gRPC Client Implementation

all/pom.xml

@@ -978,6 +978,10 @@
             <groupId>io.helidon.webclient</groupId>
             <artifactId>helidon-webclient-websocket</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.helidon.webclient</groupId>
+            <artifactId>helidon-webclient-grpc</artifactId>
+        </dependency>
         <dependency>
             <groupId>io.helidon.webclient</groupId>
             <artifactId>helidon-webclient-sse</artifactId>

bom/pom.xml

@@ -94,6 +94,12 @@
                 <artifactId>helidon-microprofile-graphql-server</artifactId>
                 <version>${helidon.version}</version>
             </dependency>
+            <!-- GRPC -->
+            <dependency>
+                <groupId>io.helidon.grpc</groupId>
+                <artifactId>helidon-grpc-core</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
             <!-- Micronaut integrations -->
             <dependency>
                 <groupId>io.helidon.integrations.micronaut</groupId>
@@ -1257,6 +1263,11 @@
                 <artifactId>helidon-webserver-testing-junit5-websocket</artifactId>
                 <version>${helidon.version}</version>
             </dependency>
+            <dependency>
+                <groupId>io.helidon.webserver.testing.junit5</groupId>
+                <artifactId>helidon-webserver-testing-junit5-grpc</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
             <dependency>
                 <groupId>io.helidon.webclient</groupId>
                 <artifactId>helidon-webclient-api</artifactId>
@@ -1282,6 +1293,11 @@
                 <artifactId>helidon-webclient-websocket</artifactId>
                 <version>${helidon.version}</version>
             </dependency>
+            <dependency>
+                <groupId>io.helidon.webclient</groupId>
+                <artifactId>helidon-webclient-grpc</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
             <dependency>
                 <groupId>io.helidon.webclient</groupId>
                 <artifactId>helidon-webclient-sse</artifactId>

examples/webserver/protocols/src/main/java/io/helidon/examples/webserver/protocols/ProtocolsMain.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, 2023 Oracle and/or its affiliates.
+ * Copyright (c) 2022, 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.

examples/webserver/protocols/src/main/resources/logging.properties

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2022, 2023 Oracle and/or its affiliates.
+# Copyright (c) 2022, 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.

grpc/core/pom.xml

@@ -0,0 +1,69 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+    Copyright (c) 2018, 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.
+  -->
+
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>helidon-grpc-project</artifactId>
+        <groupId>io.helidon.grpc</groupId>
+        <version>4.0.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>helidon-grpc-core</artifactId>
+    <name>Helidon gRPC related modules</name>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.helidon.common</groupId>
+            <artifactId>helidon-common</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.grpc</groupId>
+            <artifactId>grpc-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.grpc</groupId>
+            <artifactId>grpc-protobuf</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.google.protobuf</groupId>
+            <artifactId>protobuf-java</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.grpc</groupId>
+            <artifactId>grpc-stub</artifactId>
+            <exclusions>
+                <exclusion>
+                    <groupId>com.google.j2objc</groupId>
+                    <artifactId>j2objc-annotations</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-all</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

grpc/core/src/main/java/io/helidon/grpc/core/DefaultMarshallerSupplier.java

@@ -0,0 +1,45 @@
+/*
+ * 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.grpc.core;
+
+import com.google.protobuf.MessageLite;
+import io.grpc.MethodDescriptor;
+
+/**
+ * The default {@link MarshallerSupplier}.
+ */
+class DefaultMarshallerSupplier implements MarshallerSupplier {
+
+    private DefaultMarshallerSupplier() {
+    }
+
+    static DefaultMarshallerSupplier create() {
+        return new DefaultMarshallerSupplier();
+    }
+
+    private final ProtoMarshallerSupplier proto = ProtoMarshallerSupplier.create();
+
+    @Override
+    public <T> MethodDescriptor.Marshaller<T> get(Class<T> clazz) {
+        if (MessageLite.class.isAssignableFrom(clazz)) {
+            return proto.get(clazz);
+        }
+        String msg = String.format(
+                "Class %s must be a valid ProtoBuf message, or a custom marshaller for it must be specified explicitly",
+                clazz.getName());
+        throw new IllegalArgumentException(msg);
+    }
+}

grpc/core/src/main/java/io/helidon/grpc/core/InterceptorWeights.java

@@ -0,0 +1,63 @@
+/*
+ * 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.grpc.core;
+
+/**
+ * gRPC interceptor weight classes. Higher weight means higher priority.
+ */
+public class InterceptorWeights {
+
+    /**
+     * Context weight.
+     * <p>
+     * Interceptors with this weight typically <b>only</b> perform tasks
+     * such as adding state to the call {@link io.grpc.Context}.
+     */
+    public static final int CONTEXT = 5000;
+
+    /**
+     * Tracing weight.
+     * <p>
+     * Tracing and metrics interceptors are typically applied after any context
+     * interceptors so that they can trace and gather metrics on the whole call
+     * stack of remaining interceptors.
+     */
+    public static final int TRACING = CONTEXT + 1;
+
+    /**
+     * Security authentication weight.
+     */
+    public static final int AUTHENTICATION = 2000;
+
+    /**
+     * Security authorization weight.
+     */
+    public static final int AUTHORIZATION = 2000;
+
+    /**
+     * User-level weight.
+     * <p>
+     * This value is also used as a default weight for application-supplied interceptors.
+     */
+    public static final int USER = 1000;
+
+    /**
+     * Cannot create instances.
+     */
+    private InterceptorWeights() {
+    }
+}

grpc/core/src/main/java/io/helidon/grpc/core/MarshallerSupplier.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2019, 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.grpc.core;
+
+import io.grpc.MethodDescriptor;
+
+/**
+ * A supplier of {@link MethodDescriptor.Marshaller} instances for specific
+ * classes.
+ */
+@FunctionalInterface
+public interface MarshallerSupplier {
+
+    /**
+     * Obtain a {@link MethodDescriptor.Marshaller} for a type.
+     *
+     * @param clazz the {@link Class} of the type to obtain the {@link MethodDescriptor.Marshaller} for
+     * @param <T> the type to be marshalled
+     * @return a {@link MethodDescriptor.Marshaller} for a type
+     */
+    <T> MethodDescriptor.Marshaller<T> get(Class<T> clazz);
+
+    /**
+     * Creates a default marshaller supplier.
+     *
+     * @return the default marshaller supplier
+     */
+    static MarshallerSupplier create() {
+        return DefaultMarshallerSupplier.create();
+    }
+}