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    
020    package org.crsh.command;
021    
022    import org.crsh.stream.Filter;
023    import org.crsh.util.Utils;
024    
025    import 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     */
033    public abstract class Pipe<C, P> implements Filter<C, P, InvocationContext<P>> {
034    
035      /** . */
036      protected InvocationContext<P> context;
037    
038      public final Class<P> getProducedType() {
039        return (Class<P>)Utils.resolveToClass(getClass(), Pipe.class, 1);
040      }
041    
042      public final Class<C> getConsumedType() {
043        return (Class<C>)Utils.resolveToClass(getClass(), Pipe.class, 0);
044      }
045    
046      public void open(InvocationContext<P> consumer) throws Exception {
047        this.context = consumer;
048    
049        //
050        open();
051      }
052    
053      /**
054       * Open pipe.
055       */
056      public void open() throws Exception {
057      }
058    
059      public void provide(C element) throws Exception {
060      }
061    
062      /**
063       * Flush pipe.
064       *
065       * @throws IOException any io exception
066       */
067      public void flush() throws IOException {
068        context.flush();
069      }
070    
071      /**
072       * Close pipe.
073       *
074       * @throws Exception any exception
075       */
076      public void close() throws Exception {
077        context.close();
078      }
079    }