ERROR: PROTOC FAILED: google/protobuf/wrappers.proto: File not found. (Error in Maven build)

Question

I was trying to build a grpc service using the following plugin. Seems like the plugin is not able to use protoc utility.

OS : MAC

Maven version : 3.6.3

Error :

[ERROR] PROTOC FAILED: google/protobuf/wrappers.proto: File not found.
order-mgmt.proto: Import "google/protobuf/wrappers.proto" was not found or had errors.
order-mgmt.proto:7:16: "google.protobuf.StringValue" is not defined.

...
**[ERROR] Failed to execute goal org.xolstice.maven.plugins:protobuf-maven-plugin:0.6.1:compile (default) on project OrderManagement-gRPC: protoc did not exit cleanly. Review output for more information. -> [Help 1]**

The plugin i am using is :

<plugin>
            <groupId>org.xolstice.maven.plugins</groupId>
            <artifactId>protobuf-maven-plugin</artifactId>
            <version>0.6.1</version>
            <configuration>
                <!--suppress UnresolvedMavenProperty -->
                <protocArtifact>com.google.protobuf:protoc:${protoc.version}:exe:${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>
                    <goals>
                        <goal>compile</goal>
                        <goal>compile-custom</goal>
                    </goals>
                </execution>
            </executions>

Answer 1

You are missing the protobuf-java dependency.

<dependencies>
    <dependency>
      <groupId>com.google.protobuf</groupId>
      <artifactId>protobuf-java</artifactId>
      <version>3.5.1-1</version>
    </dependency>
    ...
  </dependencies>

Here is how I use the plugin.

<build>
  <extensions>
    <extension>
      <groupId>kr.motd.maven</groupId>
      <artifactId>os-maven-plugin</artifactId>
      <version>1.5.0.Final</version>
    </extension>
  </extensions>
  <plugins>
    <plugin>
      <groupId>org.xolstice.maven.plugins</groupId>
      <artifactId>protobuf-maven-plugin</artifactId>
      <version>0.5.1</version>
      <extensions>true</extensions>
      <configuration>
        <protocArtifact>com.google.protobuf:protoc:3.5.1-1:exe:${os.detected.classifier}</protocArtifact>
      </configuration>
      <executions>
        <execution>
          <goals>
            <goal>compile</goal>
            <goal>test-compile</goal>
          </goals>
        </execution>
      </executions>
    </plugin>
  </plugins>
</build>

Then use the mvn protobuf:compile to generate the stubs. The reference is from the plugin repo at https://github.com/xolstice/protobuf-maven-plugin