Updates signature of split method to return a Stream.

Signed-off-by: Santiago Pericas-Geertsen <santiago.pericasgeertsen@oracle.com>

examples/microprofile/grpc/src/main/java/io/helidon/examples/microprofile/grpc/StringService.java

@@ -21,31 +21,57 @@
 
 import io.helidon.grpc.api.Grpc;
 import io.helidon.grpc.core.CollectingObserver;
-import io.helidon.grpc.core.ResponseHelper;
 
 import io.grpc.stub.StreamObserver;
 import jakarta.enterprise.context.ApplicationScoped;
 
+/**
+ * An implementation of a string service.
+ */
 @Grpc.GrpcService
 @ApplicationScoped
 public class StringService {
 
+    /**
+     * Uppercase a string.
+     *
+     * @param request string message
+     * @return string message
+     */
     @Grpc.Unary("Upper")
     public Strings.StringMessage upper(Strings.StringMessage request) {
         return newMessage(request.getText().toUpperCase());
     }
 
+    /**
+     * Lowercase a string.
+     *
+     * @param request string message
+     * @return string message
+     */
     @Grpc.Unary("Lower")
     public Strings.StringMessage lower(Strings.StringMessage request) {
         return newMessage(request.getText().toLowerCase());
     }
 
+    /**
+     * Split a string using space delimiters.
+     *
+     * @param request string message
+     * @return stream of string messages
+     */
     @Grpc.ServerStreaming("Split")
-    public void split(Strings.StringMessage request, StreamObserver<Strings.StringMessage> observer) {
+    public Stream<Strings.StringMessage> split(Strings.StringMessage request) {
         String[] parts = request.getText().split(" ");
-        ResponseHelper.stream(observer, Stream.of(parts).map(this::newMessage));
+        return Stream.of(parts).map(this::newMessage);
     }
 
+    /**
+     * Join a stream of messages using spaces.
+     *
+     * @param observer stream of messages
+     * @return single message as a stream
+     */
     @Grpc.ClientStreaming("Join")
     public StreamObserver<Strings.StringMessage> join(StreamObserver<Strings.StringMessage> observer) {
         return CollectingObserver.create(

examples/microprofile/grpc/src/main/java/io/helidon/examples/microprofile/grpc/StringServiceClient.java

@@ -16,23 +16,52 @@
 
 package io.helidon.examples.microprofile.grpc;
 
+import java.util.stream.Stream;
+
 import io.helidon.grpc.api.Grpc;
 
 import io.grpc.stub.StreamObserver;
 
+/**
+ * A client for a {@link StringService}.
+ */
 @Grpc.GrpcService("StringService")
 @Grpc.GrpcChannel("string-channel")         // see application.yaml
 public interface StringServiceClient {
 
+    /**
+     * Uppercase a string.
+     *
+     * @param request string message
+     * @return string message
+     */
     @Grpc.Unary("Upper")
     Strings.StringMessage upper(Strings.StringMessage request);
 
+    /**
+     * Lowercase a string.
+     *
+     * @param request string message
+     * @return string message
+     */
     @Grpc.Unary("Lower")
     Strings.StringMessage lower(Strings.StringMessage request);
 
+    /**
+     * Split a string using space delimiters.
+     *
+     * @param request string message
+     * @return stream of string messages
+     */
     @Grpc.ServerStreaming("Split")
-    void split(Strings.StringMessage request, StreamObserver<Strings.StringMessage> observer);
+    Stream<Strings.StringMessage> split(Strings.StringMessage request);
 
+    /**
+     * Join a stream of messages using spaces.
+     *
+     * @param observer stream of messages
+     * @return single message as a stream
+     */
     @Grpc.ClientStreaming("Join")
     StreamObserver<Strings.StringMessage> join(StreamObserver<Strings.StringMessage> observer);
 }

examples/microprofile/grpc/src/main/java/io/helidon/examples/microprofile/grpc/package-info.java

@@ -13,4 +13,4 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package io.helidon.examples.microprofile.grpc;
+package io.helidon.examples.microprofile.grpc;

examples/microprofile/grpc/src/test/java/io/helidon/examples/microprofile/grpc/StringServiceTest.java

@@ -19,6 +19,7 @@
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.stream.Stream;
 
 import io.helidon.grpc.api.Grpc;
 import io.helidon.microprofile.grpc.client.GrpcClientCdiExtension;
@@ -57,10 +58,9 @@ void testUnaryLower() {
     }
 
     @Test
-    void testServerStreamingSplit() throws InterruptedException {
-        ListObserver<Strings.StringMessage> response = new ListObserver<>();
-        client.split(newMessage("hello world"), response);
-        List<Strings.StringMessage> value = response.value();
+    void testServerStreamingSplit() {
+        Stream<Strings.StringMessage> stream = client.split(newMessage("hello world"));
+        List<Strings.StringMessage> value = stream.toList();
         assertThat(value, hasSize(2));
         assertThat(value, contains(newMessage("hello"), newMessage("world")));
     }