| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.commons.chain2; |
| |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| /** |
| * A <code>CatalogFactory</code> stores and retrieves catalogs. |
| * <p> |
| * The factory allows for a default {@link Catalog} as well as Catalog's |
| * stored with a name key. It follows the Factory pattern (see GoF). |
| * <p> |
| * The base implementation provides command lookup based on a single |
| * String. This String encodes both the catalog and command names. |
| * |
| * @param <K> the type of keys maintained by the context associated with this {@link Command} |
| * @param <V> the type of mapped values |
| * @param <C> Type of the context associated with this command |
| * |
| * @version $Id: CatalogFactory.java 1486528 2013-05-27 07:38:38Z simonetripodi $ |
| */ |
| public interface CatalogFactory<K, V, C extends Map<K, V>> { |
| |
| /** |
| * <p>Values passed to the <code>getCommand(String)</code> method should |
| * use this as the delimiter between the "catalog" name and the "command" |
| * name.</p> |
| */ |
| public static final String DELIMITER = ":"; |
| |
| /** |
| * <p>Gets the default instance of Catalog associated with the factory |
| * (if any); otherwise, return <code>null</code>.</p> |
| * |
| * @return the default Catalog instance |
| */ |
| public abstract Catalog<K, V, C> getCatalog(); |
| |
| /** |
| * <p>Sets the default instance of Catalog associated with the factory.</p> |
| * |
| * @param catalog the default Catalog instance |
| */ |
| public abstract void setCatalog(Catalog<K, V, C> catalog); |
| |
| /** |
| * <p>Retrieves a Catalog instance by name (if any); otherwise |
| * return <code>null</code>.</p> |
| * |
| * @param name the name of the Catalog to retrieve |
| * @return the specified Catalog |
| */ |
| public abstract Catalog<K, V, C> getCatalog(String name); |
| |
| /** |
| * <p>Adds a named instance of Catalog to the factory (for subsequent |
| * retrieval later).</p> |
| * |
| * @param name the name of the Catalog to add |
| * @param catalog the Catalog to add |
| */ |
| public abstract void addCatalog(String name, Catalog<K, V, C> catalog); |
| |
| /** |
| * <p>Return an <code>Iterator</code> over the set of named |
| * {@link Catalog}s known to this instance. |
| * If there are no known catalogs, an empty Iterator is returned.</p> |
| * @return An Iterator of the names of the Catalogs known by this factory. |
| */ |
| public abstract Iterator<String> getNames(); |
| |
| /** |
| * <p>Return a <code>Command</code> based on the given commandID.</p> |
| * |
| * <p>At this time, the structure of commandID is relatively simple: if the |
| * commandID contains a DELIMITER, treat the segment of the commandID |
| * up to (but not including) the DELIMITER as the name of a catalog, and the |
| * segment following the DELIMITER as a command name within that catalog. |
| * If the commandID contains no DELIMITER, treat the commandID as the name |
| * of a command in the default catalog.</p> |
| * |
| * <p>To preserve the possibility of future extensions to this lookup |
| * mechanism, the DELIMITER string should be considered reserved, and |
| * should not be used in command names. commandID values which contain |
| * more than one DELIMITER will cause an |
| * <code>IllegalArgumentException</code> to be thrown.</p> |
| * |
| * @param <CMD> the expected {@link Command} type to be returned |
| * @param commandID the identifier of the command to return |
| * @return the command located with commandID, or <code>null</code> |
| * if either the command name or the catalog name cannot be resolved |
| * @throws IllegalArgumentException if the commandID contains more than |
| * one DELIMITER |
| * |
| * @since Chain 1.1 |
| */ |
| public abstract <CMD extends Command<K, V, C>> CMD getCommand( |
| String commandID); |
| |
| } |