BAEL-9013 Add code for intro to spring grpc

pom.xml

@@ -794,6 +794,7 @@
                 <module>spring-drools</module>
                 <module>spring-ejb-modules</module>
                 <module>spring-exceptions</module>
+                <module>spring-grpc</module>
                 <module>spring-jersey</module>
                 <module>spring-kafka</module>
                 <module>spring-kafka-2</module>
@@ -1226,6 +1227,7 @@
                 <module>spring-drools</module>
                 <module>spring-ejb-modules</module>
                 <module>spring-exceptions</module>
+                <module>spring-grpc</module>
                 <module>spring-jersey</module>
                 <module>spring-kafka</module>
                 <module>spring-kafka-2</module>

spring-grpc/README.md

@@ -0,0 +1,3 @@
+## Spring Protocol Buffers
+
+This module contains articles about Spring with gRPC

spring-grpc/pom.xml

@@ -0,0 +1,113 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>spring-grpc</artifactId>
+    <version>0.1-SNAPSHOT</version>
+    <name>spring-grpc</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-3</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-boot-3</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.grpc</groupId>
+            <artifactId>grpc-services</artifactId>
+            <version>${grpc-services.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.grpc</groupId>
+            <artifactId>spring-grpc-spring-boot-starter</artifactId>
+            <version>${spring-grpc.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <version>${spring-boot.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.grpc</groupId>
+            <artifactId>spring-grpc-test</artifactId>
+            <version>${spring-grpc.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-core</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+        </dependency>
+    </dependencies>
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.grpc</groupId>
+                <artifactId>spring-grpc-dependencies</artifactId>
+                <version>${spring-grpc.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>kr.motd.maven</groupId>
+                <artifactId>os-maven-plugin</artifactId>
+                <version>1.7.1</version>
+                <executions>
+                    <execution>
+                        <id>initialize</id>
+                        <phase>initialize</phase>
+                        <goals>
+                            <goal>detect</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.xolstice.maven.plugins</groupId>
+                <artifactId>protobuf-maven-plugin</artifactId>
+                <version>0.6.1</version>
+                <configuration>
+                    <protocArtifact>com.google.protobuf:protoc:${protobuf-java.version}:exe:${os.detected.classifier}</protocArtifact>
+                    <pluginId>grpc-java</pluginId>
+                    <pluginArtifact>io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}</pluginArtifact>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>compile</id>
+                        <goals>
+                            <goal>compile</goal>
+                            <goal>compile-custom</goal>
+                        </goals>
+                        <configuration>
+                            <pluginParameter>jakarta_omit,@generated=omit</pluginParameter>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <java.version>17</java.version>
+        <grpc.version>1.72.0</grpc.version>
+        <protobuf-java.version>4.30.2</protobuf-java.version>
+        <spring-grpc.version>0.8.0</spring-grpc.version>
+        <grpc-services.version>1.72.0</grpc-services.version>
+        <spring-grpc.version>0.8.0</spring-grpc.version>
+        <spring-boot.version>3.4.5</spring-boot.version>
+    </properties>
+
+</project>

spring-grpc/src/main/java/com/baeldung/grpc/GrpcCalculatorService.java

@@ -0,0 +1,20 @@
+package com.baeldung.grpc;
+
+import org.springframework.stereotype.Service;
+import org.springframework.grpc.calculator.proto.CalculatorGrpc;
+import org.springframework.grpc.calculator.proto.Response;
+import org.springframework.grpc.calculator.proto.Request;
+
+import io.grpc.stub.StreamObserver;
+
+@Service
+public class GrpcCalculatorService extends CalculatorGrpc.CalculatorImplBase {
+
+    @Override
+    public void multiply(Request req, StreamObserver<Response> responseObserver) {
+        Response reply = Response.newBuilder().setResult(req.getFirstValue() * req.getSecondValue()).build();
+        responseObserver.onNext(reply);
+        responseObserver.onCompleted();
+    }
+
+}

spring-grpc/src/main/java/com/baeldung/grpc/SpringgRPCApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung.grpc;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringgRPCApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(SpringgRPCApplication.class, args);
+	}
+
+}

spring-grpc/src/main/proto/calculator.proto

@@ -0,0 +1,18 @@
+syntax = "proto3";
+
+option java_multiple_files = true;
+option java_package = "org.springframework.grpc.calculator.proto";
+option java_outer_classname = "CalculatorProto";
+
+service Calculator {
+  rpc Multiply(Request) returns (Response) {}
+}
+
+message Request {
+  int32 firstValue = 1;
+  int32 secondValue = 2;
+}
+
+message Response {
+  int32 result = 1;
+}

spring-grpc/src/main/resources/application.properties

@@ -0,0 +1 @@
+spring.application.name=Calculator