Implements support for client gRPC channel injections. Does not use C…

…DI qualifiers for forward compatibility with our declarative API (annotations will be reused). New test that shows field and constructor injection.

grpc/api/src/main/java/io/helidon/grpc/api/Grpc.java

@@ -275,7 +275,7 @@ public interface Grpc {
     }
 
     /**
-     * An annotation to indicate the response type of a gRPC method.
+     * An annotation to indicate the response type of gRPC method.
      */
     @Target(ElementType.METHOD)
     @Retention(RetentionPolicy.RUNTIME)
@@ -293,7 +293,7 @@ public interface Grpc {
     /**
      * An annotation that can be used to specify the name of a configured gRPC channel.
      */
-    @Target({ElementType.TYPE, ElementType.METHOD})
+    @Target({ElementType.TYPE, ElementType.METHOD, ElementType.CONSTRUCTOR, ElementType.FIELD, ElementType.PARAMETER})
     @Retention(RetentionPolicy.RUNTIME)
     @interface GrpcChannel {
 

microprofile/grpc/client/src/main/java/io/helidon/microprofile/grpc/client/ChannelProducer.java

@@ -57,9 +57,8 @@ public class ChannelProducer {
      * @return a gRPC {@link io.grpc.Channel}
      */
     @Produces
-    @Grpc.GrpcChannel(GrpcChannelsProvider.DEFAULT_CHANNEL_NAME)
     public Channel get(InjectionPoint injectionPoint) {
-        Grpc.GrpcChannel qualifier = injectionPoint.getQualifiers()
+        Grpc.GrpcChannel qualifier = injectionPoint.getAnnotated().getAnnotations()
                 .stream()
                 .filter(q -> q.annotationType().equals(Grpc.GrpcChannel.class))
                 .map(q -> (Grpc.GrpcChannel) q)
@@ -70,16 +69,6 @@ public Channel get(InjectionPoint injectionPoint) {
         return findChannel(name);
     }
 
-    /**
-     * Produces the default gRPC {@link io.grpc.Channel}.
-     *
-     * @return the default gRPC {@link io.grpc.Channel}
-     */
-    @Produces
-    public Channel getDefaultChannel() {
-        return findChannel(GrpcChannelsProvider.DEFAULT_CHANNEL_NAME);
-    }
-
     /**
      * Obtain the named {@link io.grpc.Channel}.
      *

microprofile/grpc/client/src/test/java/io/helidon/microprofile/grpc/client/ChannelInjectionTest.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2024 Oracle and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.helidon.microprofile.grpc.client;
+
+import io.helidon.grpc.api.Grpc;
+import io.helidon.microprofile.testing.junit5.HelidonTest;
+
+import io.grpc.Channel;
+import jakarta.inject.Inject;
+import org.junit.jupiter.api.Test;
+
+import static org.hamcrest.CoreMatchers.notNullValue;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+@HelidonTest
+class ChannelInjectionTest {
+
+    @Inject
+    @Grpc.GrpcChannel("echo-channel")
+    private Channel echoChannel1;
+
+    private final Channel echoChannel2;
+
+    @Inject
+    ChannelInjectionTest(@Grpc.GrpcChannel("echo-channel") Channel echoChannel2) {
+        this.echoChannel2 = echoChannel2;
+    }
+
+    @Test
+    void testInjection() {
+        assertThat(echoChannel1, notNullValue());
+        assertThat(echoChannel2, notNullValue());
+        assertEquals(echoChannel1.getClass(), echoChannel2.getClass());
+        assertEquals(echoChannel1.authority(), echoChannel2.authority());
+    }
+}