Jim, 1) The line
text = IOUtils.toString(inputStream, StandardCharsets.UTF_8) is for reading the whole content in as a UTF-8 encoded string. The inputStream itself deals in bytes [1] , so you could use available() and read() to get the binary data. 2) If you are not dealing in strings/text, you won't need the encoding, so yes I imagine your write() will look the way you have it above. Regards, Matt [1] https://docs.oracle.com/javase/8/docs/api/java/io/InputStream.html On Fri, Nov 3, 2017 at 5:48 AM, James McMahon <jsmcmah...@gmail.com> wrote: > Thank you Andy. I'd like to ask just a few quick follow up questions. > > 1- My flow content may be textual characters, and it can also be binary - > jpgs, pngs, and similar. How can discern binary or character content using > conditional checks to be sure I handle the file properly? How would I alter > this > > text = IOUtils.toString(inputStream, StandardCharsets.UTF_8) > > to read in the data from the stream as binary data in that case? > > 2- In the case where my data in the flowfile payload is binary, do I have > another version of this.... > > outputStream.write(bytearray(reversedText.encode('utf-8'))) > > ....that omits the encoding, like so: > > outputStream.write(bytearray(some_binary)) ? > > Thank you very much in advance. -Jim > > On Thu, Nov 2, 2017 at 8:26 PM, Andy LoPresto <alopre...@apache.org> wrote: >> >> James, >> >> The Python API should be the same as the Java FlowFile.java interface [1]. >> Matt Burgess’ blog has a good post about using Jython to do flowfile content >> manipulation. Something like: >> >> flowFile = session.get() >> if (flowFile != None): >> flowFile = session.write(flowFile,PyStreamCallback()) >> session.transfer(flowFile, REL_SUCCESS) >> >> With PyStreamCallback declared as a class above that block in the script: >> >> import java.io >> from org.apache.commons.io import IOUtils >> from java.nio.charset import StandardCharsets >> from org.apache.nifi.processor.io import StreamCallback >> >> class PyStreamCallback(StreamCallback): >> def __init__(self): >> pass >> def process(self, inputStream, outputStream): >> text = IOUtils.toString(inputStream, StandardCharsets.UTF_8) >> reversedText = text[::-1] >> >> outputStream.write(bytearray(reversedText.encode('utf-8'))) >> >> In Groovy, you can declare the StreamCallback as an inline closure to make >> this more compact, but I believe in Jython it needs to be a separate >> declaration. Hope this helps. >> >> [1] >> https://github.com/apache/nifi/blob/master/nifi-api/src/main/java/org/apache/nifi/flowfile/FlowFile.java >> [2] >> https://funnifi.blogspot.com/2016/03/executescript-json-to-json-revisited_14.html >> >> >> Andy LoPresto >> alopre...@apache.org >> alopresto.apa...@gmail.com >> PGP Fingerprint: 70EC B3E5 98A6 5A3F D3C4 BACE 3C6E F65B 2F7D EF69 >> >> On Nov 2, 2017, at 12:53 PM, James McMahon <jsmcmah...@gmail.com> wrote: >> >> In python, I can use the requests library to post content something like >> htis: >> >> import requests >> url="https://abc.test.org"; >> files={'file':open('/somedir/myfile.txt','rb')} >> r = requests.post(url,files=files) >> >> If I am in a python stream callback, how can I read the flowfile payload >> in the same way that the open() reads its file from disk? >> >> >
