template.process(Template.java:259)
at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:875)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:586)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:94)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:492)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1152)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684)atorg.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1539)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1495)atjava.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)atjava.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at freemarker.ext.beans.SimpleMemberModel.unwrapArguments(SimpleMemberModel.java:86)
at freemarker.ext.beans.SimpleMethodModel.exec(SimpleMethodModel.java:106)
… 45 more
将对象输出为json格式有问题
使用JsonConfig，jc.setExcludes(args);解决