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 */
019package org.crsh.cli.impl.lang;
020
021/**
022 * @author Julien Viet
023 */
024public interface Instance<T> {
025
026  /**
027   * Resolve the specified contextual type to an instance or return null if no object able
028   * to satisfy the class type was resolved.
029   *
030   * @param type the type to resolve
031   * @param <T> the generic type parameter
032   * @return the resolved instance
033   */
034  <T> T resolve(Class<T> type);
035
036  /**
037   * Return the instance, the same instance should be returned, however it can lazily be created.
038   *
039   * @return the instance
040   * @throws Exception any exception preventing to obtain the instance
041   */
042  T get() throws Exception;
043
044}