Package ray java jars into wheels (#6600)

java/BUILD.bazel

@@ -207,3 +207,30 @@ genrule(
     local = 1,
     tags = ["no-cache"],
 )
+
+java_binary(
+    name = "ray_dist",
+    # This rule is used to package all Ray Java code and the third-party dependencies into a
+    # fat jar file. It's not really an executable jar. So we set its `main_class` to empty.
+    main_class = "",
+    runtime_deps = [
+        "//java:org_ray_ray_api",
+        "//java:org_ray_ray_runtime",
+        "//streaming/java:org_ray_ray_streaming-api",
+        "//streaming/java:org_ray_ray_streaming-runtime",
+    ]
+)
+
+genrule(
+    name = "ray_java_pkg",
+    srcs = ["//java:ray_dist_deploy.jar"],
+    outs = ["ray_java_pkg.out"],
+    cmd = """
+        WORK_DIR=$$(pwd)
+        rm -rf $$WORK_DIR/python/ray/jars && mkdir -p $$WORK_DIR/python/ray/jars
+        cp -f $(location //java:ray_dist_deploy.jar) $$WORK_DIR/python/ray/jars/ray_dist.jar
+        echo $$(date) > $@
+    """,
+    local = 1,
+    tags = ["no-cache"],
+)

java/test.sh

@@ -21,6 +21,12 @@ echo "Linting Java code with checkstyle."
 # Thus, we add the `build_tests_only` option to avoid re-building everything.
 bazel test //java:all --test_tag_filters="checkstyle" --build_tests_only
 
+echo "Build java maven deps."
+bazel build //java:gen_maven_deps
+
+echo "Build test jar."
+bazel build //java:all_tests_deploy.jar
+
 echo "Running tests under cluster mode."
 # TODO(hchen): Ideally, we should use the following bazel command to run Java tests. However, if there're skipped tests,
 # TestNG will exit with code 2. And bazel treats it as test failure.

java/test/src/main/java/org/ray/api/test/BaseMultiLanguageTest.java

@@ -6,6 +6,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
@@ -71,9 +73,15 @@ public abstract class BaseMultiLanguageTest {
 
     String nodeManagerPort = String.valueOf(NetworkUtil.getUnusedPort());
 
-    // Start ray cluster.
+    // jars in the `ray` wheel doesn't contains test classes, so we add test classes explicitly.
+    // Since mvn test classes contains `test` in path and bazel test classes is located at a jar
+    // with `test` included in the name, we can check classpath `test` to filter out test classes.
+    String classpath = Stream.of(System.getProperty("java.class.path").split(":"))
+        .filter(s -> !s.contains(" ") && s.contains("test"))
+        .collect(Collectors.joining(":"));
     String workerOptions =
-        " -classpath " + System.getProperty("java.class.path");
+        " -classpath " + classpath;
+    // Start ray cluster.
     List<String> startCommand = ImmutableList.of(
         "ray",
         "start",