java.lang.UnsupportedOperationException when struts2 is running in same app.

Hello,

I have a application with thymeleaf 2.1.4.RELEASE and while i was trying to update to the 3.0.6.RELEASE version i found an issue with ognl.

org.thymeleaf.exceptions.TemplateInputException: An error happened during template parsing (template: “/WEB-INF/templates/report.html”) at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parse(AbstractMarkupTemplateParser.java:241) at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parseStandalone(AbstractMarkupTemplateParser.java:100) at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:666) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1059) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1048) at app.FormAction.execute(FormAction.java:29) at sun.reflect.GeneratedMethodAccessor1686.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java) at java.lang.reflect.Method.invoke(Method.java:498) at ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:873) at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1539) at ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:68) at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethodWithDebugInfo(XWorkMethodAccessor.java:96) at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethod(XWorkMethodAccessor.java:88) at ognl.OgnlRuntime.callMethod(OgnlRuntime.java:1615) at ognl.ASTMethod.getValueBody(ASTMethod.java:91) at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212) at ognl.SimpleNode.getValue(SimpleNode.java:258) at ognl.Ognl.getValue(Ognl.java:467) at ognl.Ognl.getValue(Ognl.java:431) at com.opensymphony.xwork2.ognl.OgnlUtil$3.execute(OgnlUtil.java:351) at com.opensymphony.xwork2.ognl.OgnlUtil.compileAndExecuteMethod(OgnlUtil.java:403) at com.opensymphony.xwork2.ognl.OgnlUtil.callMethod(OgnlUtil.java:349) at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:436) at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:291) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:252) at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:253) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:177) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:260) at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:73) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.doIntercept(ConversionErrorInterceptor.java:139) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:133) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:133) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:192) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:69) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at org.apache.struts2.interceptor.DateTextFieldInterceptor.intercept(DateTextFieldInterceptor.java:115) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:88) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:246) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:99) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:139) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:155) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:174) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at org.apache.struts2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:120) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:171) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:195) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:193) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:247) at org.apache.struts2.factory.StrutsActionProxy.execute(StrutsActionProxy.java:54) at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:564) at org.apache.struts2.dispatcher.ExecuteOperations.executeAction(ExecuteOperations.java:81) at org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:143) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:96) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:748) Caused by: org.attoparser.ParseException: Exception evaluating OGNL expression: “boss.name” (template: “report.html” - line 5, col 21) at org.attoparser.MarkupParser.parseDocument(MarkupParser.java:393) at org.attoparser.MarkupParser.parse(MarkupParser.java:257) at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parse(AbstractMarkupTemplateParser.java:230) … 95 more Caused by: org.thymeleaf.exceptions.TemplateProcessingException: Exception evaluating OGNL expression: “boss.name” (template: “report.html” - line 5, col 21) at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.evaluate(OGNLVariableExpressionEvaluator.java:191) at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.evaluate(OGNLVariableExpressionEvaluator.java:95) at org.thymeleaf.standard.expression.VariableExpression.executeVariableExpression(VariableExpression.java:165) at org.thymeleaf.standard.expression.SimpleExpression.executeSimple(SimpleExpression.java:66) at org.thymeleaf.standard.expression.Expression.execute(Expression.java:109) at org.thymeleaf.standard.expression.Expression.execute(Expression.java:138) at org.thymeleaf.standard.expression.Expression.execute(Expression.java:125) at org.thymeleaf.standard.processor.AbstractStandardExpressionAttributeTagProcessor.doProcess(AbstractStandardExpressionAttributeTagProcessor.java:82) at org.thymeleaf.processor.element.AbstractAttributeTagProcessor.doProcess(AbstractAttributeTagProcessor.java:74) at org.thymeleaf.processor.element.AbstractElementTagProcessor.process(AbstractElementTagProcessor.java:95) at org.thymeleaf.util.ProcessorConfigurationUtils$ElementTagProcessorWrapper.process(ProcessorConfigurationUtils.java:633) at org.thymeleaf.engine.ProcessorTemplateHandler.handleOpenElement(ProcessorTemplateHandler.java:1314) at org.thymeleaf.engine.TemplateHandlerAdapterMarkupHandler.handleOpenElementEnd(TemplateHandlerAdapterMarkupHandler.java:304) at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler$InlineMarkupAdapterPreProcessorHandler.handleOpenElementEnd(InlinedOutputExpressionMarkupHandler.java:278) at org.thymeleaf.standard.inline.OutputExpressionInlinePreProcessorHandler.handleOpenElementEnd(OutputExpressionInlinePreProcessorHandler.java:186) at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler.handleOpenElementEnd(InlinedOutputExpressionMarkupHandler.java:124) at org.attoparser.HtmlElement.handleOpenElementEnd(HtmlElement.java:109) at org.attoparser.HtmlMarkupHandler.handleOpenElementEnd(HtmlMarkupHandler.java:297) at org.attoparser.MarkupEventProcessorHandler.handleOpenElementEnd(MarkupEventProcessorHandler.java:402) at org.attoparser.ParsingElementMarkupUtil.parseOpenElement(ParsingElementMarkupUtil.java:159) at org.attoparser.MarkupParser.parseBuffer(MarkupParser.java:710) at org.attoparser.MarkupParser.parseDocument(MarkupParser.java:301) … 97 more Caused by: org.thymeleaf.exceptions.TemplateProcessingException: Exception evaluating OGNL expression: “boss.name” at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.evaluate(OGNLVariableExpressionEvaluator.java:191) at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.evaluate(OGNLVariableExpressionEvaluator.java:177) … 118 more Caused by: java.lang.UnsupportedOperationException at java.util.AbstractMap.put(AbstractMap.java:209) at ognl.OgnlContext.put(OgnlContext.java:579) at com.opensymphony.xwork2.ognl.accessor.ObjectAccessor.getProperty(ObjectAccessor.java:19) 2017-07-10 09:17:32,827 DEBUG [http-nio-9381-exec-8] dispatcher.DefaultDispatcherErrorHandler (DefaultDispatcherErrorHandler.java:86) - Exception occurred during processing request: org.thymeleaf.exceptions.TemplateInputException: An error happened during template parsing (template: “/WEB-INF/templates/report.html”) at ognl.OgnlRuntime.getProperty(OgnlRuntime.java:2666) at ognl.ASTProperty.getValueBody(ASTProperty.java:114) at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212) at ognl.SimpleNode.getValue(SimpleNode.java:258) at ognl.ASTChain.getValueBody(ASTChain.java:141) at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212) at ognl.SimpleNode.getValue(SimpleNode.java:258) at ognl.Ognl.getValue(Ognl.java:467) at ognl.Ognl.getValue(Ognl.java:431) at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.executeExpression(OGNLVariableExpressionEvaluator.java:316) at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.evaluate(OGNLVariableExpressionEvaluator.java:170)

