How to convert Python script to JVM in snaplogic

Question

The below-mentioned code is working fine but I want to integrate the below-mentioned python script to JVM script to run in SnapLogic tool. Any leads will be very helpful.

import os
import sys

def execute():

    file=open("C:/Python27/snaplogic_file.txt","r")
    header=next(file)
    new_file1=open("C:/Python27/snaplogic_processed_file1.txt",mode='w+')
    new_file1.write(header)
    new_file1.close()
    for line in file:
       new_file=open("C:/Python27/snaplogic_processed_file.txt",mode='w+')
       new_file.write(line)


execute()   

Answer 1

When you select Python in the Script snap it actually means Jython. So, you can, basically, import Java classes in your script.

Following is an implementation where I'm writing a dummy file in the /tmp folder of one of the nodes.

# Import the interface required by the Script snap.
from com.snaplogic.scripting.language import ScriptHook
import java.util
import com.fasterxml.jackson.databind
import java.io

class TransformScript(ScriptHook):
    def __init__(self, input, output, error, log):
        self.input = input
        self.output = output
        self.error = error
        self.log = log

    # The "execute()" method is called once when the pipeline is started
    # and allowed to process its inputs or just send data to its outputs.
    def execute(self):
        self.log.info("Executing Transform script")
        while self.input.hasNext():
            try:
                # Read the next document, wrap it in a map and write out the wrapper
                in_doc = self.input.next()
                wrapper = java.util.HashMap()

                om = com.fasterxml.jackson.databind.ObjectMapper()
                target_file = java.io.File("/tmp/" + in_doc['filename'])
                om.writeValue(target_file, in_doc['content']);

                wrapper['original'] = in_doc
                wrapper['status'] = "success"

                self.output.write(in_doc, wrapper)
            except Exception as e:
                errWrapper = {
                    'errMsg' : str(e.args)
                }
                self.log.error("Error in python script")
                self.error.write(errWrapper)

        self.log.info("Finished executing the Transform script")

# The Script Snap will look for a ScriptHook object in the "hook"
# variable.  The snap will then call the hook's "execute" method.
hook = TransformScript(input, output, error, log)

Following is the input JSON to the Script snap.

[{"filename":"write_test.txt","content":{"id":123,"message":"xyz","valid":true}}]

Check the file in the node.

$ cd /tmp
$ cat write_test.txt
[{"filename":"write_test.txt","content":{"id":123,"message":"xyz","valid":true}}]

Note: I use Jackson's ObjectMapper because I mostly deal with JSONs.