Hello, Since this an R package, I'm sending the email. I'm loading all the jar files as: library(rJava) hadoop <- Sys.getenv("HADOOP") allfiles <- c(list.files(hadoop,pattern="jar$",full.names=T),list.files(paste(hadoop,"lib",sep=.Platform$file.sep,collapse=""),pattern="jar$",full.names=T)) allfiles <- c(allfiles,"/home/sguha/tmp/x/build/jar/rhipe.jar") .jinit(classpath=allfiles) Now, I create a new object .jnew("org/guha/SeqKeyList",.jnull) but get this error Exception in thread "main" java.lang.RuntimeException: java.lang.ClassNotFoundException: org.apache.hadoop.hdfs.DistributedFileSystem at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:720) This does not appear to be possible(ClassNotFound), since hadoop-0.19-core.jar which is *present* in the output of .jclassPath() does contain an entry to this class. Moreover, when run at the command line using the *same* classpath, I don't get any such error messages. Is there a possible reason why? Regards Saptarshi Saptarshi Guha