Protobuf uses Guava 30.1.1, so I upgrade it at the same time. It also
caused an update to rules_jvm_external and reworking the Bazel build.
Protobuf no longer requires bind() so they were dropped. Although
Protobuf's protobuf_deps() brings in rules_jvm_external, and so we don't
need to define it ourselves, it seems better to define it directly and
not depend on transitive deps since we use it directly.
Protobuf now has support for maven_install() by exposing
PROTOBUF_MAVEN_ARTIFACTS, which required reorganizing the WORKSPACE to
use maven_install() after loading protobuf. Protobuf still doesn't
define target overrides for itself so we still maintain those. When
reorganizing the WORKSPACE I noticed http_archive should ideally be
above io_grpc_grpc_java as most users will need it there, so I fixed
that since there were lots of other load()-reordering already.
Manually specifying individual Maven artifacts is very verbose and
error-prone. It also does not properly handle transitive dependencies.
It greatly increases the amount of effort to update dependencies.
v1.27.0 introduced support for maven_install and encouraged users to
migrate. I fully expect some users haven't migrated, but it's not clear
that an additional 8 months would help much. Users that don't want to
use maven_install are still free to do so, but would need to maintain
the verbose repository list themselves.
At some point we may begin using the @maven workspace which would
require maven_install, but are not doing so now (except in the examples)
and don't have immediate plans to start.
maven_install is strongly superior to previous forms of grabbing dependencies
from Maven as it computes the appropriate versions to use from the full
transitive dependencies of all libraries used by an application. It also has
much less boilerplate and includes dependencies with generated targets.
In the future we will drop the jvm_maven_import_external usages and require
maven_install, at which point we can swap to using the `@maven' repository and
no longer depend on compat_repositories.
Fixes#5359
## Bazel
If you prefer to use Bazel:
```
(With Bazel v0.4.5 or above.)
$ bazel build :hello-world-server :hello-world-client
$ # Run the server:
$ bazel-bin/hello-world-server
$ # In another terminal run the client
$ bazel-bin/hello-world-client
```
Eric Anderson
Carl Mastrangelo
sanjaypujare
Carmi Grushko
ZHANG Dapeng