问题
I keep adding the classpath in the java command line yet I get this error. what could be the issue?
~/Documents/solr-5.5.5/server/solr-webapp/webapp/WEB-INF/lib $ java -classpath ./lucene-backward-codecs-5.5.5.jar -cp lucene-core-5.5.5.jar org.apache.lucene.index.IndexUpgrader -delete-prior-commits -verbose ~/Documents/zaobao_cms/collection1/data/index/
IW 0 [2019-01-17T13:39:11.649Z; main]: init: hit exception on init; releasing write lock
Exception in thread "main" java.lang.IllegalArgumentException: Could not load codec 'Lucene410'. Did you forget to add lucene-backward-codecs.jar?
at org.apache.lucene.index.SegmentInfos.readCodec(SegmentInfos.java:481)
at org.apache.lucene.index.SegmentInfos.readCommit(SegmentInfos.java:361)
at org.apache.lucene.index.IndexWriter.<init>(IndexWriter.java:910)
at org.apache.lucene.index.IndexUpgrader.upgrade(IndexUpgrader.java:167)
at org.apache.lucene.index.IndexUpgrader.main(IndexUpgrader.java:78)
Caused by: java.lang.IllegalArgumentException: An SPI class of type org.apache.lucene.codecs.Codec with name 'Lucene410' does not exist. You need to add the corresponding JAR file supporting this SPI to your classpath. The current classpath supports the following names: [Lucene54]
at org.apache.lucene.util.NamedSPILoader.lookup(NamedSPILoader.java:114)
at org.apache.lucene.codecs.Codec.forName(Codec.java:113)
at org.apache.lucene.index.SegmentInfos.readCodec(SegmentInfos.java:469)
... 4 more
来源：https://stackoverflow.com/questions/54237232/unable-to-run-solr-5-index-upgrader