/*
 * $Source: /home/cvs/commons/pool1.1/ja/src/org/apache/commons/pool/KeyedPoolableObjectFactory.java,v $
 * $Revision: 1.1 $
 * $Date: 2004/02/22 11:58:26 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowledgement:
 *       "This product includes software developed by the
 *        Apache Software Foundation - http://www.apache.org/"
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements normally appear.
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 *    Foundation" must not be used to endorse or promote products derived
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 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * http://www.apache.org/
 *
 */

package org.apache.commons.pool;

/**
 * {@link KeyedObjectPool KeyedObjectPool} に保持されるインスタンスの
 * ライフサイクルに関するメソッドを定義したインターフェイスです。
 * {@primary An interface defining life-cycle methods for
 * instances to be served by a
 * {@link KeyedObjectPool KeyedObjectPool}.}
 * <p>
 * {@link KeyedObjectPool KeyedObjectPool} を生成する際に
 * <tt>KeyedPoolableObjectFactory</tt> が指定され、以下の処理が行われます。
 * {@primary By contract, when an {@link KeyedObjectPool KeyedObjectPool}
 * delegates to a <tt>KeyedPoolableObjectFactory</tt>,}
 * <ol>
 *  <li>
 *   新たなインスタンスが必要となった場合
 *   {@link #makeObject makeObject} が呼ばれます。
 *   {@primary {@link #makeObject makeObject} 
 *   is called  whenever a new instance is needed.}
 *  </li>
 *  <li>
 *   プールからインスタンスが渡される前には
 *   {@link #activateObject activateObject} が実施されます。
 *   {@primary {@link #activateObject activateObject} 
 *   is invoked on every instance before it is returned from the
 *   pool.}
 *  </li>
 *  <li>
 *   プールにインスタンスが戻されると
 *   {@link #passivateObject passivateObject} が実施されます。
 *   {@primary {@link #passivateObject passivateObject} 
 *   is invoked on every instance when it is returned to the
 *   pool.}
 *  </li>
 *  <li>
 *   ( {@link #validateObject validateObject} の結果またはプールの実装に指定された理由によって)
 *   プールからインスタンスが取り除かれる場合には
 *   {@link #destroyObject destroyObject} が実施されます。
 *   {@primary {@link #destroyObject destroyObject} 
 *   is invoked on every instance when it is being "dropped" from the
 *   pool (whether due to the response from
 *   {@link #validateObject validateObject}, or
 *   for reasons specific to the pool implementation.)}
 *  </li>
 *  <li>
 *   各実装がプール内のインスタンスが有効な状態かどうか判断するための方法として
 *   {@link #validateObject validateObject} が実施されます。
 *   これは {@link #activateObject "activated"} なインスタンスに対してのみ行われます。
 *   {@primary {@link #validateObject validateObject} 
 *   is invoked in an implementation-specific fashion to determine if an instance
 *   is still valid to be returned by the pool.
 *   It will only be invoked on an {@link #activateObject "activated"}
 *   instance.}
 *  </li>
 * </ol>
 *
 * @author Rodney Waldhoff
 * @version $Revision: 1.1 $ $Date: 2004/02/22 11:58:26 $ 
 *
 * @see KeyedObjectPool
 *
 * @translator 日置 聡
 * @status firstdraft
 * @update 2004/02/21
 */
public interface KeyedPoolableObjectFactory {
    /**
     * プールに保持されるインスタンスを生成します。
     * {@primary Create an instance that can be served by the pool.}
     * @param key オブジェクトを生成する際に使用されるキー
     * {@primary the key used when constructing the object}
     * @return プールに保持されるインスタンス
     * {@primary instance that can be served by the pool.}
     */
    Object makeObject(Object key) throws Exception;

    /**
     * プールで必要のなくなったインスタンスを破棄します。
     * {@primary Destroys an instance no longer needed by the pool.}
     * @param key インスタンスを選択する際に使用されるキー
     * {@primary the key used when selecting the instance}
     * @param obj 破棄されるインスタンス
     * {@primary the instance to be destroyed}
     */
    void destroyObject(Object key, Object obj) throws Exception;

    /**
     * このインスタンスがプールにて安全に使用できるかを判断します。
     * このオブジェクトを破棄するべき場合には <tt>false</tt> を返します。
     * {@primary Ensures that the instance is safe to be returned by the pool.
     * Returns <tt>false</tt> if this object should be destroyed.}
     * @param key オブジェクトを選択する際に使用されるキー
     * {@primary the key used when selecting the object}
     * @param obj チェックを行うインスタンス
     * {@primary the instance to be validated}
     * @return <i>obj</i> が無効でプールから削除すべき場合 <tt>false</tt>、
     *         それ以外の場合 <tt>true</tt>
     * {@primary <tt>false</tt> if this <i>obj</i> is not valid and should
     *           be dropped from the pool, <tt>true</tt> otherwise.}
     */
    boolean validateObject(Object key, Object obj);

    /**
     * プールから取り出されるインスタンスの初期化を行います。
     * {@primary Reinitialize an instance to be returned by the pool.}
     * @param key オブジェクトを選択する際に使用されるキー
     * {@primary the key used when selecting the object}
     * @param obj プールから取り出されるインスタンス
     * {@primary the instance to be activated}
     */
    void activateObject(Object key, Object obj) throws Exception;

    /**
     * プールに戻されたインスタンスの後処理を行います。
     * {@primary Uninitialize an instance to be returned to the pool.}
     * @param key オブジェクトを選択する際に使用されるキー
     * {@primary the key used when selecting the object}
     * @param obj プールに戻されたインスタンス
     * {@primary the instance to be passivated}
     */
    void passivateObject(Object key, Object obj) throws Exception;
}