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/*
 * Copyright (c) 2010, 2020, Oracle and/or its affiliates.
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, version 2.0, as published by the
 * Free Software Foundation.
 *
 * This program is also distributed with certain software (including but not
 * limited to OpenSSL) that is licensed under separate terms, as designated in a
 * particular file or component or in included license documentation. The
 * authors of MySQL hereby grant you an additional permission to link the
 * program and your derivative works with the separately licensed software that
 * they have included with MySQL.
 *
 * Without limiting anything contained in the foregoing, this file, which is
 * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
 * version 1.0, a copy of which can be found at
 * http://oss.oracle.com/licenses/universal-foss-exception.
 *
 * This program 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 2.0,
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
 */

package com.mysql.cj.jdbc.ha;

import java.util.Properties;

public interface LoadBalanceExceptionChecker {

    /**
     * Called once per connection that wants to use the extension
     * 
     * The properties are the same ones passed in in the URL or arguments to
     * Driver.connect() or DriverManager.getConnection().
     * 
     * @param props
     *            configuration values as passed to the connection. Note that
     *            in order to support javax.sql.DataSources, configuration properties specific
     *            to an interceptor must be passed via setURL() on the
     *            DataSource. Extension properties are not exposed via
     *            accessor/mutator methods on DataSources.
     */
    void init(Properties props);

    /**
     * Called by the driver when this extension should release any resources
     * it is holding and cleanup internally before the connection is
     * closed.
     */
    void destroy();

    /**
     * Invoked to determine whether or a given SQLException should
     * trigger a failover in a load-balanced deployment.
     * 
     * The driver will not pass in a Connection instance when calling init(), but it
     * will pass in the Properties, otherwise it acts like a normal Extension.
     * 
     * One instance of a handler *per* JDBC connection instance will be created. If
     * you need singleton-like behavior, you're on your own to provide it.
     * 
     * @param ex
     *            exception
     * @return true if the exception should trigger failover.
     */
    boolean shouldExceptionTriggerFailover(Throwable ex);

}