[CAY-2166] Auto-loading of Cayenne modules

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.M5
• Assignee: Andrus Adamchik
• Reporter: Andrus Adamchik
• Created: 11/Dec/16 14:05
• Updated: 11/Dec/16 18:29
• Resolved: 11/Dec/16 18:29

Description

We need to borrow the central modularity feature from bootique.io - module auto-loading based on Java ServiceLoader:

1. Each module in Cayenne (or custom modules if a user so desires) will ship with "META-INF/services/org.apache.cayenne.di.spi.ModuleProvider" file that will contain the name of the provider class.

2. Provider will contain a factory method for the module, as well as a method that returns a collection of modules that this module "overrides"

3. There will be a loader class that will load all providers via "java.util.ServiceLoader", create modules for each provider and then sort them in the order of override dependencies.

4. ServerRuntimeBuilder will contain a method to turn auto-loading on and off. "on" will be the default.