001    /*
002     * Copyright (C) 2003-2009 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    package org.crsh.command;
020    
021    /**
022     * The class command is a specialization of the {@link BaseCommand} for simple command implementations.
023     *
024     * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
025     * @version $Revision$
026     */
027    public abstract class ClassCommand extends BaseCommand<Void, Void> {
028    
029      protected ClassCommand() {
030      }
031    
032      @Override
033      protected void execute(InvocationContext<Void, Void> context) throws ScriptException {
034    
035        //
036        Object o = execute();
037    
038        //
039        if (o != null) {
040          context.getWriter().print(o);
041        }
042      }
043    
044      protected abstract Object execute() throws ScriptException;
045    
046    }