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 * 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 javax.net.ssl;

import java.util.Enumeration;

/**

 * A <code>SSLSessionContext</code> represents a set of

 * <code>SSLSession</code>s associated with a single entity. For example,

 * it could be associated with a server or client who participates in many

 * sessions concurrently.

 * <p>

 * <p>

 * There are <code>SSLSessionContext</code> parameters that affect how

 * sessions are stored:

 * <UL>

 *      <LI>Sessions can be set to expire after a specified

 *      time limit.

 *      <LI>The number of sessions that can be stored in context

 *      can be limited.

 * </UL>

 * A session can be retrieved based on its session id, and all session id's

 * in a <code>SSLSessionContext</code> can be listed.

 *

 * @see SSLSession

 *

 * @since 1.4

 * @author Nathan Abramson

 * @author David Brownell

 */

public interface SSLSessionContext {

    /**

     * Returns the <code>SSLSession</code> bound to the specified session id.

     *

     * @param sessionId the Session identifier

     * @return the <code>SSLSession</code> or null if

     * the specified session id does not refer to a valid SSLSession.

     *

     * @throws NullPointerException if <code>sessionId</code> is null.

     */

    public SSLSession getSession(byte[] sessionId);

    /**

     * <code>SSLSessionContext</code>.

     *

     * @return an enumeration of all the Session id's

     */

    public Enumeration<byte[]> getIds();

    /**

     * Sets the timeout limit for <code>SSLSession</code> objects grouped

     * under this <code>SSLSessionContext</code>.

     * <p>

     * If the timeout limit is set to 't' seconds, a session exceeds the

     * timeout limit 't' seconds after its creation time.

     * When the timeout limit is exceeded for a session, the

     * <code>SSLSession</code> object is invalidated and future connections

     * cannot resume or rejoin the session.

     * A check for sessions exceeding the timeout is made immediately whenever

     * the timeout limit is changed for this <code>SSLSessionContext</code>.

     *

     * @apiNote Note that the JDK Implementation uses default values for both

     *          the session cache size and timeout.  See

     *          {@code getSessionCacheSize} and {@code getSessionTimeout} for

     *          more information.  Applications should consider their

     *          performance requirements and override the defaults if necessary.

     *

     * @param seconds the new session timeout limit in seconds; zero means

     *        there is no limit.

     *

     * @throws IllegalArgumentException if the timeout specified is {@code < 0}.

     *

     * @see #getSessionTimeout

     */

    public void setSessionTimeout(int seconds)

                 throws IllegalArgumentException;

    /**

     * Returns the timeout limit of <code>SSLSession</code> objects grouped

     * under this <code>SSLSessionContext</code>.

     * <p>

     * If the timeout limit is set to 't' seconds, a session exceeds the

     * timeout limit 't' seconds after its creation time.

     * When the timeout limit is exceeded for a session, the

     * <code>SSLSession</code> object is invalidated and future connections

     * cannot resume or rejoin the session.

     * A check for sessions exceeding the timeout limit is made immediately

     * whenever the timeout limit is changed for this

     * <code>SSLSessionContext</code>.

     *

     * @implNote The JDK implementation returns the session timeout as set by

     *           the {@code setSessionTimeout} method, or if not set, a default

     *           value of 86400 seconds (24 hours).

     *

     * @return the session timeout limit in seconds; zero means there is no

     *         limit.

     *

     * @see #setSessionTimeout

     */

    public int getSessionTimeout();

    /**

     * Sets the size of the cache used for storing <code>SSLSession</code>

     * objects grouped under this <code>SSLSessionContext</code>.

     *

     * @apiNote Note that the JDK Implementation uses default values for both

     *          the session cache size and timeout.  See

     *          {@code getSessionCacheSize} and {@code getSessionTimeout} for

     *          more information.  Applications should consider their

     *          performance requirements and override the defaults if necessary.

     *

     * @param size the new session cache size limit; zero means there is no

     *        limit.

     *

     * @throws IllegalArgumentException if the specified size is {@code < 0}.

     *

     * @see #getSessionCacheSize

     */

    public void setSessionCacheSize(int size)

                 throws IllegalArgumentException;

    /**

     * Returns the size of the cache used for storing <code>SSLSession</code>

     * objects grouped under this <code>SSLSessionContext</code>.

     *

     * @implNote The JDK implementation returns the cache size as set by

     *           the {@code setSessionCacheSize} method, or if not set, the

     *           value of the {@systemProperty javax.net.ssl.sessionCacheSize}

     *           system property.  If neither is set, it returns a default

     *           value of 20480.

     *

     * @return size of the session cache; zero means there is no size limit.

     *

     * @see #setSessionCacheSize

     */

    public int getSessionCacheSize();

}