Net::Stomp(3pm)

NAME
Net::Stomp - A Streaming Text Orientated Messaging Protocol Client

SYNOPSIS
  # send a message to the queue 'foo'
  use Net::Stomp;
  my $stomp = Net::Stomp->new( { hostname => 'localhost', port => '61613' } );
  $stomp->connect( { login => 'hello', passcode => 'there' } );
  $stomp->send(
      { destination => '/queue/foo', body => 'test message' } );
  $stomp->disconnect;

  # subscribe to messages from the queue 'foo'
  use Net::Stomp;
  my $stomp = Net::Stomp->new( { hostname => 'localhost', port => '61613' } );
  $stomp->connect( { login => 'hello', passcode => 'there' } );
  $stomp->subscribe(
      {   destination             => '/queue/foo',
          'ack'                   => 'client',
          'activemq.prefetchSize' => 1
      }
  );
  while (1) {
    my $frame = $stomp->receive_frame;
    warn $frame->body; # do something here
    $stomp->ack( { frame => $frame } );
  }
  $stomp->disconnect;

  # write your own frame
  my $frame = Net::Stomp::Frame->new(
       { command => $command, headers => $conf, body => $body } );
  $self->send_frame($frame);

  # connect with failover supporting similar URI to ActiveMQ
  $stomp = Net::Stomp->new({ failover => "failover://tcp://primary:61616" })
  # "?randomize=..." and other parameters are ignored currently
  $stomp = Net::Stomp->new({ failover => "failover:(tcp://primary:61616,tcp://secondary:61616)?randomize=false" })

  # Or in a more natural perl way
  $stomp = Net::Stomp->new({ hosts => [
    { hostname => 'primary', port => 61616 },
    { hostname => 'secondary', port => 61616 },
  ] });

DESCRIPTION
This module allows you to write a Stomp client. Stomp is the Streaming Text Orientated Messaging Protocol (or the Protocol Briefly Known as TTMP and Represented by the symbol :ttmp). It's a simple and easy to implement protocol for working with Message Orientated Middleware from any language. Net::Stomp is useful for talking to Apache ActiveMQ, an open source (Apache 2.0 licensed) Java Message Service 1.1 (JMS) message broker packed with many enterprise features.

A Stomp frame consists of a command, a series of headers and a body - see Net::Stomp::Frame for more details.

For details on the protocol see <http://stomp.codehaus.org/Protocol>.

To enable the ActiveMQ Broker for Stomp add the following to the activemq.xml configuration inside the <transportConnectors> section:

  <transportConnector name="stomp" uri="stomp://localhost:61613"/>

To enable the ActiveMQ Broker for Stomp and SSL add the following inside the <transportConnectors> section:

  <transportConnector name="stomp+ssl" uri="stomp+ssl://localhost:61612"/>

For details on Stomp in ActiveMQ See <http://activemq.apache.org/stomp.html>.

METHODS

  new
The constructor creates a new object. You must pass in a hostname and a port or set a failover configuration:

  my $stomp = Net::Stomp->new( { hostname => 'localhost', port => '61613' } );

If you want to use SSL, make sure you have IO::Socket::SSL and pass in the SSL flag:

  my $stomp = Net::Stomp->new( {
    hostname => 'localhost',
    port     => '61612',
    ssl      => 1,
  } );

If you want to pass in IO::Socket::SSL options:

  my $stomp = Net::Stomp->new( {
    hostname    => 'localhost',
    port        => '61612',
    ssl         => 1,
    ssl_options => { SSL_cipher_list => 'ALL:!EXPORT' },
  } );

Failover

There is experiemental failover support in Net::Stomp. You can specify failover in a similar maner to ActiveMQ (<http://activemq.apache.org/failover-transport-reference.html>) for similarity with Java configs or using a more natural method to perl of passing in an array-of-hashrefs in the "hosts" parameter.

Currently when ever Net::Stomp connects or reconnects it will simply try the next host in the list.

Reconnect on "fork"

By default Net::Stomp will reconnect, using a different socket, if the process "fork"s. This avoids problems when parent & child write to the socket at the same time. If, for whatever reason, you don't want this to happen, set "reconnect_on_fork" to 0 (either as a constructor parameter, or by calling the method).

  connect
This connects to the Stomp server. You may pass in a "login" and "passcode" options.

You may also pass in 'client-id', which specifies the JMS Client ID which is used in combination to the activemqq.subscriptionName to denote a durable subscriber.

  $stomp->connect( { login => 'hello', passcode => 'there' } );

  send
This sends a message to a queue or topic. You must pass in a destination and a body.

