使用JDBC将R连接到Hive

Question

I am trying to connect R to Hive cluster using RJDBC package.

The code I have written is:

drv <- JDBC(driverClass = "org.apache.hive.jdbc.HiveDriver", 
        classPath = list.files("C:/hive-jdbc/hive-jdbc-0.10.0.jar",
                               pattern="jar$",full.names=T),
        identifier.quote="'")

I have added "C:/hive-jdbc" to my system path variable as well.

But I am getting the following error:

Error in path.expand(unlist(strsplit(classPath, .Platform$path.sep))) : 
  invalid 'path' argument

Can some one help me with this?

Answer 1

In

classPath = list.files("C:/hive-jdbc/hive-jdbc-0.10.0.jar",
                               pattern="jar$",full.names=T)

you use list.files . The first argument to list.files should be a folder , you seem to have given it a jar file . What is the output of just that list.files function on your system? It's probably character(0) . That screws up the classPath . Fix that - and its not clear what you want the value of the classPath parameter to be here. If you want it to be all the .jar files in a folder, then

list.files("C:/wherever/", pattern="\.jar$", full.names=TRUE)

should do it. If its just the one jar file, just put it in:

classPath="C:/hive-jdbc/hive-blahlah-999.jar"

in the call. ie, keep it simple!

Answer 2

In answer to Prateek - "Class not found" as it is not in the jar file: you need more jar files in your class path. for me this was:

/usr/lib/hive/lib/hive-jdbc.jar
/usr/lib/hive/lib/libthrift-0.9.2.jar
/usr/lib/hive/lib/hive-service.jar
/usr/lib/hive/lib/httpclient-4.2.5.jar
/usr/lib/hive/lib/httpcore-4.2.5.jar
/usr/lib/hive/lib/hive-jdbc-standalone.jar
/usr/lib/hadoop/client/hadoop-common.jar

(some of these file refs are symbolic links to the real file - take the real file!) I also wrote a basic blow-by-blow article on getting this working: https://pygot.wordpress.com/2016/10/13/connecting-r-studio-to-hadoop-via-hive/