Java Reference
In-Depth Information
The building blocks of JMS
The basic building blocks of any JMS application consists of the following:
• Administered objects—connection factories and destinations
• Connections
• Sessions
• Message producers
• Message consumers
• Messages
Some of these elements are explained as follows:
A
connection factory
object encapsulates a set of connection configuration paramet-
ers that have been defined by an administrator. A client uses it to create a connection
with a JMS provider. A connection factory hides provider-specific details from JMS
clients and abstracts administrative information into objects in the Java programming
language.
A
destination
is the component a client uses to specify the target of messages it
produces and the source of messages it consumes. In the point-to-point (PTP) mes-
saging domain, destinations are called queues; in the
publish/subscribe
(
pub/sub
)
messaging domain, destinations are called topics.
A
connection
encapsulates a virtual connection with a JMS provider. A connection
could represent an open TCP/IP socket between a client and a provider service. You
use a connection to create one or more sessions.
A
session
is a single-threaded context for producing and consuming messages. You
use sessions to create message producers, message consumers, and messages.
Sessions serialize the execution of message listeners and provide a transactional
context with which to group a set of sends and receives into an atomic unit of work.
A
message producer
is an object created by a session and is used for sending
messages to a destination. The PTP form of a message producer implements the
QueueSender
interface. The pub/sub form implements the
TopicPublisher
inter-
face.
