connectionprovider.java

基于Jabber协议的即时消息服务器

/**
 * $RCSfile$
 * $Revision: 37 $
 * $Date: 2004-10-20 23:08:43 -0700 (Wed, 20 Oct 2004) $
 *
 * Copyright (C) 2004 Jive Software. All rights reserved.
 *
 * This software is published under the terms of the GNU Public License (GPL),
 * a copy of which is included in this distribution.
 */

package org.jivesoftware.database;

import java.sql.Connection;
import java.sql.SQLException;

/**
 * Abstract class that defines the connection provider framework. Other classes
 * extend this abstract class to make connection to actual data sources.<p>
 * <p/>
 * It is expected that each subclass be a JavaBean, so that properties of
 * the connection provider are exposed through bean introspection.
 *
 * @author Jive Software
 */
public interface ConnectionProvider {

    /**
     * Returns true if this connection provider provides connections out
     * of a connection pool. Implementing and using connection providers that
     * are pooled is strongly recommended, as they greatly increase the speed
     * of Jive.
     *
     * @return true if the Connection objects returned by this provider are
     *         pooled.
     */
    public boolean isPooled();

    /**
     * Returns a database connection. When a Jive component is done with a
     * connection, it will call the close method of that connection. Therefore,
     * connection pools with special release methods are not directly
     * supported by the connection provider infrastructure. Instead, connections
     * from those pools should be wrapped such that calling the close method
     * on the wrapper class will release the connection from the pool.
     *
     * @return a Connection object.
     */
    public Connection getConnection() throws SQLException;

    /**
     * Starts the connection provider. For some connection providers, this
     * will be a no-op. However, connection provider users should always call
     * this method to make sure the connection provider is started.
     */
    public void start();

    /**
     * This method should be called whenever properties have been changed so
     * that the changes will take effect.
     */
    public void restart();

    /**
     * Tells the connection provider to destroy itself. For many connection
     * providers, this will essentially result in a no-op. However,
     * connection provider users should always call this method when changing
     * from one connection provider to another to ensure that there are no
     * dangling database connections.
     */
    public void destroy();
}