Andy, regarding the the code sample you offered above - doesn't this put into text both the attributes metadata and the payload of the flowfile?
If that is the case, how does one modify that to read in from the stream into variable text only the file payload? On Fri, Nov 3, 2017 at 5:48 AM, James McMahon <[email protected]> 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 <[email protected]> > 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 >> [email protected] >> *[email protected] <[email protected]>* >> PGP Fingerprint: 70EC B3E5 98A6 5A3F D3C4 BACE 3C6E F65B 2F7D EF69 >> >> On Nov 2, 2017, at 12:53 PM, James McMahon <[email protected]> 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? >> >> >> >
