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.io.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 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    }