Java Message Service, 2nd Edition

Messaging Models

JMS supports two types of messaging models: point-to-point and publish-and-subscribe. These messaging models are sometimes referred to as messaging domains. Point-to-point messaging and publish-and-subscribe messaging are frequently shortened to p2p and pub/sub, respectively. This book uses both the long and short forms throughout.

In the simplest sense, publish-and-subscribe is intended for a one-to-many broadcast of messages, while point-to-point is intended for one-to-one delivery of messages (see Figure 1-4).

Figure 1-4. JMS messaging domains

From a JMS perspective, messaging clients are called JMS clients, and the messaging system is called the JMS provider. A JMS application is a business system composed of many JMS clients and, generally, one JMS provider.

In addition, a JMS client that produces a message is called a message producer, while a JMS client that receives a message is called a message consumer. A JMS client can be both a message producer and a message consumer. When we use the term consumer or producer, we mean a JMS client that consumes messages or produces messages, respectively. We use this terminology throughout the book.

Point-to-Point

The point-to-point messaging model allows JMS clients to send and receive messages both synchronously and asynchronously via virtual channels known as queues. In the point-to-point model, message producers are called ...