Garret Wilson created JEXL-388:
----------------------------------
Summary: v3.3-SNAPSHOT doesn't find public getter as property
Key: JEXL-388
URL: https://issues.apache.org/jira/browse/JEXL-388
Project: Commons JEXL
Issue Type: Bug
Affects Versions: 3.3
Environment: Java 17; Windows 10
Reporter: Garret Wilson
In my [Guise Mummy|https://github.com/globalmentor/guise-mummy] static site
generator I'm using JEXL to interpret the built-in [Mesh Expression
Language|https://github.com/globalmentor/guise-mummy/tree/main/mesh] (MEXL).
Everything was working fine with JEXL 3.1. In fact the entire [Guise Mummy web
site|https://guise.io/mummy/] itself was produced using Guise Mummy with MEXL
on top of JEXL. But when I upgrade to JEXL 3.3-SNAPSHOT, a couple of unit tests
break. In particular, the new version doesn't seem to find a public getter
method on a custom public class as a property.
In the Mesh templating, we have an {{mx:each}} attribute (similar to JSP or
Thymeleaf) which loops through and replicates some HTML element (e.g. an
{{<li>}} inside an {{<ul>}}) for each value in a list. It assigns each value,
one at a time, to a variable {{it}} in the context. That is working fine. But
on each iteration it also assigns {{iter}} in the context, with the value being
an instance of
[{{MeshIterator}}|https://github.com/globalmentor/guise-mummy/blob/main/mesh/src/main/java/io/guise/mesh/MeshIterator.java].
That object has, among other things, {{getCurrent()}}:
{code:java}
/**
* Returns the current item. This will be the result of the last successful
call to {@link #next()}.
* @throws NoSuchElementException if iteration has not yet started.
* @return The current item.
*/
public Object getCurrent() { ... }
{code}
To make a long story short, the MEXL expression should be able to use
{{iter.current}} to get the value, but it's not finding it. I traced through
the new code, and it's finding the {{MeshIterator}} instance just fine and
assigning it to {{iter}}. The problem is that JEXL's {{ClassMap}} (probably
inside {{create()}}) is not finding and caching {{getCurrent()}} mapped to the
{{current}} property.
It looks like {{Permissions.allow()}} for method {{MeshIterator.getCurrent()}},
is falling through to the end and returning {{explicit[0]}}, which happens to
be {{false}}. It looks like this comes from {{wildcardAllow(Class<?> clazz)}},
which eventually calls {{wildcardAllow(Set<String> allowed, String name)}}.
There's what I presume to be a set of allowed packages. Is that new? Do we have
to explicitly provide a list of allowed packages for property discovery via
reflection now?
To reproduce this:
# Clone [Guise Mummy
0.5.3|https://github.com/globalmentor/guise-mummy/releases/tag/v0.5.3].
# In the overall project {{pom.xml}}, change the version of
{{org.apache.commons:commons-jexl3}} from {{<version>3.1</version>}} to
{{<version>3.3-SNAPSHOT</version>}}. (You'll also need to add the
{{https://repository.apache.org/content/repositories/snapshots/}} repository in
the POM.}
# Run {{mvn clean verify}}.
You'll see that {{io.guise.mesh.GuiseMeshTest.testMxEachWithIterVar()}} will
fail because {{iter.current}} can't be found.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
