NiFi ExecuteGroovyScript无法解决的类JSch

该groovyscript以下是用于获取文件，从远程机器使用蔽. 我需要获取文件使用蔽

import groovy.json.JsonSlurper
import com.jcraft.jsch.*

java.util.Properties config = new java.util.Properties()
config.put "StrictHostKeyChecking", "no"

JSch ssh = new JSch()
def rfile = "/path/to/remote/file/on/remote/host";
Session sess = ssh.getSession 'user','host', 22
sess.with {
setConfig config
setPassword password
connect()
Channel chan = openChannel "sftp"
chan.connect()
ChannelSftp sftp = (ChannelSftp) chan;

def flowFile = session.get()
if(!flowFile) return
flowFile.write{rawIn, rawOut->
    def keyValueList = rawIn.withReader("UTF-8"){ new JsonSlurper().parse(it) }
    sftp.get("rfile/abc.txt").withReader("UTF-8"){reader->
        rawOut.withWriter("UTF-8"){writer->
            reader.eachLine{line->
               keyValueList.each{ if(it.Key) line = line.replaceAll(it.Key, it.Value) }
               writer << line << '\n'
            }
        }
    }
}
chan.disconnect()
disconnect()
REL_SUCCESS << flowFile
}

越来越错误：

 unable to resolve class JSch @ line 7, column 6. JSch ssh = new JSch()  org.codehaus.groovy.syntax.SyntaxException

我使用的进口 import com.jcraft.jsch.* 但它似乎JSch类是不可或进口是不适当的。