[sehrope]

> If your app needs a relational database then use an in-memory db like hsql or cloud services like Heroku Postgres, RDS, Redis Labs, etc. However one risk with most in-memory databases is that they differ from what is used in production. JPA / Hibernate try to hide this but sometimes bugs crop up due to subtle differences. So it is best to mimic the production services for developers even down to the version of the database.

The idea that you can develop locally or test against a different type of database then what you are (or will be) using in production is silly. I don't just think it "sometimes" is a bad idea, I reject it outright. You should always be using the exact same database (type and version).

For cloud deployments most XaaS providers have cheap or free dev tiers. For local development it's easy to use VMs. For any project that requires external resources (Postgres, Redis, RabbitMQ, etc) I have a VM that gets spun up via Vagrant[1]. Just "vagrant up" and all external resources required by the app should be available.

> So first… Use a build tool. It doesn’t matter if you choose Ant + Ivy, Maven, Gradle, or sbt. Just pick one and use it to automatically pull your dependencies from Maven Central or your own Artifactory / Nexus server. With WebJars you can even manage your JavaScript and CSS library dependencies. Then get fancy by automatically denying SCM check-ins that include Jar files.

Though I agree that it's a good idea to have dependencies externalized, it's not always possible. Some libraries (ex: third party JARs) are not available in public Maven repos and not everyone has a private one setup. In those situations it's fine to check in the JAR into the project itself.

I like the approach outlined by Heroku for dealing with unmanaged dependencies[2]. You declare them normally in your pom.xml but also include the path to a local directory (checked into SCM) with the JAR files. Anybody that clones your repo should be able to build the project with no manual steps. Works great!

[1]: https://www.vagrantup.com/

[2]: https://devcenter.heroku.com/articles/local-maven-dependenci...