VARIABLE `public class Boss {

public Boss(String name) {
    this.name = name;
}

private String name;

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

} `

TEMPLATE

<div> <h1>Thymeleaf 3 + Strut 2 example</h1> <p> Hello <span th:text="${boss.name}">Boss</span>!!! </p> </div>

In the same app i have a dependency with Struts 2.

It looks like Struts is replacing ognl.ObjectMethodAccessor with com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.

Is that an error o is it thymeleaf and Struts2 fully incompatibles?

NOTE: Without Struts2 it works as expected.

app-example.zip

[miao1007]

Hi , i met the same error, and patched by replace the singleton map with hashmap.

here is the code, but it may be only for my small project. and it will be slow and high memory cost.

public static IDialect getDialect() {
    StandardDialect dialect = new StandardDialect();
    try {
        Class.forName("com.opensymphony.xwork2.ognl.accessor.ObjectAccessor") //check has struts
    } catch (ClassNotFoundException e) {
        return dialect;
    }
    try {//replace the singleton map with hashmap
        Field field = OGNLVariableExpressionEvaluator.class.getDeclaredField("CONTEXT_VARIABLES_MAP_NOEXPOBJECTS_RESTRICTIONS");
        field.setAccessible(true);
        field.set(null, new HashMap<String, Object>())
    } catch (Exception e) {
        throw new RuntimeException("Thymleaf can't work with struts.", e)
    }
    OGNLVariableExpressionEvaluator evaluator = new OGNLVariableExpressionEvaluator(true);
    dialect.setVariableExpressionEvaluator(new IStandardVariableExpressionEvaluator() {
        Object evaluate(IExpressionContext context, IStandardVariableExpression expression, StandardExpressionExecutionContext expContext) {
            expContext = StandardExpressionExecutionContext.RESTRICTED; //false, false -> true, false
            return evaluator.evaluate(context, expression, expContext);
        }
    })
    return dialect
}

It’s just a transitional patch, i will later replace all struts with thymleaf/SpringMVC.

[danielfernandez]

I’ve had a look at the Struts 2 code, and I’m afraid I think the solution you propose would not be adequate. First, because it would be quite intrusive, adding to the Thymeleaf core a feature that would be merely a workaround –not really a fix– for a specific scenario in Struts 2; and Second, because such workaround in itself would in fact provoke an unexpected behaviour by swallowing errors. I mean, this could be OK in a very specific OGNL evaluator created for a very specific scenario… but not at the default OGNL evaluator at the Thymeleaf core.

So given that the StandardDialect does allow users to specify their own implementations of the IStandardVariableExpressionEvaluator, and therefore it would be relative easy to create an evaluator implementation equivalent to the already existing (and used by default) org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator. Then this application- or framework-specific implementation could use a context like the one you suggest to work around this behaviour in Struts 2.

Alternatively, and given this behaviour seems to only appear in Struts 2 when ObjectProxy objects are added to the context (given it is the ObjectProxyPropertyAccessor who tries to do these modifications, maybe using this kind of objects could be avoided in Struts 2 applications somehow. I don’t have much modern Struts knowledge, so I don’t know if this is even possible…

So I’m going to close this ticket as a declined feature, given there is a valid workaround for user applications/libraries (create a custom evaluator), and applying such workarounds to the Thymeleaf core would IMHO create more issues than it would solve.