[JEXL-17] ExpressionFactory.createNewExpression should throw an Exception in case of a parsing error, not Error

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0
• Fix Version/s: 1.1
• Assignee: Unassigned
• Reporter: Kohsuke Kawaguchi
• Created: 05/Aug/06 19:01
• Updated: 09/Mar/10 15:25
• Resolved: 06/Aug/06 18:37

Description

When ExpressionFactory.createNewExpression(...) takes an syntactically incorrect expression, JEXL throws TokenMgrError. However, typical callers (such as Jelly) don't expect such syntax error to be a java.lang.Error, so it fails to catch it.

A typical outcome is therefore the thread to die completely, and even worse the stack trace doesn't report neither what was the expression that was being parsed, nor does it report any contextual information (again in case of Jelly, that would be where in the jelly script this error happened.)

This makes the error diagnosis unnecessarily hard. I believe the proper thing to do is to wrap such an exception into java.lang.Exception or its sub-class, allowing the caller to catch it.