REST API returns HTML errors (by Tomcat)

Hey,

Exceptions are propagated from process instance execution up to the tomcat container,

This behaviour returns <html> tags back to the caller, which is not API/REST friendly,

Is there any way to return a JSON formatted errors out of Camunda’s REST API ?

Thanks,

Asaf.

I’m having the exact same question, but I can’t find this anywhere. I’ve tried adding the Accept: application/json header, but the result is still the same.

Which API are you calling?

Expected errors should be returning Json. But there are not uncaught errors I have found that will return raw tomcat HTML.

What is your specific error.

I’m just starting a process, but there were some parameters missing that I didn’t pass. Then, this caused an input parameter to be a wrong json.

I’m seeing this with other exceptions also. When something goes wrong during the process, and it’s not async, i will get back an html error.

(the additional escaping is due to the dumping of the exception)

\<!DOCTYPE html>\<html>\<head>\<title>Apache Tomcat/8.0.47 - Error report\</title>\<style type="text/css">H1 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:22px;} H2 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:16px;} H3 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:14px;} BODY {font-family:Tahoma,Arial,sans-serif;color:black;background-color:white;} B {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;} P {font-family:Tahoma,Arial,sans-serif;background:white;color:black;font-size:12px;}A {color : black;}A.name {color : black;}.line {height: 1px; background-color: #525D76; border: none;}\</style> \</head>\<body>\<h1>HTTP Status 500 - java.lang.IllegalArgumentException: Message is not a valid json\</h1>\<div class="line">\</div>\<p>\<b>type\</b> Exception report\</p>\<p>\<b>message\</b> \<u>java.lang.IllegalArgumentException: Message is not a valid json\</u>\</p>\<p>\<b>description\</b> \<u>The server encountered an internal error that prevented it from fulfilling this request.\</u>\</p>\<p>\<b>exception\</b>\</p>\<pre>org.jboss.resteasy.spi.UnhandledException: java.lang.IllegalArgumentException: Message is not a valid json
        org.jboss.resteasy.core.SynchronousDispatcher.handleApplicationException(SynchronousDispatcher.java:365)
        org.jboss.resteasy.core.SynchronousDispatcher.handleException(SynchronousDispatcher.java:233)
        org.jboss.resteasy.core.SynchronousDispatcher.handleInvokerException(SynchronousDispatcher.java:209)
        org.jboss.resteasy.core.SynchronousDispatcher.getResponse(SynchronousDispatcher.java:557)
        org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:524)
        org.jboss.resteasy.core.SynchronousDispatcher.invokePropagateNotFound(SynchronousDispatcher.java:169)
        org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:212)
        org.jboss.resteasy.plugins.server.servlet.FilterDispatcher.doFilter(FilterDispatcher.java:59)
        org.camunda.bpm.engine.rest.security.auth.ProcessEngineAuthenticationFilter.doFilter(ProcessEngineAuthenticationFilter.java:148)
        org.camunda.bpm.engine.rest.filter.CacheControlFilter.doFilter(CacheControlFilter.java:41)
        org.camunda.bpm.engine.rest.filter.EmptyBodyFilter.doFilter(EmptyBodyFilter.java:95)
\</pre>\<p>\<b>root cause\</b>\</p>\<pre>java.lang.IllegalArgumentException: Message is not a valid json
        org.camunda.bpm.destiny.QueuePublish.getMessage(QueuePublish.java:127)
        org.camunda.bpm.destiny.QueuePublish.execute(QueuePublish.java:70)
        org.camunda.bpm.engine.impl.bpmn.delegate.JavaDelegateInvocation.invoke(JavaDelegateInvocation.java:36)
        org.camunda.bpm.engine.impl.delegate.DelegateInvocation.proceed(DelegateInvocation.java:54)
        org.camunda.bpm.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocationInContext(DefaultDelegateInterceptor.java:87)
        org.camunda.bpm.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocation(DefaultDelegateInterceptor.java:59)
        org.camunda.bpm.engine.impl.bpmn.behavior.ServiceTaskJavaDelegateActivityBehavior.execute(ServiceTaskJavaDelegateActivityBehavior.java:50)
        org.camunda.bpm.engine.impl.bpmn.behavior.ServiceTaskJavaDelegateActivityBehavior.performExecution(ServiceTaskJavaDelegateActivityBehavior.java:41)
        org.camunda.bpm.engine.impl.bpmn.behavior.TaskActivityBehavior.execute(TaskActivityBehavior.java:65)
        org.camunda.bpm.engine.impl.bpmn.behavior.ClassDelegateActivityBehavior$1.call(ClassDelegateActivityBehavior.java:65)
        org.camunda.bpm.engine.impl.bpmn.behavior.ClassDelegateActivityBehavior$1.call(ClassDelegateActivityBehavior.java:62)
        org.camunda.bpm.engine.impl.bpmn.behavior.AbstractBpmnActivityBehavior.executeWithErrorPropagation(AbstractBpmnActivityBehavior.java:108)
        org.camunda.bpm.engine.impl.bpmn.behavior.ClassDelegateActivityBehavior.execute(ClassDelegateActivityBehavior.java:62)
        org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute$2.callback(PvmAtomicOperationActivityExecute.java:57)
        org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute$2.callback(PvmAtomicOperationActivityExecute.java:46)
        org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.continueIfExecutionDoesNotAffectNextOperation(PvmExecutionImpl.java:1958)
        org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute.execute(PvmAtomicOperationActivityExecute.java:38)
        org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute.execute(PvmAtomicOperationActivityExecute.java:27)
        org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:91)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:125)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:104)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:79)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:618)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:594)
        org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl$5.callback(PvmExecutionImpl.java:1897)
        org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl$5.callback(PvmExecutionImpl.java:1894)
        org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.continueExecutionIfNotCanceled(PvmExecutionImpl.java:1964)
        org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.dispatchDelayedEventsAndPerformOperation(PvmExecutionImpl.java:1913)
        org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.dispatchDelayedEventsAndPerformOperation(PvmExecutionImpl.java:1894)
