[java] add the LICENSE and NOTICE files to the jars created

BUILD.bazel

@@ -23,6 +23,20 @@ filegroup(
     visibility = ["//visibility:public"],
 )
 
+genrule(
+    name = "legal-stuff",
+    srcs = [
+        "//:LICENSE",
+        "//:NOTICE",
+    ],
+    outs = [
+        "META-INF/LICENSE",
+        "META-INF/NOTICE",
+    ],
+    cmd = "cp $(location //:LICENSE) $(location META-INF/LICENSE) && cp $(location //:NOTICE) $(location META-INF/NOTICE)",
+    visibility = ["//visibility:public"],
+)
+
 package_metadata(
     name = "package_metadata",
     attributes = [

java/defs.bzl

@@ -4,11 +4,11 @@ load(
 )
 load(
     "@rules_java//java:defs.bzl",
-    _java_binary = "java_binary",
     _java_import = "java_import",
 )
 load("@rules_jvm_external//:defs.bzl", _artifact = "artifact", _javadoc = "javadoc", _maven_bom = "maven_bom")
 load("//java/private:dist_zip.bzl", _java_dist_zip = "java_dist_zip")
+load("//java/private:java_binary.bzl", _java_binary = "java_binary")
 load("//java/private:java_test_suite.bzl", _java_test_suite = "java_test_suite")
 load("//java/private:library.bzl", _java_export = "java_export", _java_library = "java_library", _java_test = "java_test")
 load("//java/private:merge_jars.bzl", _merge_jars = "merge_jars")

java/private/java_binary.bzl

@@ -0,0 +1,14 @@
+load(
+    "@contrib_rules_jvm//java:defs.bzl",
+    _java_binary = "java_binary",
+)
+
+def java_binary(name, deps = [], srcs = [], data = [], resources = [], **kwargs):
+    _java_binary(
+        name = name,
+        deps = deps,
+        srcs = srcs,
+        data = data,
+        resources = resources + ["//:legal-stuff"],
+        **kwargs
+    )

java/private/java_library.bzl

@@ -7,6 +7,7 @@ def java_library(
         name,
         deps = [],
         srcs = [],
+        resources = [],
         exports = [],
         tags = [],
         visibility = None,
@@ -40,6 +41,7 @@ def java_library(
         name = name,
         deps = deps,
         srcs = srcs,
+        resources = resources + ["//:legal-stuff"],
         exports = exports,
         tags = tags,
         visibility = visibility,

java/private/merge_jars.bzl

@@ -5,6 +5,9 @@ def _merge_jars_impl(ctx):
     args.add("--output", out)
     args.add_all(ctx.files.inputs, before_each = "--sources")
 
+    # ensure we include all files the license of the different project we merge might require
+    args.add("--allow-duplicate", ".*(COPYRIGHT|LEGAL|LICENSE|PRIVACY|NOTICE).*")
+
     ctx.actions.run(
         mnemonic = "MergeJars",
         executable = ctx.executable._merge_jars,