That is correct behaviour, because the target of copyTo must support all interfaces implemented (see docs). So you cannot copy a Token to a TermAttribute (because it would be a loss in information), but the other way round is possible.
----- Uwe Schindler H.-H.-Meier-Allee 63, D-28213 Bremen http://www.thetaphi.de eMail: u...@thetaphi.de _____ From: Shai Erera [mailto:ser...@gmail.com] Sent: Monday, November 23, 2009 12:19 PM To: java-dev@lucene.apache.org Subject: Bug in Token.copyTo? Hi I think that Token.copyTo is buggy. It checks if the AttributeImpl is instanceof Token, and if so reinits. However if it's not, it casts AttributeImpl to *ALL* of TermAttribute, OffsetAttribute, PositionIncrementAttribute etc. and sets them w/ the proper values. However, one can pass an AttributeImpl which is not Token, but one of its implementing interfaces, such as TermAttribute, and then the code breaks w/ a ClassCastException. There's nothing in the API which prevents me from passing a non-Token instance, and more than that - it looks as if the code tries to optimize for a Token instance, but does not handle properly other cases. I think the 'else' clause should include instanceof checks, because obviously I cannot pass an instance that implements all of the interfaces and is not Token (well I can, but what's the point, just use Token). Here is a short example which reproduces: Token token = new Token("hello", 0, 5); TermAttributeImpl term = new TermAttributeImpl(); token.copyTo(term); System.out.println(term); Shai
