Uwe Schindler created LUCENE-6651:
-------------------------------------
Summary: Remove private field reflection (setAccessible) in
AttributeImpl#reflectWith
Key: LUCENE-6651
URL: https://issues.apache.org/jira/browse/LUCENE-6651
Project: Lucene - Core
Issue Type: Improvement
Components: core/other
Affects Versions: 5.2.1
Reporter: Uwe Schindler
Assignee: Uwe Schindler
Fix For: 5.3, Trunk
In AttributeImpl we currently have a "default" implementation of reflectWith
(which is used by toString() and other methods) that uses reflection to list
all private fields of the implementation class and reports them to the
AttributeReflector (used by Solr and Elasticsearch to show analysis output).
Unfortunately this default implementation needs to access private fields of a
subclass, which does not work without doing Field#setAccessible(true). And this
is done without AccessController#doPrivileged()!
There are 2 solutions to solve this:
- Reimplement the whole thing with MethodHandles. MethodHandles allow to access
private fields, if you have a MethodHandles.Lookup object created from inside
the subclass. The idea is to add a protected constructor taking a Lookup object
(must come from same class). This Lookup object is then used to build
methodHandles that can be executed to report the fields. Backside: We have to
require subclasses that want this "automatic" reflection to pass a Lookup
object in ctor's {{super(MethodHandles.lookup())}} call. This breaks backwards
for implementors of AttributeImpls
- The second idea is to remove the whole reflectWith default impl and make the
method abstract. This would require a bit more work in tons of AttributeImpl
classes, but you already have to implement something like this for
equals/hashCode, so its just listing all fields. This would of couse break
backwards, too. So my plan would be to implement the missing methods everywhere
(as if it were abstract), but keep the default implementation in 5.x. We just
would do AccessController.doPrivileged().
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
