如何在Java GRPC中配置.proto路径？

<build>
  <plugins>
    <plugin>
      <groupId>org.xolstice.maven.plugins</groupId>
      <artifactId>protobuf-maven-plugin</artifactId>
      <version>0.6.1</version>
      <configuration>
        <protocArtifact>com.google.protobuf:protoc:3.17.3:exe:${os.detected.classifier}</protocArtifact>
        <pluginId>grpc-java</pluginId>
        <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.41.0:exe:${os.detected.classifier}</pluginArtifact>
      </configuration>
      <executions>
        <execution>
          <goals>
            <goal>compile</goal>
            <goal>compile-custom</goal>
          </goals>
        </execution>
      </executions>
    </plugin>
  </plugins>
</build>

<dependencies>
  <dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-netty</artifactId>
    <version>1.41.0</version>
  </dependency>
  <dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-protobuf</artifactId>
    <version>1.41.0</version>
  </dependency>
  <dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-stub</artifactId>
    <version>1.41.0</version>
  </dependency>
</dependencies>

protoc -I=<proto文件目录> --java_out=<生成的Java代码目录> --grpc-java_out=<生成的Java代码目录> <proto文件>

protoc -I=src/main/proto --java_out=src/main/java --grpc-java_out=src/main/java example.proto

ManagedChannel channel = ManagedChannelBuilder.forAddress("localhost", 8080)
    .usePlaintext()
    .build();

ExampleServiceGrpc.ExampleServiceBlockingStub stub = ExampleServiceGrpc.newBlockingStub(channel);