pzampino commented on a change in pull request #147: KNOX-1914 - New admin API to be used by the UI to fetch available service discovery types URL: https://github.com/apache/knox/pull/147#discussion_r327244641
########## File path: gateway-spi/src/main/java/org/apache/knox/gateway/topology/discovery/ServiceDiscoveryFactory.java ########## @@ -0,0 +1,81 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with this + * work for additional information regarding copyright ownership. The ASF + * licenses this file to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations under + * the License. + */ +package org.apache.knox.gateway.topology.discovery; + +import java.lang.reflect.Field; +import java.util.HashSet; +import java.util.ServiceLoader; +import java.util.Set; + +import org.apache.commons.lang3.ArrayUtils; +import org.apache.knox.gateway.services.Service; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Creates instances of ServiceDiscovery implementations. + * + * This factory uses the ServiceLoader mechanism to load ServiceDiscovery + * implementations as extensions. + * + */ +public abstract class ServiceDiscoveryFactory { + + private static final Logger LOG = LoggerFactory.getLogger(ServiceDiscoveryFactory.class); + + private static final Service[] NO_GATEWAY_SERVICS = new Service[] {}; + + public static ServiceDiscovery get(String type) { + return get(type, NO_GATEWAY_SERVICS); + } + + public static Set<ServiceDiscovery> getAllServiceDiscoveries() { + final Set<ServiceDiscovery> serviceDiscoveries = new HashSet<>(); + ServiceLoader.load(ServiceDiscoveryType.class).forEach((serviceDiscoveryType) -> { + serviceDiscoveries.add(serviceDiscoveryType.newInstance()); + }); + return serviceDiscoveries; + } + + public static ServiceDiscovery get(String type, Service... gatewayServices) { + final ServiceDiscovery sd = getAllServiceDiscoveries().stream().filter(serviceDiscovery -> serviceDiscovery.getType().equalsIgnoreCase(type)).findFirst().orElse(null); Review comment: I would prefer an exception different than a NPE though. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
