Messaging Patterns on Enterprise Integration
When two or more applications want to exchange data, they do so by sending the data through a channel that connects to the others. The application sending the data may not know which application will receive the data, but by selecting a particular channel to send the data on, the sender knows that the receiver will be one that is looking for that sort of data by looking for it on that channel.
When designing an application, a developer has to know where to put what types of data to share that data with other applications, and likewise where to look for what types of data coming from other applications. These paths of communication cannot be dynamically created and discovered at runtime; they need to be agreed upon at design time so that the application knows where its data is coming from and where the data is going to. One exception is the reply channel in Request-Reply. The requestor can create or obtain a new channel the replier knows nothing about, specify it as the Return Address of a request message, and then the replier can make use of it. Another exception is messaging system implementations that support hierarchical channels. A receiver can subscribe to a parent in the hierarchy, then a sender can publish to a new child channel the receiver knows nothing about, and the subscriber will still receive the message. https://goo.gl/CkqgyG #DataIntegration #ML