Re-using GAE Python code with GAE Java

Question

Here's a [python code][1] that I would like to know if can also be used for GAE Java (when code is migrated). So the question is, is the python code below something that can converted to Java without any python "dependencies" that Java can't have:

# stdlib
from collections import defaultdict
from datetime import datetime, timedelta
import os
import time

# 3p
import simplejson as json

# google api
from google.appengine.api import app_identity, logservice, memcache, taskqueue
from google.appengine.ext.db import stats as db_stats

# framework
import webapp2

class DatadogStats(webapp2.RequestHandler):
    def get(self):
        api_key = self.request.get('api_key')
        if api_key != os.environ.get('DATADOG_API_KEY'):
            self.abort(403)

        FLAVORS = ['requests', 'services', 'all']

        flavor = self.request.get('flavor')
        if flavor not in FLAVORS:
            self.abort(400)

        def get_task_queue_stats(queues=None):
            if queues is None:
                queues = ['default']
            else:
                queues = queues.split(',')
            task_queues = [taskqueue.Queue(q).fetch_statistics() for q in queues]
            q_stats = []
            for q in task_queues:
                stats = {
                    'queue_name': q.queue.name,
                    'tasks': q.tasks,
                    'oldest_eta_usec': q.oldest_eta_usec,
                    'executed_last_minute': q.executed_last_minute,
                    'in_flight': q.in_flight,
                    'enforced_rate': q.enforced_rate,
                }
                q_stats.append(stats)
            return q_stats
        def get_request_stats(after=None):
            if after is None:
                one_minute_ago = datetime.utcnow() - timedelta(minutes=1)
                after = time.mktime(one_minute_ago.timetuple())
            else:
                # cast to float
                after = float(after)

            logs = logservice.fetch(start_time=after)
            stats = defaultdict(list)
            for req_log in logs:
                stats['start_time'].append(req_log.start_time)
                stats['api_mcycles'].append(req_log.api_mcycles)
                stats['cost'].append(req_log.cost)
                stats['finished'].append(req_log.finished)
                stats['latency'].append(req_log.latency)
                stats['mcycles'].append(req_log.mcycles)
                stats['pending_time'].append(req_log.pending_time)
                stats['replica_index'].append(req_log.replica_index)
                stats['response_size'].append(req_log.response_size)
                stats['version_id'].append(req_log.version_id)
            return stats

        stats = {
            'project_name': app_identity.get_application_id()
        }
        if flavor == 'services' or flavor == 'all':
            stats['datastore'] = db_stats.GlobalStat.all().get()
            stats['memcache'] = memcache.get_stats()
            stats['task_queue'] = get_task_queue_stats(self.request.get('task_queues', None))

        if flavor == 'requests' or flavor == 'all':
            stats['requests'] = get_request_stats(self.request.get('after', None))

        self.response.headers['Content-Type'] = 'application/json'
        self.response.write(json.dumps(stats))

app = webapp2.WSGIApplication([
        ('/datadog', DatadogStats),
        ])


  [1]: https://github.com/DataDog/gae_datadog/blob/master/datadog.py

Answer 1

Yes, the code can be converted and will work in Java, but you will have to do it manually (I don't know of any tools to "translate" from Python to Java).

Looking at all the imports you have, there's nothing there that can't be used in Java.