I recently attended the SBJUG talk on Dropwizard, which is less of a framework than a collection of libraries for developing self-contained REST web services. I had been hearing a lot of buzz about it recently and wanted to see how it compared to Grails. It is definitely lightweight and I’d encourage you to check it out. However, if you are an experienced Spring developer, your time might be better spent learning Spring boot and using that collection of libraries. If you know Grails, you might just be able to start using 2.4, which allows the @CompileStatic annotation in controllers and domain classes, which could really speed things up. For various reasons you may not be a fan of Spring, and if that’s the case definitely check out Dropwizard.
Although it’s not for me, I did learn about two cool libraries that could be incorporated into any project:
JDBI is like the sequel to iBATIS. You use straight SQL – no HQL or equivalent – with convenience features for writing DAOs to map to classes. No XML. Seems appropriate for groups where most of the queries are hand written for performance or religious reasons.
Metrics is a performance measurement/profiling library. Looks handy. Like Dropwizard, it’s a Yammer project.