Health.java

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package grpc.health.v1;

import grpc.health.v1.HealthOuterClass.HealthCheckRequest;
import grpc.health.v1.HealthOuterClass.HealthCheckResponse;
import grpc.health.v1.HealthOuterClass.HealthCheckResponse.ServingStatus;
import io.grpc.Status;
import io.grpc.StatusException;
import io.grpc.stub.StreamObserver;
import java.util.logging.Logger;

/** gRPC Health Checking Protocol */
public class Health {
  private static final Logger logger = Logger.getLogger(Health.class.getName());
  private static final String ACCEPTED_SERVICE = "ext.maps.booking.partner.v2.BookingService";

  /** The implementation of Health Checking Service. */
  public static class HealthImpl extends HealthGrpc.HealthImplBase {
    @Override
    public void check(
        HealthCheckRequest request, StreamObserver<HealthCheckResponse> responseObserver) {
      String service = request.getService();
      if (!service.equals(ACCEPTED_SERVICE)) {
        responseObserver.onError(
            new StatusException(Status.NOT_FOUND.withDescription("Unknown service")));
      } else {
        HealthCheckResponse response =
            HealthCheckResponse.newBuilder().setStatus(getServingStatus()).build();
        responseObserver.onNext(response);
        responseObserver.onCompleted();
      }
    }

    private ServingStatus getServingStatus() {
      // TODO(partner): check the health status of the service
      //
      // ServingStatus status = ... (e.g. ServingStatus.SERVING)
      // return status;

      throw new UnsupportedOperationException("Not implemented yet");
    }
  }
}