Sending SMS from Maximo calling an external Web service

In my last project I had to implement a customization to send SMS messages using Skebby. The service APIs are obviously based on REST and JSON so I ended up writing an automation script to integrate Maximo with the Skebby service.
In the process of writing the code I have faced (and solved) some interesting issues so the developed script is quite complex and is an interesting demonstration of several useful techniques:

1. External REST service invocation (POST and GET)
2. JSON manipulation
3. Retrieve Maximo system properties
4. Usage of Java classes
5. Appropriate logging using MXLoggerFactory
6. Display error messages with parameters

The script is based on WORKORDER object and requires two custom system properties (sms.username, sms.password) and two messages (SmsSendError, SmsSendOk).
Here it is.

from java.lang import String
from java.io import BufferedReader, InputStreamReader
from java.net import URL, URLEncoder
from java.nio.charset import StandardCharsets
from com.ibm.json.java import JSONObject, JSONArray

from psdi.server import MXServer
from psdi.util.logging import MXLoggerFactory

logger = MXLoggerFactory.getLogger("maximo.script")
logger.debug("Entering SEND_SMS script")


BASEURL = "https://api.skebby.it/API/v1.0/REST/"
SMS_SENDER = "Maximo"
SMS_DEST = "+3933511111111"

sms_text = "Ticket " + mbo.getString("WONUM") + " - " + mbo.getString("DESCRIPTION")

properties = MXServer.getMXServer().getConfig()
username = properties.getProperty("sms.username")
password = properties.getProperty("sms.password")

urltxt = BASEURL + "login?username=" + URLEncoder.encode(username, "UTF-8") + "&password=" + URLEncoder.encode(password, "UTF-8")
logger.debug("Authenticating: " + urltxt)
url = URL(urltxt)
conn = url.openConnection()
conn.setRequestMethod("GET")

if conn.getResponseCode() != 200:
  conn.disconnect()
  msg = "HTTP Error: " + str(conn.getResponseCode()) + " - " + str(conn.getResponseMessage())
  logger.error(msg)
  service.error("asts", "SmsSendError", [str(conn.getResponseCode()), str(conn.getResponseMessage()), "Authentication failed"])

br = BufferedReader(InputStreamReader(conn.getInputStream()))
authResp = br.readLine()
conn.disconnect()

#logger.debug("Authentication output:" + authResp)
# auth tokens are returned separated by a ';' character
user_key,session_key = authResp.split(';')

logger.debug("Authentication tokens:" + user_key + "," + session_key)

logger.info("Sending SMS to " + SMS_DEST + " - " + sms_text)

url = URL(BASEURL + "sms")
conn = url.openConnection()
conn.setRequestMethod("POST")
conn.setRequestProperty("user_key", user_key)
conn.setRequestProperty("Session_key", session_key)
conn.setRequestProperty("content-type", "application/json")
conn.setDoOutput(True)

recipients = JSONArray()
recipients.add(SMS_DEST)

obj = JSONObject()
obj.put("message_type", "TI")
obj.put("returnCredits", False)
obj.put("sender", SMS_SENDER)
obj.put("recipient", recipients)
obj.put("message", sms_text)
jsonStr = obj.serialize(False)

logger.debug("SMS Json Request=" + jsonStr)

os = conn.getOutputStream()
postData = String.getBytes(jsonStr, StandardCharsets.UTF_8)
os.write(postData)
os.flush()

if conn.getResponseCode() != 201:
  br = BufferedReader(InputStreamReader(conn.getErrorStream()))
  output = br.readLine()
  logger.error("Error: " + output)
  conn.disconnect()
  msg = "HTTP Error: " + str(conn.getResponseCode()) + " - " + str(conn.getResponseMessage() + " - " + output)
  logger.error(msg)
  service.error("asts", "SmsSendError", [str(conn.getResponseCode()), str(conn.getResponseMessage()), output])

br = BufferedReader(InputStreamReader(conn.getInputStream()))
output = br.readLine()
logger.info("OK: " + output)
conn.disconnect()

service.setWarning("asts", "SmsSendOk", None)

The script has been developed to avoid external dependencies like this example.