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 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package java.security.cert;

import java.io.Serializable;

import java.util.Collection;

import java.util.Collections;

/**

 * Parameters used as input for the Collection {@code CertStore}

 * algorithm.

 * <p>

 * This class is used to provide necessary configuration parameters

 * to implementations of the Collection {@code CertStore}

 * algorithm. The only parameter included in this class is the

 * {@code Collection} from which the {@code CertStore} will

 * retrieve certificates and CRLs.

 * <p>

 * <b>Concurrent Access</b>

 * <p>

 * Unless otherwise specified, the methods defined in this class are not

 * thread-safe. Multiple threads that need to access a single

 * object concurrently should synchronize amongst themselves and

 * provide the necessary locking. Multiple threads each manipulating

 * separate objects need not synchronize.

 *

 * @since       1.4

 * @author      Steve Hanna

 * @see         java.util.Collection

 * @see         CertStore

 */

public class CollectionCertStoreParameters

    implements CertStoreParameters {

    private Collection<?> coll;

    /**

     * Creates an instance of {@code CollectionCertStoreParameters}

     * which will allow certificates and CRLs to be retrieved from the

     * specified {@code Collection}. If the specified

     * {@code Collection} contains an object that is not a

     * {@code Certificate} or {@code CRL}, that object will be

     * ignored by the Collection {@code CertStore}.

     * <p>

     * The {@code Collection} is <b>not</b> copied. Instead, a

     * reference is used. This allows the caller to subsequently add or

     * remove {@code Certificates} or {@code CRL}s from the

     * {@code Collection}, thus changing the set of

     * {@code Certificates} or {@code CRL}s available to the

     * Collection {@code CertStore}. The Collection {@code CertStore}

     * will not modify the contents of the {@code Collection}.

     * <p>

     * If the {@code Collection} will be modified by one thread while

     * another thread is calling a method of a Collection {@code CertStore}

     * that has been initialized with this {@code Collection}, the

     * {@code Collection} must have fail-fast iterators.

     *

     * @param collection a {@code Collection} of

     *        {@code Certificate}s and {@code CRL}s

     * @exception NullPointerException if {@code collection} is

     * {@code null}

     */

    public CollectionCertStoreParameters(Collection<?> collection) {

        if (collection == null)

            throw new NullPointerException();

        coll = collection;

    }

    /**

     * Creates an instance of {@code CollectionCertStoreParameters} with

     * the default parameter values (an empty and immutable

     * {@code Collection}).

     */

    public CollectionCertStoreParameters() {

        coll = Collections.EMPTY_SET;

    }

    /**

     * Returns the {@code Collection} from which {@code Certificate}s

     * and {@code CRL}s are retrieved. This is <b>not</b> a copy of the

     * {@code Collection}, it is a reference. This allows the caller to

     * subsequently add or remove {@code Certificates} or

     * {@code CRL}s from the {@code Collection}.

     *

     * @return the {@code Collection} (never null)

     */

    public Collection<?> getCollection() {

        return coll;

    }

    /**

     * Returns a copy of this object. Note that only a reference to the

     * {@code Collection} is copied, and not the contents.

     *

     * @return the copy

     */

    public Object clone() {

        try {

            return super.clone();

        } catch (CloneNotSupportedException e) {

            /* Cannot happen */

            throw new InternalError(e.toString(), e);

        }

    }

    /**

     * Returns a formatted string describing the parameters.

     *

     * @return a formatted string describing the parameters

     */

    public String toString() {

        StringBuilder sb = new StringBuilder();

        sb.append("CollectionCertStoreParameters: [\n");

        sb.append("  collection: " + coll + "\n");

        sb.append("]");

        return sb.toString();

    }

}