[WW-3609] Struts problem report not working properly (Freemarker template error in error.ftl at line 68 in conjunction with special exception types)

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.2.1
• Fix Version/s: 2.3.7

Environment

Sun JDK 1.6

• Assignee: Lukasz Lenart
• Reporter: Markus Kreusch
• Created: 20/Apr/11 12:33
• Updated: 06/Sep/13 06:24
• Resolved: 11/Oct/12 12:58

Description

I've a struts 2 application where the instantiation of an action leads to a org.hibernate.exception.GenericJDBCException. This exception is "expected" (during development) and because development mode is enabled it should lead to a "Struts Problem Report" page showing the exception details.

The problem report page does not contain the full information of the exception but a big yellow box titled "FreeMarker template error!" appears. Details inside the box are:

Method public java.lang.String org.hibernate.exception.NestableRuntimeException.getMessage(int) threw an exception when invoked on org.hibernate.exception.GenericJDBCException: could not execute query
The problematic instruction:
----------
==> ${msg[0]} [on line 68, column 29 in org/apache/struts2/dispatcher/error.ftl]

freemarker.template.TemplateModelException: Method public java.lang.String org.hibernate.exception.NestableRuntimeException.getMessage(int) threw an exception when invoked on org.hibernate.exception.GenericJDBCException: could not execute query
at freemarker.ext.beans.SimpleMethodModel.exec(SimpleMethodModel.java:130)
.... [part of the stack trace ommited]
Caused by: java.lang.NullPointerException
at freemarker.ext.beans.SimpleMemberModel.unwrapArguments(SimpleMemberModel.java:85)
at freemarker.ext.beans.SimpleMethodModel.exec(SimpleMethodModel.java:106)
... 47 more

I could determine the exact position of the NullPointerException by debugging the code. I'm not sure why but the class SimpleMemberModel gets instantiated
with the method org.hibernate.exception.NestableRuntimeException.getMessage(int) and null for the argTypes array. This leads to the NullPointerException at line 85 (int typeLen = argTypes.length. Maybe struts is "confused" because the class org.hibernate.exception.NestableRuntimeException contains two methods called getMessage one without and one with an int as parameter. I'll try to create a minimal example to reproduce the behaviour as soon as possible.

The main problem with this issue is that the stack trace of the former exception is swallowed, not printed in the logfile or anywhere else. Please check and hopefully fix this it took some hours to understand what the reason of this error is.

Issue Links

• breaks: WW-4103 When an action is not found an error which cannot be silenced is logged when not in dev mode
• breaks: WW-4191 Excessive 404 error logging