Unless the project is very badly configured, that should be all you need to compile it. Now, writing those .gradle files...
Compiling most Java projects is usually as simple as 'brew install maven; mvn package'. Maven does require a build file, but it can also do more than the go utility, such as deploying artifacts in a repository, build distributable tarballs, RPMs, debs, etc.
Maven, like go, largely relies on convention over configuration as well. If you generate a POM file from the standard archetype, you basically drop your files in the right source directory and it will build.
(I am not a fan of Java, but I think a lot of the criticism here is lazy. The first time you use the 'go' tool you have to learn its usage as well: how to separate library code from programs, what are the conventions for package structure, how to avoid API breakage for downstream users, etc.)
Too many features.