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    package org.crsh.shell.impl.command.spi;
020    
021    import java.util.Map;
022    
023    /**
024     * Resolve commands.
025     *
026     * @author Julien Viet
027     */
028    public interface CommandResolver {
029    
030      /**
031       * @return the known command names by this resolver, the returned map keys are the command names
032       *         and the values are the corresponding one line description of the command
033       */
034      Iterable<Map.Entry<String, String>> getDescriptions();
035    
036      /**
037       * Attempt to obtain a command. Null is returned when such command does not exist.
038       *
039       * @param name the command name
040       * @return the command shell
041       * @throws CommandException if an error occured preventing the command creation
042       * @throws NullPointerException if the name argument is null
043       */
044      Command<?> resolveCommand(String name) throws CommandException, NullPointerException;
045    }