| /* |
| * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//pool/src/java/org/apache/commons/pool/ObjectPool.java,v 1.1 2001/04/14 16:40:49 rwaldhoff Exp $ |
| * $Revision: 1.1 $ |
| * $Date: 2001/04/14 16:40:49 $ |
| * |
| * ==================================================================== |
| * |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 1999-2001 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 acknowlegement: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowlegement may appear in the software itself, |
| * if and wherever such third-party acknowlegements normally appear. |
| * |
| * 4. The names "The Jakarta Project", "Commons", and "Apache Software |
| * Foundation" must not be used to endorse or promote products derived |
| * from this software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache" |
| * nor may "Apache" appear in their names without prior written |
| * permission of the Apache Group. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * 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; |
| |
| /** |
| * A simple {@link Object} pooling interface. |
| * <p> |
| * Example of use: |
| * <table border="1" cellspacing="0" cellpadding="3" align="center" bgcolor="#FFFFFF"><tr><td><pre> |
| * Object obj = <font color="#0000CC">null</font>; |
| * <font color="#0000CC">try</font> { |
| * obj = pool.borrowObject(); |
| * <font color="#00CC00">//...use the object...</font> |
| * } <font color="#0000CC">catch</font>(Exception e) { |
| * <font color="#00CC00">//...handle any exceptions...</font> |
| * } <font color="#0000CC">finally</font> { |
| * <font color="#00CC00">// make sure the object is returned to the pool</font> |
| * <font color="#0000CC">if</font>(<font color="#0000CC">null</font> != obj) { |
| * pool.returnObject(obj); |
| * } |
| * }</pre></td></tr></table> |
| * |
| * @author Rodney Waldhoff |
| * @version $Id: ObjectPool.java,v 1.1 2001/04/14 16:40:49 rwaldhoff Exp $ |
| * |
| * @see KeyedObjectPool |
| * @see ObjectPoolFactory |
| * @see PoolableObjectFactory |
| */ |
| public interface ObjectPool { |
| /** |
| * Obtain an <tt>Object</tt> from my pool. |
| * By contract, clients MUST return |
| * the borrowed object using |
| * {@link #returnObject(java.lang.Object) <tt>returnObject</tt>} |
| * or a related method as defined in an implementation |
| * or sub-interface. |
| * <p> |
| * The behaviour of this method when the pool has been exhausted |
| * is not specified (although it may be specified by implementations). |
| * |
| * @return an <tt>Object</tt> from my pool. |
| */ |
| public abstract Object borrowObject(); |
| |
| /** |
| * Return an <tt>Object</tt> to my pool. |
| * By contract, <i>obj</i> MUST have been obtained |
| * using {@link #borrowObject() <tt>borrowObject</tt>} |
| * or a related method as defined in an implementation |
| * or sub-interface. |
| * |
| * @param obj a {@link #borrowObject() borrowed} <tt>Object</tt> to be returned. |
| */ |
| public abstract void returnObject(Object obj); |
| |
| /** |
| * Return the number of <tt>Object</tt>s |
| * currently idle in my pool, or |
| * throws {@link UnsupportedOperationException} |
| * if this information is not available. |
| * |
| * @return the number of <tt>Object</tt>s currently idle in my pool |
| * @throws UnsupportedOperationException |
| */ |
| public abstract int numIdle() throws UnsupportedOperationException; |
| |
| /** |
| * Return the number of <tt>Object</tt>s |
| * currently borrowed from my pool, or |
| * throws {@link UnsupportedOperationException} |
| * if this information is not available. |
| * |
| * @return the number of <tt>Object</tt>s currently borrowed in my pool |
| * @throws UnsupportedOperationException |
| */ |
| public abstract int numActive() throws UnsupportedOperationException; |
| |
| /** |
| * Clears any objects sitting idle in the pool, releasing any |
| * associated resources, or throws {@link UnsupportedOperationException} |
| * if the pool cannot be cleared. |
| * |
| * @throws UnsupportedOperationException |
| */ |
| public abstract void clear() throws UnsupportedOperationException; |
| |
| /** |
| * Close this pool, and free any resources associated with it. |
| */ |
| public abstract void close(); |
| |
| /** |
| * Sets the {@link PoolableObjectFactory factory} I use |
| * to create new instances. |
| * @param factory the {@link PoolableObjectFactory} I use to create new instances. |
| */ |
| public abstract void setFactory(PoolableObjectFactory factory) throws IllegalStateException, UnsupportedOperationException; |
| } |