Guidelines

Java Code

In general, refer to http://en.wikipedia.org/wiki/The_Elements_of_Java_Style , make sure you understand and apply http://en.wikipedia.org/wiki/SOLID_(object-oriented_design).

• Always implement against interfaces, never concrete types.
• Write short classes: 100 lines is good, 200 lines is long, and everything beyond has to be split up
• Avoid deep nesting levels
• Avoid if-else constructs, consider breaking up into smaller classes or guardians.
• Extend java.lang.RuntimeException. Unchecked exceptions are much easier to handle and organize. Make all exceptions inherit ObjectMapperException.
• Write comments. If you add a class or an interface, at least add a line saying what problem this class solves, even if it's absolutely clear to you.
  • Use JavaDoc style comments before classes, fields and methods
  • Use double slash comments for inline comments
  • Don't comment the obvious.
  • Write comments that
• Format your code, use the supplied eclipse formatter settings.
• Organize your imports

API

• Do not touch the API in core/api unless you have a really good reason for it.
• Everything in core/api is independent of the actual persistence backends. Never ever add dependencies to concrete persistence subsystems.
• Be considerate with external dependencies. Be aware of transitive dependencies. We're building a library and we don't want to invade projects with a whole host of dependencies.