"this.simpleStub" is null

[SeanTan7150]

tmaccount

@GrpcService
public class HelloService extends SimpleGrpc.SimpleImplBase {

    private static final Logger log = LoggerFactory.getLogger(AuthenticationService.class);

    @Override
    public void sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver) {
        log.info("Hello " + req.getName());
        if (req.getName().startsWith("error")) {
            throw new IllegalArgumentException("Bad name: " + req.getName());
        }
        if (req.getName().startsWith("internal")) {
            throw new RuntimeException();
        }
        HelloReply reply = HelloReply.newBuilder().setMessage("Hello ==> " + req.getName()).build();
        responseObserver.onNext(reply);
        responseObserver.onCompleted();
    }
}

tmcore

@Service
public class HelloService {

    private static final Logger log = LoggerFactory.getLogger(AuthenticationService.class);

    @GrpcClient("tmaccount")
    private SimpleGrpc.SimpleBlockingStub simpleStub;

    public String sendMessage(String name) {
        HelloRequest request = HelloRequest.newBuilder().setName(name).build();
        HelloReply response = simpleStub.sayHello(request);
        return response.getMessage();
    }
}

tmcore application.properties

spring.application.name=tmcore
server.port=8081

# Configuration for MySQL Database
spring.jpa.hibernate.ddl-auto=update
spring.datasource.url=jdbc:mysql://localhost:3306/tmcore
spring.datasource.username=${DB_USERNAME}
spring.datasource.password=${DB_PASSWORD}
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.jpa.show-sql:true

grpc.client.tmaccount.address=static://localhost:9090
grpc.client.tmaccount.negotiationType=plaintext

When I tried to run helloService.sendMessage("demo"), it shows error below:

java.lang.NullPointerException: Cannot invoke "org.springframework.grpc.sample.proto.SimpleGrpc$SimpleBlockingStub.sayHello(org.springframework.grpc.sample.proto.HelloRequest)" because "this.simpleStub" is null

Is there any configuration I've done wrong?

[kannanjgithub]

This isn't really a gRPC specific question but about spring boot auto configuration not working. You should check for things like component base scan whether it includes the package where you are trying to use the auto-configure.