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
<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
<https://funnifi.blogspot.com/2016/03/executescript-json-to-json-revisited_14.html>
Andy LoPresto
[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 <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?
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