Framework Recommendations for AppEngine Java8 Standard

[Eric Martineau]

When we started building AppEngine Java7, the community recommendation and examples were centered around using Guice+Jersey.  Despite having a long history with SpringBoot, our company invested in Guice/Jersey infrastructure for AppEngine.

Since the release of java8, there are a few observations that lead us to wonder if Guice+Jersey is still the recommended path:

* The emergence of Spring Cloud GCP (primarily developed by Google)

* Inclusion of SpringBoot examples in getting-started-java (not seeing any Guice/Jersey examples)

* A Google Codelab dedicated to SpringBoot in AppEngine

Is there any formal/informal recommendation for Java8 AppEngine between Spring vs Guice+Jersey?

[Kenworth (Google Cloud Platform)]

Guice is a 'lightweight' Dependency Injection (DI) framework. Spring has one as well, but it has way much more than Guice. Originally, Spring is a DI framework, but now it has tons of facilities/helpers on top of it like SpringBoot, SpringData, etc. The rule of thumb is that if a user only needs a DI framework, then Guice is enough. 

See also Guice and Spring Comparison.