jvmjythonsnaplogicsnaplogic-script-snap

How to convert Python script to JVM in snaplogic


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()   

Solution

  • 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.