juneau-core/juneau-marshall/src/main/java/org/apache/juneau/cp/DefaultClassList.java

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// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
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// ***************************************************************************************************************************
package org.apache.juneau.cp;

import static org.apache.juneau.common.internal.ArgUtils.*;
import static org.apache.juneau.internal.CollectionUtils.*;

import java.util.*;

/**
 * A list of default implementation classes.
 *
 * <h5 class='section'>Notes:</h5><ul>
 * 	<li class='warn'>This class is not thread safe.
 * </ul>
 *
 * <h5 class='section'>See Also:</h5><ul>
 * </ul>
 */
public class DefaultClassList {

	//-----------------------------------------------------------------------------------------------------------------
	// Static
	//-----------------------------------------------------------------------------------------------------------------

	/**
	 * Static creator.
	 *
	 * @return A new object.
	 */
	public static DefaultClassList create() {
		return new DefaultClassList();
	}

	/**
	 * Static creator.
	 *
	 * @param values Initial entries in this list.
	 * @return A new object initialized with the specified values.
	 */
	public static DefaultClassList of(Class<?>...values) {
		return new DefaultClassList().add(values);
	}

	//-----------------------------------------------------------------------------------------------------------------
	// Instance
	//-----------------------------------------------------------------------------------------------------------------

	private final List<Class<?>> entries;

	/**
	 * Constructor.
	 */
	protected DefaultClassList() {
		entries = list();
	}

	/**
	 * Copy constructor
	 *
	 * @param value The object to copy.
	 */
	public DefaultClassList(DefaultClassList value) {
		entries = copyOf(value.entries);
	}

	/**
	 * Prepends the specified values to the beginning of this list.
	 *
	 * @param values The values to prepend to this list.
	 * @return This object.
	 */
	public DefaultClassList add(Class<?>...values) {
		prependAll(entries, values);
		return this;
	}

	/**
	 * Returns the first class in this list which is a subclass of (or same as) the specified type.
	 *
	 * @param <T> The parent type.
	 * @param type The parent type to check for.
	 * @return The first class in this list which is a subclass of the specified type.
	 */
	@SuppressWarnings("unchecked")
	public <T> Optional<Class<? extends T>> get(Class<T> type) {
		assertArgNotNull("type", type);
		for (Class<?> e : entries)
			if (e != null && type.isAssignableFrom(e))
				return optional((Class<? extends T>)e);
		return empty();
	}

	/**
	 * Creates a copy of this list.
	 *
	 * @return A copy of this list.
	 */
	public DefaultClassList copy() {
		return new DefaultClassList(this);
	}
}