io.csar.DecoratedConcernedThreadGroup Maven / Gradle / Ivy

Go to download
/*
 * Copyright © 2009 GlobalMentor, 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
 *
 *     https://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.csar;

import static java.util.Objects.*;

import java.util.Optional;

/**
 * A thread group that allows the retrieval of a concern on a per-thread-group basis by decorating an existing concerned object.
 * @author Garret Wilson
 * @see Csar
 */
public class DecoratedConcernedThreadGroup extends ThreadGroup implements Concerned {

	/** The implementation for managing concerns for this thread group. */
	private final Concerned concerned;

	/** @return The implementation for managing concerns for this thread group. */
	protected Concerned getConcerned() {
		return concerned;
	}

	/**
	 * Thread group name constructor. Creates a thread group using the current thread as the parent.
	 * @param name The name of the new thread group.
	 * @param concerned The implementation for retrieving concerns for this thread group.
	 * @throws NullPointerException if the given concerned is null.
	 * @throws SecurityException If the current thread cannot create a thread in the specified thread group.
	 * @see ThreadGroup#checkAccess()
	 * @see ConcernRegistry#registerConcern(Concern)
	 */
	public DecoratedConcernedThreadGroup(final String name, final Concerned concerned) {
		this(Thread.currentThread().getThreadGroup(), name, concerned);
	}

	/**
	 * Thread group parent and thread group name constructor.
	 * @param parent The parent thread group.
	 * @param name The name of the new thread group.
	 * @param concerned The implementation for retrieving concerns for this thread group.
	 * @throws NullPointerException if the given parent and/or concerned is null.
	 * @throws SecurityException If the current thread cannot create a thread in the specified thread group.
	 * @see ThreadGroup#checkAccess()
	 * @see ConcernRegistry#registerConcern(Concern)
	 */
	public DecoratedConcernedThreadGroup(final ThreadGroup parent, final String name, final Concerned concerned) {
		super(parent, name);
		this.concerned = requireNonNull(concerned, "Concerned implementation cannot be null.");
	}

	@Override
	public  Optional findConcern(final Class concernClass) {
		return getConcerned().findConcern(concernClass);
	}

}