Rename maven install back to maven in MODULE.bazel

Fixes #21177

This PR essentially reverts #18641, which claimed

> Since protobuf is not contributing to user's JARs

This is not true since targets like `@com_google_protobuf//:protobuf_java` are meant to be consumed by other projects, therefore protobuf should not use a private maven install namespace. Otherwise, it leads to duplicated maven jars and classpath conflicts. See #21177 and bazel-contrib/rules_jvm_external#916 (comment)

The original warning message caused by multiple modules contributing to `maven` can be suppressed with bazel-contrib/rules_jvm_external#1393, which will be available in rules_jvm_external 6.8.

Closes #22544

PiperOrigin-RevId: 782032198

Author: protobuf-github-bot

MODULE.bazel

@@ -174,6 +174,7 @@ crate.spec(
 crate.from_specs()
 use_repo(crate, crate_index = "crates")
 
+# Keep this list minimal; these dependencies will be part of the common `maven` install and could affect end-user projects.
 PROTOBUF_MAVEN_ARTIFACTS = [
     "com.google.code.findbugs:jsr305:3.0.2",
     "com.google.code.gson:gson:2.8.9",
@@ -182,17 +183,19 @@ PROTOBUF_MAVEN_ARTIFACTS = [
     "com.google.guava:guava:32.0.1-jre",
 ]
 
-protobuf_maven = use_extension("@rules_jvm_external//:extensions.bzl", "maven")
-protobuf_maven.install(
-    name = "protobuf_maven",
+maven = use_extension("@rules_jvm_external//:extensions.bzl", "maven")
+maven.install(
     artifacts = PROTOBUF_MAVEN_ARTIFACTS,
     lock_file = "//:maven_install.json",
     repositories = [
         "https://repo1.maven.org/maven2",
         "https://repo.maven.apache.org/maven2",
     ],
 )
-use_repo(protobuf_maven, "protobuf_maven")
+
+# Use the default "maven" namespace because protobuf java targets are exposed to users
+# See https://github.com/protocolbuffers/protobuf/issues/21177
+use_repo(maven, "maven")
 
 # Temporarily pin transitive dependency for https://github.com/bazelbuild/bazel/issues/24426
 bazel_dep(name = "re2", version = "2024-07-02.bcr.1")

WORKSPACE

@@ -65,7 +65,7 @@ rules_jvm_external_setup()
 load("@rules_jvm_external//:defs.bzl", "maven_install")
 
 maven_install(
-    name = "protobuf_maven",
+    name = "maven",
     artifacts = PROTOBUF_MAVEN_ARTIFACTS,
     # For updating instructions, see:
     # https://github.com/bazelbuild/rules_jvm_external#updating-maven_installjson
@@ -76,7 +76,7 @@ maven_install(
     ],
 )
 
-load("@protobuf_maven//:defs.bzl", "pinned_maven_install")
+load("@maven//:defs.bzl", "pinned_maven_install")
 
 pinned_maven_install()
 

examples/WORKSPACE

@@ -76,7 +76,7 @@ rules_jvm_external_setup()
 load("@rules_jvm_external//:defs.bzl", "maven_install")
 
 maven_install(
-    name = "protobuf_maven",
+    name = "maven",
     artifacts = PROTOBUF_MAVEN_ARTIFACTS,
     repositories = [
         "https://repo1.maven.org/maven2",

java/util/BUILD.bazel

@@ -14,11 +14,11 @@ java_library(
     visibility = ["//visibility:public"],
     deps = [
         "//java/core",
-        "@protobuf_maven//:com_google_code_findbugs_jsr305",
-        "@protobuf_maven//:com_google_code_gson_gson",
-        "@protobuf_maven//:com_google_errorprone_error_prone_annotations",
-        "@protobuf_maven//:com_google_guava_guava",
-        "@protobuf_maven//:com_google_j2objc_j2objc_annotations",
+        "@maven//:com_google_code_findbugs_jsr305",
+        "@maven//:com_google_code_gson_gson",
+        "@maven//:com_google_errorprone_error_prone_annotations",
+        "@maven//:com_google_guava_guava",
+        "@maven//:com_google_j2objc_j2objc_annotations",
     ],
 )
 
@@ -34,11 +34,11 @@ protobuf_versioned_java_library(
     visibility = ["//visibility:public"],
     deps = [
         "//java/core",
-        "@protobuf_maven//:com_google_code_findbugs_jsr305",
-        "@protobuf_maven//:com_google_code_gson_gson",
-        "@protobuf_maven//:com_google_errorprone_error_prone_annotations",
-        "@protobuf_maven//:com_google_guava_guava",
-        "@protobuf_maven//:com_google_j2objc_j2objc_annotations",
+        "@maven//:com_google_code_findbugs_jsr305",
+        "@maven//:com_google_code_gson_gson",
+        "@maven//:com_google_errorprone_error_prone_annotations",
+        "@maven//:com_google_guava_guava",
+        "@maven//:com_google_j2objc_j2objc_annotations",
     ],
 )