/*

 * Copyright 2000-2003 Sun Microsystems, Inc.  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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package java.security.cert;

import java.security.InvalidAlgorithmParameterException;

import java.util.Collection;

/**

 * The <i>Service Provider Interface</i> (<b>SPI</b>)

 * for the {@link CertStore CertStore} class. All <code>CertStore</code>

 * implementations must include a class (the SPI class) that extends

 * this class (<code>CertStoreSpi</code>), provides a constructor with

 * a single argument of type <code>CertStoreParameters</code>, and implements

 * all of its methods. In general, instances of this class should only be

 * accessed through the <code>CertStore</code> class.

 * For details, see the Java Cryptography Architecture.

 * <p>

 * <b>Concurrent Access</b>

 * <p>

 * The public methods of all <code>CertStoreSpi</code> objects must be

 * thread-safe. That is, multiple threads may concurrently invoke these

 * methods on a single <code>CertStoreSpi</code> object (or more than one)

 * with no ill effects. This allows a <code>CertPathBuilder</code> to search

 * for a CRL while simultaneously searching for further certificates, for

 * instance.

 * <p>

 * Simple <code>CertStoreSpi</code> implementations will probably ensure

 * thread safety by adding a <code>synchronized</code> keyword to their

 * <code>engineGetCertificates</code> and <code>engineGetCRLs</code> methods.

 * More sophisticated ones may allow truly concurrent access.

 *

 * @since       1.4

 * @author      Steve Hanna

 */

public abstract class CertStoreSpi {

    /**

     * The sole constructor.

     *

     * @param params the initialization parameters (may be <code>null</code>)

     * @throws InvalidAlgorithmParameterException if the initialization

     * parameters are inappropriate for this <code>CertStoreSpi</code>

     */

    public CertStoreSpi(CertStoreParameters params)

    throws InvalidAlgorithmParameterException { }

    /**

     * Returns a <code>Collection</code> of <code>Certificate</code>s that

     * match the specified selector. If no <code>Certificate</code>s

     * match the selector, an empty <code>Collection</code> will be returned.

     * <p>

     * For some <code>CertStore</code> types, the resulting

     * <code>Collection</code> may not contain <b>all</b> of the

     * <code>Certificate</code>s that match the selector. For instance,

     * an LDAP <code>CertStore</code> may not search all entries in the

     * directory. Instead, it may just search entries that are likely to

     * contain the <code>Certificate</code>s it is looking for.

     * <p>

     * Some <code>CertStore</code> implementations (especially LDAP

     * <code>CertStore</code>s) may throw a <code>CertStoreException</code>

     * unless a non-null <code>CertSelector</code> is provided that includes

     * specific criteria that can be used to find the certificates. Issuer

     * and/or subject names are especially useful criteria.

     *

     * @param selector A <code>CertSelector</code> used to select which

     *  <code>Certificate</code>s should be returned. Specify <code>null</code>

     *  to return all <code>Certificate</code>s (if supported).

     * @return A <code>Collection</code> of <code>Certificate</code>s that

     *         match the specified selector (never <code>null</code>)

     * @throws CertStoreException if an exception occurs

     */

    public abstract Collection<? extends Certificate> engineGetCertificates

            (CertSelector selector) throws CertStoreException;

    /**

     * Returns a <code>Collection</code> of <code>CRL</code>s that

     * match the specified selector. If no <code>CRL</code>s

     * match the selector, an empty <code>Collection</code> will be returned.

     * <p>

     * For some <code>CertStore</code> types, the resulting

     * <code>Collection</code> may not contain <b>all</b> of the

     * <code>CRL</code>s that match the selector. For instance,

     * an LDAP <code>CertStore</code> may not search all entries in the

     * directory. Instead, it may just search entries that are likely to

     * contain the <code>CRL</code>s it is looking for.

     * <p>

     * Some <code>CertStore</code> implementations (especially LDAP

     * <code>CertStore</code>s) may throw a <code>CertStoreException</code>

     * unless a non-null <code>CRLSelector</code> is provided that includes

     * specific criteria that can be used to find the CRLs. Issuer names

     * and/or the certificate to be checked are especially useful.

     *

     * @param selector A <code>CRLSelector</code> used to select which

     *  <code>CRL</code>s should be returned. Specify <code>null</code>

     *  to return all <code>CRL</code>s (if supported).

     * @return A <code>Collection</code> of <code>CRL</code>s that

     *         match the specified selector (never <code>null</code>)

     * @throws CertStoreException if an exception occurs

     */

    public abstract Collection<? extends CRL> engineGetCRLs

            (CRLSelector selector) throws CertStoreException;

}