Nifi Unable to convert CSV to Excel using POI API
I want to convert csv flowfile content into XLS file usin groovy script + POI API
I m using ivy to grab POI dependencies and it seems work well.
please find more details below:
This is my Nifi flow:

This is my script
import org.apache.poi.ss.usermodel.*
import org.apache.poi.hssf.usermodel.*
import org.apache.poi.xssf.usermodel.*
import org.apache.poi.ss.util.*
import org.apache.poi.ss.usermodel.*
import org.apache.poi.hssf.extractor.*
import java.nio.charset.*
import java.io.*
import org.apache.commons.io.IOUtils
def flowFile = session.get()
def date = new Date()
if(!flowFile) return
flowFile = session.write(flowFile, {inputStream, outputStream ->
try {
Workbook wb = WorkbookFactory.create(inputStream,);
Sheet mySheet = wb.getSheetAt(0);
def record = IOUtils.toString(inputStream, StandardCharsets.UTF_8)
outputStream.write(record.getBytes(StandardCharsets.UTF_8))
wb.close();
} catch(e) {
log.error("Error during processing", e)
session.transfer(flowFile, REL_FAILURE)
}
} as StreamCallback)
def filename = flowFile.getAttribute('filename')+'.xlsx'
flowFile = session.putAttribute(flowFile, 'filename', filename)
session.transfer(flowFile, REL_SUCCESS)
I get this error

Any idea about this error ?

