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/* * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.controller.md.sal.binding.spi; import com.google.common.base.Optional; import com.google.common.cache.CacheLoader; import javax.annotation.Nonnull; import javax.annotation.Nullable; public abstract class AdapterLoader<T, D> extends CacheLoader<Class<? extends T>, Optional<T>> { @Override public Optional<T> load(final Class<? extends T> key) { final AdapterBuilder<? extends T, D> builder = createBuilder(key); for (final Class<? extends D> reqDeleg : builder.getRequiredDelegates()) { final D deleg = getDelegate(reqDeleg); if (deleg != null) { builder.addDelegate(reqDeleg, deleg); } else { return Optional.absent(); } } return Optional.<T>of(builder.build()); } @Nullable protected abstract D getDelegate(Class<? extends D> reqDeleg); @Nonnull protected abstract AdapterBuilder<? extends T, D> createBuilder(Class<? extends T> key); }