io.fabric8.kubernetes.client.Handlers Maven / Gradle / Ivy

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/**
 * Copyright (C) 2015 Red Hat, Inc.
 *
 * Licensed 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 io.fabric8.kubernetes.client;

import io.fabric8.kubernetes.api.builder.VisitableBuilder;
import io.fabric8.kubernetes.api.model.HasMetadata;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.ServiceLoader;
import java.util.Set;

public final class Handlers {

  private static final Set CLASS_LOADERS = new HashSet<>();
  private static final Map RESOURCE_HANDLER_MAP = new HashMap<>();

  private Handlers() {
    //Utility
  }

  static {
    //Register handlers
    discoverHandlers(ResourceHandler.class.getClassLoader());
  }

  public static > void register(ResourceHandler handler) {
    RESOURCE_HANDLER_MAP.put(handler.getKind().toLowerCase(), handler);
  }

  public static > void unregister(ResourceHandler handler) {
    RESOURCE_HANDLER_MAP.remove(handler.getKind().toLowerCase());
  }

  public static > ResourceHandler get(String kind) {
    if (RESOURCE_HANDLER_MAP.containsKey(kind.toLowerCase())) {
      return RESOURCE_HANDLER_MAP.get(kind.toLowerCase());
    } else {
      for (ResourceHandler handler : ServiceLoader.load(ResourceHandler.class, Thread.currentThread().getContextClassLoader())) {
        if (handler.getKind().equals(kind)) {
          return handler;
        }
      }
      return null;
    }
  }

  private static void discoverHandlers(ClassLoader classLoader) {
    if (classLoader != null && CLASS_LOADERS.add(classLoader)) {
      for (ResourceHandler handler : ServiceLoader.load(ResourceHandler.class, classLoader)) {
        register(handler);
      }
    }
  }
}