Add protobuf-java dependency, and explicitly declare those deps wit…

…h TODOs for relevant tickets.

3rdparty/jvm/com/google/protobuf/BUILD

@@ -0,0 +1,5 @@
+jvm_artifact(
+    group="com.google.protobuf",
+    artifact="protobuf-java",
+    version="3.21.0",
+)

3rdparty/jvm/default.lock

@@ -7,6 +7,7 @@
 #   "version": 1,
 #   "generated_with_requirements": [
 #     "com.google.guava:guava:31.0.1-jre,url=not_provided,jar=not_provided",
+#     "com.google.protobuf:protobuf-java:3.21.0,url=not_provided,jar=not_provided",
 #     "com.lihaoyi:acyclic_2.13:0.2.1,url=not_provided,jar=not_provided",
 #     "org.scala-lang:scala-library:2.13.8,url=not_provided,jar=not_provided",
 #     "org.scalatest:scalatest_2.13:3.2.10,url=not_provided,jar=not_provided"
@@ -165,6 +166,19 @@ serialized_bytes_length = 8781
 [[entries]]
 directDependencies = []
 dependencies = []
+file_name = "com.google.protobuf_protobuf-java_3.21.0.jar"
+
+[entries.coord]
+group = "com.google.protobuf"
+artifact = "protobuf-java"
+version = "3.21.0"
+packaging = "jar"
+[entries.file_digest]
+fingerprint = "3d6bc9e4a87f293cb434b5a95c3011f72881a8517270c231dee035b215eb61df"
+serialized_bytes_length = 1692588
+[[entries]]
+directDependencies = []
+dependencies = []
 file_name = "com.lihaoyi_acyclic_2.13_0.2.1.jar"
 
 [entries.coord]

src/jvm/org/pantsbuild/example/lib/BUILD

@@ -3,5 +3,9 @@ java_sources(
         # Resource dependencies cannot be inferred, so we must explicitly declare that we
         # depend on them.
         "src/resources/org/pantsbuild/example/lib",
+        # TODO: Protobuf dependencies are not currently inferred.
+        # see https://github.com/pantsbuild/pants/issues/14960
+        "src/jvm/org/pantsbuild/example/proto",
+        "3rdparty/jvm/com/google/protobuf",
     ],
 )

src/jvm/org/pantsbuild/example/proto/BUILD

@@ -1 +1,7 @@
-protobuf_sources(grpc=True)
+protobuf_sources(
+    dependencies=[
+        # TODO: The protobuf runtime is not automatically injected as a dependency of protobuf targets.
+        # see https://github.com/pantsbuild/pants/pull/15006.
+        "3rdparty/jvm/com/google/protobuf",
+    ],
+)