class StompMQAdapter:
"""
Represents a Message Queueing adapter, an object
capable of interacting with a MQ system via Stomp protocol.
"""
# The Stomp connection headers.
headers = {StompSpec.ACK_HEADER: StompSpec.ACK_CLIENT_INDIVIDUAL}
def __init__(self, host, port, version, headers={}):
"""
Creates an instance of the StompMQAdapter class.
Args:
host (str): Hostname or IP address for locating the MQ system.
port (int): The port to connect to.
stomp_version (str): The Stomp protocol version ot be used.
headers (dict, optional): Defaults to {}. The headers to be used in the connection.
"""
self.client = Stomp(
StompConfig('tcp://{}:{}'.format(host, port), version=version))
# Assign mandatory ID_HEADER if version above 1.1
if float(version) > 1.1:
self.headers[StompSpec.ID_HEADER] = id(self.client)
# Add all given headers to object headers
for key in headers.keys():
self.headers[key] = headers[key]
def connect(self):
"""
Connects to the MQ system via Stomp protocol.
Raises:
StompConnectTimeout: Could not connect to STOMP socket.
"""
self.client.connect()
def subscribe(self, queue):
"""
Subscribes to a queue in the MQ system.
Args:
queue (str): The queue to subscribe to.
"""
self.client.subscribe(queue, self.headers)
def queue(self, queue, message):
"""
Sends a message to the specified queue.
Args:
queue (str): The queue to where the message should be queued.
message: The message to be queued.
Raises:
NotImplementedError: Implement this method on a child class.
"""
self.client.send(queue, message.encode())
def retrieve(self):
"""
Retrieves a message from the subscription (queue).
Returns:
object: The message to be consumed or None if the queue is empty.
"""
if self.client.canRead(timeout=2):
return self.client.receiveFrame()
return None
def ack(self, message):
"""
Acknowledges the consumption of the given message.
Args:
message ([type]): The message to be acknowledged.
"""
self.client.ack(message)
def nack(self, message):
"""
Not-acknowledges the consumption of the given message.
Args:
message ([type]): The message to be not-acknowledged.
"""
self.client.nack(message)
def disconnect(self):
"""
Disconnects from the MQ system.
"""
self.client.disconnect()
destination = "/queue/test" #There're more options other than /queue/...
while True:
try:
client = Stomp(
StompConfig("tcp://" + server + ":" + port,
login=login,
passcode=passcode,
version="1.2"))
client.connect(versions=["1.2"], host=vhost,
heartBeats=(0, 60000)) #CONNECT
subscription = client.subscribe(destination, {
"ack": "client",
"id": "0"
}) #SUBSCRIBE
while True:
frame = client.receiveFrame()
try:
print frame.body
client.ack(frame) #ACK
except:
print "Error: Can't handle message received, NACKing"
client.nack(frame) #NACK
except Exception, e:
#reconnect on exception
print "Exception handled, reconnecting...\nDetail:\n%s" % e
try:
client.disconnect()
except:
pass
time.sleep(5)
from stompest.config import StompConfig
from stompest.sync import Stomp
server = "hostname"
port = "61613"
vhost = "yourvhost"
login = "******"
passcode = "password"
destination = "/queue/test" #There're more options other than /queue/...
while True:
try:
client = Stomp(StompConfig("tcp://" + server + ":" + port, login = login, passcode = passcode, version = "1.2"))
client.connect(versions = ["1.2"], host = vhost, heartBeats = (0, 60000)) #CONNECT
subscription = client.subscribe(destination, {"ack": "client", "id": "0"}) #SUBSCRIBE
while True:
frame = client.receiveFrame()
try:
print frame.body
client.ack(frame) #ACK
except:
print "Error: Can't handle message received, NACKing"
client.nack(frame) #NACK
except Exception, e:
#reconnect on exception
print "Exception handled, reconnecting...\nDetail:\n%s" % e
try:
client.disconnect()
except:
pass
time.sleep(5)
