Return repo_metadata from repository_rules (#367)

This is used by bazel to determine that these rules are remotely
cacheable with the remote repo contents cache.

Closes #367

COPYBARA_INTEGRATE_REVIEW=https://github.com/bazelbuild/rules_java/pull/367 from keith:ks/return-repo_metadata-from-repository_rules f9d9c79fce4d90ca021368b268dac7fd4a879b8c
PiperOrigin-RevId: 946959010
Change-Id: Ic5537bf0e2b825d67061be55f61250e770e279b7

java/rules_java_deps.bzl

diff --git a/java/rules_java_deps.bzl b/java/rules_java_deps.bzl
index b2086dc..c9742f9 100644
--- a/java/rules_java_deps.bzl
+++ b/java/rules_java_deps.bzl
@@ -103,6 +103,10 @@
             """,
         )
 
+    if hasattr(rctx, "repo_metadata"):
+        return rctx.repo_metadata(reproducible = True)
+    return None
+
 _compatibility_proxy_repo_rule = repository_rule(
     _compatibility_proxy_repo_impl,
     # force reruns on server restarts to use correct native.bazel_version

toolchains/local_java_repository.bzl

diff --git a/toolchains/local_java_repository.bzl b/toolchains/local_java_repository.bzl
index 769c2d1..88115bb 100644
--- a/toolchains/local_java_repository.bzl
+++ b/toolchains/local_java_repository.bzl
@@ -176,6 +176,10 @@
       repository_ctx: repository context
     """
 
+    repository_metadata = None
+    if hasattr(repository_ctx, "repo_metadata"):
+        repository_metadata = repository_ctx.repo_metadata(reproducible = True)
+
     java_home = _determine_java_home(repository_ctx)
 
     local_java_runtime_name = repository_ctx.attr.runtime_name
@@ -198,7 +202,7 @@
                       "either correct your JAVA_HOME, PATH or specify Java from " +
                       "remote repository (e.g. --java_runtime_version=remotejdk_11)",
         )
-        return
+        return repository_metadata
 
     # Detect version
     version = repository_ctx.attr.version if repository_ctx.attr.version != "" else _detect_java_version(repository_ctx, java_bin)
@@ -211,7 +215,7 @@
             message = "Cannot detect Java version of {java_binary} in {java_home}; " +
                       "make sure it points to a valid Java executable",
         )
-        return
+        return repository_metadata
 
     # Prepare BUILD file using "local_java_runtime" macro
     if repository_ctx.attr.build_file_content and repository_ctx.attr.build_file:
@@ -247,6 +251,8 @@
     for file in repository_ctx.path(java_home).readdir():
         repository_ctx.symlink(file, file.basename)
 
+    return repository_metadata
+
 # Build file template, when JDK could not be detected
 _AUTO_CONFIG_ERROR_BUILD_TPL = '''load("@rules_java//toolchains:fail_rule.bzl", "fail_rule")
 fail_rule(

toolchains/remote_java_repository.bzl

diff --git a/toolchains/remote_java_repository.bzl b/toolchains/remote_java_repository.bzl
index 65bbe48..500beb7 100644
--- a/toolchains/remote_java_repository.bzl
+++ b/toolchains/remote_java_repository.bzl
@@ -23,6 +23,9 @@
 def _toolchain_config_impl(ctx):
     ctx.file("WORKSPACE", "workspace(name = \"{name}\")\n".format(name = ctx.name))
     ctx.file("BUILD.bazel", ctx.attr.build_file)
+    if hasattr(ctx, "repo_metadata"):
+        return ctx.repo_metadata(reproducible = True)
+    return None
 
 _toolchain_config = repository_rule(
     local = True,