  $stomp->send(
      { destination => '/queue/foo', body => 'test message' } );

To send a BytesMessage, you should set the field 'bytes_message' to 1.

  send_transactional
This sends a message in transactional mode and fails if the receipt of the message is not acknowledged by the server:

  $stomp->send_transactional(
      { destination => '/queue/foo', body => 'test message' }
  ) or die "Couldn't send the message!";

If using ActiveMQ, you might also want to make the message persistent:

  $stomp->send_transactional(
      { destination => '/queue/foo', body => 'test message', persistent => 'true' }
  ) or die "Couldn't send the message!";

  disconnect
This disconnects from the Stomp server:

  $stomp->disconnect;

  subscribe
This subscribes you to a queue or topic. You must pass in a destination.

The acknowledge mode defaults to 'auto', which means that frames will be considered delivered after they have been sent to a client. The other option is 'client', which means that messages will only be considered delivered after the client specifically acknowledges them with an ACK frame.

Other options:

'selector': which specifies a JMS Selector using SQL 92 syntax as specified in the JMS 1.1 specificiation. This allows a filter to be applied to each message as part of the subscription.

'activemq.dispatchAsync': should messages be dispatched synchronously or asynchronously from the producer thread for non-durable topics in the broker. For fast consumers set this to false. For slow consumers set it to true so that dispatching will not block fast consumers.

'activemq.exclusive': Would I like to be an Exclusive Consumer on a queue.

'activemq.maximumPendingMessageLimit': For Slow Consumer Handlingon non-durable topics by dropping old messages - we can set a maximum pending limit which once a slow consumer backs up to this high water mark we begin to discard old messages.

'activemq.noLocal': Specifies whether or not locally sent messages should be ignored for subscriptions. Set to true to filter out locally sent messages.

'activemq.prefetchSize': Specifies the maximum number of pending messages that will be dispatched to the client. Once this maximum is reached no more messages are dispatched until the client acknowledges a message. Set to 1 for very fair distribution of messages across consumers where processing messages can be slow.

'activemq.priority': Sets the priority of the consumer so that dispatching can be weighted in priority order.

'activemq.retroactive': For non-durable topics do you wish this subscription to the retroactive.

'activemq.subscriptionName': For durable topic subscriptions you must specify the same clientId on the connection and subscriberName on the subscribe.

  $stomp->subscribe(
      {   destination             => '/queue/foo',
          'ack'                   => 'client',
          'activemq.prefetchSize' => 1
      }
  );

  unsubscribe
This unsubscribes you to a queue or topic. You must pass in a destination:

  $stomp->unsubcribe({ destination => '/queue/foo' });

  receive_frame
This blocks and returns you the next Stomp frame.

  my $frame = $stomp->receive_frame;
  warn $frame->body; # do something here

The header bytes_message is 1 if the message was a BytesMessage.

By default this method will block until a frame can be returned. If you wish to wait for a specified time pass a "timeout" argument:

  # Wait half a second for a frame, else return undef
  $stomp->receive_frame({ timeout => 0.5 })

  can_read
This returns whether there is new data is waiting to be read from the STOMP server. Optionally takes a timeout in seconds:

  my $can_read = $stomp->can_read;
  my $can_read = $stomp->can_read({ timeout => '0.1' });

"undef" says block until something can be read, 0 says to poll and return immediately.

  ack
This acknowledges that you have received and processed a frame (if you are using client acknowledgements):

  $stomp->ack( { frame => $frame } );

  send_frame
If this module does not provide enough help for sending frames, you may construct your own frame and send it:

  # write your own frame
  my $frame = Net::Stomp::Frame->new(
       { command => $command, headers => $conf, body => $body } );
  $self->send_frame($frame);

SEE ALSO
Net::Stomp::Frame.

AUTHORS
Leon Brocard <acme@astray.com>, Thom May <thom.may@betfair.com>, Michael S. Fischer <michael@dynamine.net>, Ash Berlin <ash_github@firemirror.com>

CONTRIBUTORS
Paul Driver <frodwith@cpan.org>, Andreas Faafeng <aff@cpan.org>, Vigith Maurice <vigith@yahoo-inc.com>, Stephen Fralich <sjf4@uw.edu>, Squeeks <squeek@cpan.org>, Chisel Wright <chisel@chizography.net>,

COPYRIGHT
Copyright (C) 2006-9, Leon Brocard Copyright (C) 2009, Thom May, Betfair.com Copyright (C) 2010, Ash Berlin, Net-a-Porter.com Copyright (C) 2010, Michael S. Fischer

This module is free software; you can redistribute it or modify it under the same terms as Perl itself.