Source:
public <Q, R> CompletableFuture<QueryResponseMessage<R>> query(QueryMessage<Q, R> queryMessage) { QueryMessage<Q, R> interceptedQuery = dispatchInterceptors.intercept(queryMessage); CompletableFuture<QueryResponseMessage<R>> completableFuture = new CompletableFuture<>(); try { queryServiceStub() .query(serializer.serializeRequest(interceptedQuery, 1, TimeUnit.HOURS.toMillis(1), priorityCalculator.determinePriority(interceptedQuery)), new StreamObserver<QueryResponse>() { @Override public void onNext(QueryResponse queryResponse) { logger.debug("Received response: {}", queryResponse); if (queryResponse.hasErrorMessage()) { AxonServerRemoteQueryHandlingException exception = new AxonServerRemoteQueryHandlingException( queryResponse.getErrorCode(), queryResponse.getErrorMessage() ); completableFuture.completeExceptionally(exception); } else { completableFuture.complete(serializer.deserializeResponse(queryResponse)); } } @Override public void onError(Throwable throwable) { logger.warn("Received error while waiting for first response: {}", throwable.getMessage(), throwable); completableFuture.completeExceptionally(new AxonServerQueryDispatchException( ErrorCode.QUERY_DISPATCH_ERROR.errorCode(), ExceptionSerializer.serialize(configuration.getClientId(), throwable) )); } @Override public void onCompleted() { if (!completableFuture.isDone()) { completableFuture.completeExceptionally(new AxonServerQueryDispatchException( ErrorCode.QUERY_DISPATCH_ERROR.errorCode(), ErrorMessage.newBuilder() .setMessage("No result from query executor") .build() )); } } }); } catch (Exception e) { logger.warn("There was a problem issuing a query {}.", interceptedQuery, e); ErrorMessage errorMessage = ExceptionSerializer.serialize(configuration.getClientId(), e); completableFuture.completeExceptionally( new AxonServerQueryDispatchException(ErrorCode.QUERY_DISPATCH_ERROR.errorCode(), errorMessage) ); } return completableFuture; }

Target:
public <Q, R> CompletableFuture<QueryResponseMessage<R>> query(QueryMessage<Q, R> queryMessage) { QueryMessage<Q, R> interceptedQuery = dispatchInterceptors.intercept(queryMessage); CompletableFuture<QueryResponseMessage<R>> completableFuture = new CompletableFuture<>(); try { queryServiceStub() .query(serializer.serializeRequest(interceptedQuery, 1, TimeUnit.HOURS.toMillis(1), priorityCalculator.determinePriority(interceptedQuery)), new StreamObserver<QueryResponse>() { @Override public void onNext(QueryResponse queryResponse) { logger.debug("Received response: {}", queryResponse); if (queryResponse.hasErrorMessage()) { AxonServerRemoteQueryHandlingException exception = new AxonServerRemoteQueryHandlingException( queryResponse.getErrorCode(), queryResponse.getErrorMessage() ); completableFuture.completeExceptionally(exception); } else { completableFuture.complete(serializer.deserializeResponse(queryResponse)); } } @Override public void onError(Throwable throwable) { logger.warn("Received error while waiting for first response: {}", throwable.getMessage(), throwable); completableFuture.completeExceptionally(new AxonServerQueryDispatchException( ErrorCode.QUERY_DISPATCH_ERROR.errorCode(), ExceptionSerializer.serialize(configuration.getClientId(), throwable) )); } @Override public void onCompleted() { if (!completableFuture.isDone()) { completableFuture.completeExceptionally(new AxonServerQueryDispatchException( ErrorCode.QUERY_DISPATCH_ERROR.errorCode(), ErrorMessage.newBuilder() .setMessage("No result from query executor") .build() )); } } }); } catch (Exception e) { logger.warn("There was a problem issuing a query {}.", interceptedQuery, e); completableFuture.completeExceptionally( ErrorCode.QUERY_DISPATCH_ERROR.convert(configuration.getClientId(), e) ); } return completableFuture; }