DbQueue - Database-backed Queue

This is a queue mechanism that is based on a database table and a local thread pool.

Usage

DbQueue is pretty tightly coupled to Spring, particularly so that it can leverage Spring's PlatformTransactionManager abstraction. Use DbQueue as follows:

• create the QueueMessage table as per the given liquibase.xml file
• register an instance of QueueMessageDaoImpl in your application's Spring context
• for each queue you'd like to implement, subclass QueueReader and implement its onMessage(QueueMessage) method

Each QueueReader implements a single thread that reads queue messages with a given name and calls the onMessage method. We don't yet support multi-threaded readers.