[ https://issues.apache.org/jira/browse/PIG-1288?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Daniel Dai updated PIG-1288: ---------------------------- Status: Resolved (was: Patch Available) Hadoop Flags: [Reviewed] Resolution: Fixed Tested manually. Patch committed. > EvalFunc returnType is wrong for generic subclasses > --------------------------------------------------- > > Key: PIG-1288 > URL: https://issues.apache.org/jira/browse/PIG-1288 > Project: Pig > Issue Type: Bug > Components: impl > Affects Versions: 0.7.0 > Reporter: Daniel Dai > Assignee: Daniel Dai > Fix For: 0.8.0 > > Attachments: PIG-1288-1.patch, PIG-1288-2.patch, PIG-1288-3.patch, > PIG-1288-4.patch > > > From Garrett Buster Kaminaga: > The EvalFunc constructor has code to determine the return type of the > function. > This walks up the object hierarchy until it encounters EvalFunc, then calls > getActualTypeArguments and extracts type > param 0. > However, if the user class is itself a generic extension of EvalFunc, then > the returned object is not the correct type, > but a TypeVariable. > Example: > class MyAbstractEvalFunc<T> extends EvalFunc<T> ... > class MyEvalFunc extends MyAbstractEvalFunc<String> ... > when MyEvalFunc() is called, inside EvalFunc constructor the return type is > set to a TypeVariable rather than > String.class. > The workaround we've implemented is for the MyAbstractEvalFunc<T> to > determine *its* type parameters using code > similar to that in the EvalFunc constructor, and then reset protected data > member returnType manually in the > MyAbstractEvalFunc constructor. (though this has the same drawback of not > working if someone then extends > MyAbstractEvalFunc) -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.