Add gRPC client sample with Spring Integration

basic/barrier/pom.xml

@@ -73,8 +73,7 @@
     </dependency>
     <dependency>
       <groupId>org.springframework.boot</groupId>
-      <artifactId>spring-boot-starter-rabbitmq</artifactId>
-      <version>4.1.0-SNAPSHOT</version>
+      <artifactId>spring-boot-starter-amqp</artifactId>
       <scope>compile</scope>
     </dependency>
     <dependency>

basic/grpc-client/README.md

@@ -0,0 +1,58 @@
+gRPC Client Sample
+==================
+
+This example demonstrates the use of Spring Integration's **gRPC Outbound Gateway** for client-side communication.
+
+It uses Java configuration and the Spring Integration DSL to configure the gRPC client adapters.
+
+The sample demonstrates two gRPC communication patterns:
+
+1. **Single Response** - Simple request/reply pattern where the client sends a request and receives a single response
+2. **Streaming Response** - The client sends a request and receives a stream of responses
+
+## Prerequisites
+
+This sample requires a gRPC server to be running. You can use any gRPC server that implements the `Simple` service defined in `hello.proto`, or run the test which uses an in-process gRPC server.
+
+## Running the sample
+
+### Command Line Using Gradle
+
+To run the sample using Gradle, execute:
+
+    $ gradlew :grpc-client:bootRun
+
+This will start the Spring Boot application using the [Spring Boot Gradle Plugin](https://docs.spring.io/spring-boot/docs/current/gradle-plugin/reference/html/).
+
+## Configuration
+
+The application expects a gRPC server to be available. By default, it connects to `localhost:9090`. You can configure the server address in `application.properties`:
+
+```properties
+spring.grpc.client.channels.spring-integration.address=static://localhost:9090
+```
+
+## Output
+
+The application demonstrates two patterns:
+
+### Single Response Pattern
+
+The client sends a `HelloRequest` with name "Jack" and receives a single `HelloReply`:
+
+    Single response reply: message: Hello Jack
+
+### Streaming Response Pattern
+
+The client sends a `HelloRequest` with name "Jane" and receives multiple `HelloReply` messages:
+
+    Stream received reply: Hello Jane
+    Stream received reply: Hello Again
+
+## Running the Tests
+
+The test uses an in-process gRPC server and does not require an external server:
+
+    $ gradlew :grpc-client:test
+
+The test validates both single-response and streaming-response patterns.