        org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityStart.eventNotificationsCompleted(PvmAtomicOperationActivityStart.java:38)
        org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityStart.eventNotificationsCompleted(PvmAtomicOperationActivityStart.java:26)
        org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:65)
        org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:91)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:125)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:104)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:79)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:69)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:629)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:604)
        org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:58)
        org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:91)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:125)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:104)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:79)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:69)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:629)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:604)
        org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:58)
        org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:91)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:125)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:104)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:79)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:69)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:629)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:604)
        org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:58)
        org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:91)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:125)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:104)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:79)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:618)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:594)
        org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityStartCreateScope.scopeCreated(PvmAtomicOperationActivityStartCreateScope.java:39)
        org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationCreateScope.execute(PvmAtomicOperationCreateScope.java:50)
        org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationCreateScope.execute(PvmAtomicOperationCreateScope.java:24)
        org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:91)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:125)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:112)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext$1.call(CommandInvocationContext.java:95)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext$1.call(CommandInvocationContext.java:93)
        org.camunda.bpm.engine.impl.context.ProcessApplicationClassloaderInterceptor.call(ProcessApplicationClassloaderInterceptor.java:44)
        org.camunda.bpm.application.AbstractProcessApplication.execute(AbstractProcessApplication.java:114)
        org.camunda.bpm.application.AbstractProcessApplication.execute(AbstractProcessApplication.java:125)
        org.camunda.bpm.engine.impl.context.Context.executeWithinProcessApplication(Context.java:192)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:93)
        org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:79)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:618)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:594)
        org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.start(PvmExecutionImpl.java:237)
        org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.start(ExecutionEntity.java:431)
        org.camunda.bpm.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:59)
        org.camunda.bpm.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:31)
        org.camunda.bpm.engine.impl.interceptor.CommandExecutorImpl.execute(CommandExecutorImpl.java:24)
        org.camunda.bpm.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:104)
        org.camunda.bpm.engine.impl.interceptor.ProcessApplicationContextInterceptor.execute(ProcessApplicationContextInterceptor.java:66)
        org.camunda.bpm.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:30)
        org.camunda.bpm.engine.impl.ProcessInstantiationBuilderImpl.executeWithVariablesInReturn(ProcessInstantiationBuilderImpl.java:162)
        org.camunda.bpm.engine.rest.sub.repository.impl.ProcessDefinitionResourceImpl.startProcessInstanceAtActivities(ProcessDefinitionResourceImpl.java:169)
        org.camunda.bpm.engine.rest.sub.repository.impl.ProcessDefinitionResourceImpl.startProcessInstance(ProcessDefinitionResourceImpl.java:119)
        sun.reflect.GeneratedMethodAccessor337.invoke(Unknown Source)
        sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        java.lang.reflect.Method.invoke(Method.java:498)
        org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:167)
        org.jboss.resteasy.core.ResourceMethod.invokeOnTarget(ResourceMethod.java:257)
        org.jboss.resteasy.core.ResourceMethod.invoke(ResourceMethod.java:222)
        org.jboss.resteasy.core.ResourceLocator.invokeOnTargetObject(ResourceLocator.java:159)
        org.jboss.resteasy.core.ResourceLocator.invoke(ResourceLocator.java:107)
        org.jboss.resteasy.core.ResourceLocator.invokeOnTargetObject(ResourceLocator.java:154)
        org.jboss.resteasy.core.ResourceLocator.invoke(ResourceLocator.java:92)
        org.jboss.resteasy.core.SynchronousDispatcher.getResponse(SynchronousDispatcher.java:542)
        org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:524)
        org.jboss.resteasy.core.SynchronousDispatcher.invokePropagateNotFound(SynchronousDispatcher.java:169)
        org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:212)
        org.jboss.resteasy.plugins.server.servlet.FilterDispatcher.doFilter(FilterDispatcher.java:59)
        org.camunda.bpm.engine.rest.security.auth.ProcessEngineAuthenticationFilter.doFilter(ProcessEngineAuthenticationFilter.java:148)
        org.camunda.bpm.engine.rest.filter.CacheControlFilter.doFilter(CacheControlFilter.java:41)
        org.camunda.bpm.engine.rest.filter.EmptyBodyFilter.doFilter(EmptyBodyFilter.java:95)
\</pre>\<p>\<b>note\</b> \<u>The full stack trace of the root cause is available in the Apache Tomcat/8.0.47 logs.\</u>\</p>\<hr class="line">\<h3>Apache Tomcat/8.0.47\</h3>\</body>\</html>