001/*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019
020package org.crsh.command;
021
022import org.crsh.io.Filter;
023import org.crsh.util.Utils;
024
025import java.io.IOException;
026
027/**
028 * A command pipe.
029 *
030 * @param <C> the consumed generic type
031 * @param <P> the produced generic type
032 */
033public abstract class Pipe<C, P> implements Filter<C, P, InvocationContext<P>> {
034
035  /** . */
036  protected InvocationContext<P> context;
037
038  public final boolean isPiped() {
039    return context.isPiped();
040  }
041
042  public final Class<P> getProducedType() {
043    return (Class<P>)Utils.resolveToClass(getClass(), Pipe.class, 1);
044  }
045
046  public final Class<C> getConsumedType() {
047    return (Class<C>)Utils.resolveToClass(getClass(), Pipe.class, 0);
048  }
049
050  public void open(InvocationContext<P> consumer) {
051    this.context = consumer;
052
053    //
054    open();
055  }
056
057  /**
058   * Open pipe.
059   */
060  public void open() throws ScriptException {
061  }
062
063  /**
064   * Extends the throw clause of the {@link org.crsh.io.Consumer#provide(Object)} method.
065   *
066   * @param element the provided element
067   * @throws ScriptException any script exception
068   * @throws IOException any io exception
069   */
070  public void provide(C element) throws ScriptException, IOException {
071  }
072
073  /**
074   * Flush pipe.
075   *
076   * @throws ScriptException any script exception
077   * @throws IOException any io exception
078   */
079  public void flush() throws ScriptException, IOException {
080    context.flush();
081  }
082
083  /**
084   * Close pipe.
085   *
086   * @throws ScriptException any script exception
087   */
088  public void close() throws ScriptException, IOException {
089    context.close();
090  }
091}