| package org.apache.turbine.pipeline; |
| |
| /* ==================================================================== |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 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 acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Apache" and "Apache Software Foundation" and |
| * "Apache Turbine" 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", |
| * "Apache Turbine", nor may "Apache" appear in their name, without |
| * prior written permission of the Apache Software Foundation. |
| * |
| * 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/>. |
| */ |
| |
| import java.io.IOException; |
| |
| import org.apache.turbine.util.TurbineException; |
| |
| /** |
| * The idea of a pipeline is being taken from Catalina |
| * in its entirety :-) |
| * |
| * I would like to take the idea further and implement |
| * Valves instead of hardcoding particular methods |
| * in a pipeline. |
| * |
| * It would be more flexible to specify Valves for |
| * a pipeline in an XML file (we can also rip off the |
| * digester rules from T4) and have invoke() as part |
| * of the interface. |
| * |
| * So a set of Valves would be added to the pipeline |
| * and the pipeline would 'invoke' each valve. In the |
| * case Turbine each Valve would produce some output |
| * to be sent out the pipe. I think with another days |
| * work this can be fully working. The first pipeline |
| * to be fully implemented will the ClassicPipeline |
| * will emulate the Turbine 2.1 way of doing things. |
| * |
| * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> |
| * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a> |
| * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a> |
| */ |
| public interface Pipeline |
| { |
| /** |
| * Initializes this instance. Called once by the Turbine servlet. |
| */ |
| public void initialize() |
| throws Exception; |
| |
| /** |
| * <p>Add a new Valve to the end of the pipeline.</p> |
| * |
| * @param valve Valve to be added. |
| * |
| * @exception IllegalStateException If the pipeline has not been |
| * initialized. |
| */ |
| public void addValve(Valve valve); |
| |
| /** |
| * Return the set of all Valves in the pipeline. If there are no |
| * such Valves, a zero-length array is returned. |
| * |
| * @return An array of valves. |
| */ |
| public Valve[] getValves(); |
| |
| /** |
| * <p>Cause the specified request and response to be processed by |
| * the sequence of Valves associated with this pipeline, until one |
| * of these Valves decides to end the processing.</p> |
| * |
| * <p>The implementation must ensure that multiple simultaneous |
| * requests (on different threads) can be processed through the |
| * same Pipeline without interfering with each other's control |
| * flow.</p> |
| * |
| * @param data The run-time information, including the servlet |
| * request and response we are processing. |
| * |
| * @exception IOException an input/output error occurred. |
| */ |
| public void invoke(PipelineData data) |
| throws TurbineException, IOException; |
| |
| /** |
| * Remove the specified Valve from the pipeline, if it is found; |
| * otherwise, do nothing. |
| * |
| * @param valve Valve to be removed. |
| */ |
| public void removeValve(Valve valve); |
| } |