ProtoBufMaven.xml

   <plugin>
                <groupId>org.xolstice.maven.plugins</groupId>
                <artifactId>protobuf-maven-plugin</artifactId>
                <version>0.5.1</version>
                <configuration>
                    <protocExecutable>/usr/local/opt/protobuf/bin/protoc</protocExecutable>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>test-compile</goal>
                        </goals>
                        <configuration>
                            <protocExecutable>/usr/local/opt/protobuf/bin/protoc</protocExecutable>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

           <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>build-helper-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <id>add-protobuf-generate-sources</id>
                        <phase>generate-sources</phase>
                        <goals>
                            <goal>add-source</goal>
                        </goals>
                        <configuration>
                            <sources>
                                <source>target/generated-sources/protobuf/java</source>
                            </sources>
                        </configuration>
                    </execution>

                    <execution>
                        <id>add-protobuf-generate-test-sources</id>
                        <phase>generate-sources</phase>
                        <goals>
                            <goal>add-test-source</goal>
                        </goals>
                        <configuration>
                            <sources>
                                <source>target/generated-test-sources/protobuf/java</source>
                            </sources>
                        </configuration>
                    </execution>
                </executions>
            </plugin>