Add basic GrpcChannelFactory implementation

samples/grpc-server/src/test/java/org/springframework/grpc/sample/GrpcServerApplicationTests.java

@@ -10,15 +10,12 @@ import org.springframework.boot.SpringApplication;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.TestConfiguration;
 import org.springframework.context.annotation.Bean;
+import org.springframework.grpc.client.GrpcChannelFactory;
 import org.springframework.grpc.sample.proto.HelloReply;
 import org.springframework.grpc.sample.proto.HelloRequest;
 import org.springframework.grpc.sample.proto.SimpleGrpc;
 import org.springframework.test.annotation.DirtiesContext;
 
-import io.grpc.Channel;
-import io.grpc.Grpc;
-import io.grpc.InsecureChannelCredentials;
-
 @SpringBootTest
 public class GrpcServerApplicationTests {
 
@@ -48,13 +45,8 @@ public class GrpcServerApplicationTests {
 	static class ExtraConfiguration {
 
 		@Bean
-		SimpleGrpc.SimpleBlockingStub stub(Channel channel) {
-			return SimpleGrpc.newBlockingStub(channel);
-		}
-
-		@Bean(destroyMethod = "shutdown")
-		Channel channel() {
-			return Grpc.newChannelBuilderForAddress("0.0.0.0", 9090, InsecureChannelCredentials.create()).build();
+		SimpleGrpc.SimpleBlockingStub stub(GrpcChannelFactory channels) {
+			return SimpleGrpc.newBlockingStub(channels.createChannel("0.0.0.0:9090").build());
 		}
 
 	}

spring-grpc-core/src/main/java/org/springframework/grpc/client/DefaultGrpcChannelFactory.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2024-2024 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 org.springframework.grpc.client;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+import org.springframework.beans.factory.DisposableBean;
+
+import io.grpc.ForwardingChannelBuilder2;
+import io.grpc.Grpc;
+import io.grpc.InsecureChannelCredentials;
+import io.grpc.ManagedChannel;
+import io.grpc.ManagedChannelBuilder;
+
+public class DefaultGrpcChannelFactory implements GrpcChannelFactory, DisposableBean {
+
+	private Collection<ManagedChannel> channels = new ArrayList<>();
+
+	@Override
+	public ManagedChannelBuilder<?> createChannel(String authority) {
+		ManagedChannelBuilder<?> target = Grpc.newChannelBuilder(authority, InsecureChannelCredentials.create());
+		return new DisposableChannelBuilder(target);
+	}
+
+	@Override
+	public void destroy() throws Exception {
+		for (ManagedChannel channel : channels) {
+			channel.shutdown();
+		}
+	}
+
+	class DisposableChannelBuilder extends ForwardingChannelBuilder2<DisposableChannelBuilder> {
+
+		private final ManagedChannelBuilder<?> delegate;
+
+		public DisposableChannelBuilder(ManagedChannelBuilder<?> delegate) {
+			this.delegate = delegate;
+		}
+
+		@Override
+		protected ManagedChannelBuilder<?> delegate() {
+			return delegate;
+		}
+
+		@Override
+		public ManagedChannel build() {
+			ManagedChannel channel = super.build();
+			channels.add(channel);
+			return channel;
+		}
+
+	}
+
+}

spring-grpc-core/src/main/java/org/springframework/grpc/client/GrpcChannelFactory.java

@@ -15,10 +15,10 @@
  */
 package org.springframework.grpc.client;
 
-import io.grpc.Channel;
+import io.grpc.ManagedChannelBuilder;
 
-public interface GrpcChannelFactory extends AutoCloseable {
+public interface GrpcChannelFactory {
 
-	Channel createChannel(String name);
+	ManagedChannelBuilder<?> createChannel(String authority);
 
 }

spring-grpc-spring-boot-autoconfigure/src/main/java/org/springframework/grpc/autoconfigure/client/GrpcClientAutoConfiguration.java

@@ -15,12 +15,19 @@
  */
 package org.springframework.grpc.autoconfigure.client;
 
-import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.grpc.server.GrpcServerFactory;
+import org.springframework.grpc.client.DefaultGrpcChannelFactory;
+import org.springframework.grpc.client.GrpcChannelFactory;
 
 @Configuration(proxyBeanMethods = false)
-@ConditionalOnBean(GrpcServerFactory.class)
 public class GrpcClientAutoConfiguration {
 
+	@Bean
+	@ConditionalOnMissingBean(GrpcChannelFactory.class)
+	public DefaultGrpcChannelFactory defaultGrpcChannelFactory() {
+		return new DefaultGrpcChannelFactory();
+	}
+
 }

spring-grpc-spring-boot-autoconfigure/src/main/resources/META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports

@@ -1,2 +1,3 @@
 org.springframework.grpc.autoconfigure.server.GrpcServiceAutoConfiguration
 org.springframework.grpc.autoconfigure.server.GrpcServerFactoryAutoConfiguration
+org.springframework.grpc.autoconfigure.client.GrpcClientAutoConfiguration