Glossary

Destination

Virtual channel to exchange JMS messages. There are two kinds of destinations; queue and topic. A destination is created in a server, and a client refers to the objects in the server through JNDI Lookup.

Durable Subscriber

A kind of booking system for message reception, which is for overcoming a time limit when a message receiver gets a message from a topic in the Pub/Sub messaging mode. A client can receive messages which arrive after booking by creating a message receiver when needed.

Filtering

Selects a particular message which meets a condition.

JMS

Java EE service which enables an application to create, send, and receive messages.

JMS Connection

The firstly created object in using JMS service. It defines a basic interface to exchange resources (e.g. physical connection and thread pool) and messages. It plays a role as a factory creating an actual JMS session.

JMS Connection Factory

Used by JMS client to create a connection, and managed by JMS server. It has information about connection and basic settings of a client, and it is obtained by JNDI.

JMS Server

Library and the service, offered by JMS service provider. It is also called Message Broker. It manages resources such as destination and connection factory, and also stores or transmits a message.

JMS Session

Provides a single thread context where a message is actually transmitted and received. It is included in a transaction task, and created by a connection.

Message

General information unit which is used to exchange information via JMS. It includes information required for messaging, as well as a user's data.

Message Consumer

JMS object to receive a message from a destination. It is created through JMS session. A message can be received either synchronously or asynchronously. It is called Receiver in the PTP(Peer-To-Peer) mode, and Subscriber in the Pub/Sub(Publish/Subscribe) mode.

Message Listener

Registered in a message receiver when processing a message asynchronously. It implements the Callback interface to process a message, and it is processed by a single thread context assigned in JMS session which created the message receiver.

Message Producer

Defines API to send a message to a destination. It is created through JMS session. Various options for transmitting a message are available. It is called Sender in the PTP (Peer-To-Peer) mode, and Publisher in the Pub/Sub(Publish/Subscribe) mode.

Message Selector

String which defines a syntax for selecting preferred messages by using the message's property table.

Queue

Message channel in an FIFO style. Messages transmitted to a queue can be obtained when needed by a consumer, no matter when it was transmitted. The message can be taken only by one consumer.

Thread Pool

Keeps the certain number of threads according to the previously specified policy, in order to effectively perform tasks which happen at the same time for a short or long period of time. It can lower reaction speed by decreasing overhead which creates threads, and also strengthen stability by making a system process tasks that the system is able to handle.

Topic

Virtual message channel, which transmits a message to a consumer which was specified before the message arrived. It transmits a message to 0 or multiple messages consumer(s), and the messages are deleted after transmitted.