Chapter 15. Understanding events, messaging, and scheduling


This chapter covers

  • Working with Platform Core’s lightweight messaging
  • Working with JMS messaging
  • Implementing queues and topics
  • Scheduling jobs using Quartz and cron
  • Using Quartz for advanced scheduling tasks

In chapter 14, you investigated how Spring integrates with Grails, including the trickier uses of transactions. In this chapter, we keep you in that enterprise headspace by looking at sending intraapplication messages. In particular, you examine how different components in an application can communicate internally while different events in the application’s lifecycle unfold. One of the most popular ways of doing that is via messaging queues, an architecture sometimes referred to as message-oriented middleware (MOM).

If you’ve been around enterprise circles for a while, you’ve probably used or heard of MOM architectures. You may think it’s a heavyweight old-school technology that won’t die. Nothing could be further from the truth. In fact, with the birth of service-oriented architectures (SOAs), Enterprise Service Bus (ESB), and the rise of massive social networking sites, you’re experiencing an explosion of interest in messaging architectures.

15.1. Lightweight messaging with Platform Core

15.2. A hitchhiker’s guide to JMS messaging

15.3. Using the Grails JMS plugin

15.4. Scheduling tasks with Grails

15.5. Advanced scheduling

15.6. Summary and best practices