Here is my accounts.protobuf file

package com.lyngo.account.protobuf;

syntax = "proto3";

import "google/protobuf/empty.proto";

service GrpcAccountService {
rpc loginWithEmailPassword(EmailPasswordAuthentication) returns (google.protobuf.Empty);

message EmailPasswordAuthentication {
required string email = 1;
required string password = 2;
}

Here is error after trying to generate the class from protobuf file

[ERROR] PROTOC FAILED: accounts.proto:3:1: Expected top-level statement (e.g. "message").

[ERROR] E:\Programming\1 book-store\account-service\src\main\proto\accounts.proto [0:0]: accounts.proto:3:1: Expected top-level statement (e.g. "message").

After searching, I see that error will appear if I declare the message in a wrong way. But it points to the line where I declare the protobuf syntax version.

Here are some dependencies and plugins in case you need it:

<dependency>
    <groupId>net.devh</groupId>
    <artifactId>grpc-server-spring-boot-starter</artifactId>
    <version>3.1.0.RELEASE</version>
</dependency>
<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-stub</artifactId>
    <version>1.70.0</version>
</dependency>
<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-protobuf</artifactId>
    <version>1.70.0</version>
</dependency>

<plugin>
    <groupId>io.grpc</groupId>
    <artifactId>protoc-gen-grpc-java</artifactId>
    <version>1.70.0</version>
</plugin>
<plugin>
    <groupId>com.google.protobuf</groupId>
    <artifactId>protoc</artifactId>
    <version>4.29.3</version>
</plugin>
<plugin>
    <groupId>.xolstice.maven.plugins</groupId>
    <artifactId>protobuf-maven-plugin</artifactId>
    <version>0.6.1</version>
    <configuration>
        <protocArtifact>com.google.protobuf:protoc:4.29.3:exe:${os.detected.classifier}</protocArtifact>
        <pluginId>grpc-java</pluginId>
        <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.70.0:exe:${os.detected.classifier}</pluginArtifact>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>compile</goal>
                <goal>compile-custom</goal>
                <goal>test-compile</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Could you please help me to find a solution for this?

Here is my accounts.protobuf file

package com.lyngo.account.protobuf;

syntax = "proto3";

import "google/protobuf/empty.proto";

service GrpcAccountService {
rpc loginWithEmailPassword(EmailPasswordAuthentication) returns (google.protobuf.Empty);

message EmailPasswordAuthentication {
required string email = 1;
required string password = 2;
}

Here is error after trying to generate the class from protobuf file

[ERROR] PROTOC FAILED: accounts.proto:3:1: Expected top-level statement (e.g. "message").

[ERROR] E:\Programming\1 book-store\account-service\src\main\proto\accounts.proto [0:0]: accounts.proto:3:1: Expected top-level statement (e.g. "message").

After searching, I see that error will appear if I declare the message in a wrong way. But it points to the line where I declare the protobuf syntax version.

Here are some dependencies and plugins in case you need it:

<dependency>
    <groupId>net.devh</groupId>
    <artifactId>grpc-server-spring-boot-starter</artifactId>
    <version>3.1.0.RELEASE</version>
</dependency>
<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-stub</artifactId>
    <version>1.70.0</version>
</dependency>
<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-protobuf</artifactId>
    <version>1.70.0</version>
</dependency>

<plugin>
    <groupId>io.grpc</groupId>
    <artifactId>protoc-gen-grpc-java</artifactId>
    <version>1.70.0</version>
</plugin>
<plugin>
    <groupId>com.google.protobuf</groupId>
    <artifactId>protoc</artifactId>
    <version>4.29.3</version>
</plugin>
<plugin>
    <groupId>.xolstice.maven.plugins</groupId>
    <artifactId>protobuf-maven-plugin</artifactId>
    <version>0.6.1</version>
    <configuration>
        <protocArtifact>com.google.protobuf:protoc:4.29.3:exe:${os.detected.classifier}</protocArtifact>
        <pluginId>grpc-java</pluginId>
        <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.70.0:exe:${os.detected.classifier}</pluginArtifact>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>compile</goal>
                <goal>compile-custom</goal>
                <goal>test-compile</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Could you please help me to find a solution for this?

• java
• spring-boot
• protocol-buffers
• grpc
• grpc-java

1 Answer 1

Try:

package com.lyngo.account.protobuf;

import "google/protobuf/empty.proto";

service GrpcAccountService {
    rpc loginWithEmailPassword(EmailPasswordAuthentication) returns (google.protobuf.Empty);
}

message EmailPasswordAuthentication {
    required string email = 1;
    required string password = 2;
}

The schema is well-documented on Protobuf.

syntax (if used) must be the first statement.

required is permitted with syntax = "proto2"; and the new editions