java AbstractMethodError

Question

How to handle this error in lucene:

java.lang.AbstractMethodError: org.apache.lucene.store.Directory.listAll()[Ljava/lang/String;
        at org.apache.lucene.index.SegmentInfos$FindSegmentsFile.run(SegmentInfos.java:568)
        at org.apache.lucene.index.DirectoryReader.open(DirectoryReader.java:69)
        at org.apache.lucene.index.IndexReader.open(IndexReader.java:316)
        at org.apache.lucene.index.IndexReader.open(IndexReader.java:188)

I am making a lucene function call but unfortunately it itself calls an abstract method of some class, as is evident from the error above. What is the work around for this?

Thanks, Akhil

Answer 1

An AbstractMethodError can only occur when a class definition has changed incompatibly, so it looks like you're using an incompatible combination of JARs of different parts of Lucene. Try updating all your Lucene JARs to the latest version.

Answer 2

Another option is that something bad happened to your index - either it was built using a different version of Lucene, or a file is missing. Try opening the index using luke.

Answer 3

Ok! I found the answer. It was not the problem of version mismatch. Rather the hadoop contrib's FileSystemDirectory which extends abstract class Directory did not implement the abstract function listAll(). listAll() function was being called by lucene indexReader.open() function. I added this function and it is up and running now.

Thanks