2 * Copyright (c) 2019-2020. Developed by Hedgecode.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 package org.hedgecode.chess.scanner.spi;
19 import java.util.Iterator;
20 import java.util.ServiceLoader;
23 * Service Provider Interface (SPI) Registry.
25 * @author Dmitry Samoshin aka gotty
27 public final class ServiceRegistry {
29 private ServiceRegistry() {
32 public static <ServiceType> ServiceType singleProvider(Class<ServiceType> serviceClass) {
33 final Iterator<ServiceType> providers = providers(serviceClass);
35 ServiceType provider = providers.next();
36 if (providers.hasNext()) {
37 throw new ServiceRegistryException(
38 String.format("Too many service providers for: %s", serviceClass.getName())
45 private static <ServiceType> Iterator<ServiceType> providers(Class<ServiceType> serviceClass) {
46 final Iterator<ServiceType> providers = ServiceLoader.load(serviceClass).iterator();
48 if (!providers.hasNext()) {
49 throw new ServiceRegistryException(
50 String.format("Service provider not found for: %s", serviceClass.getName())