org.apache.commons.chain.Catalog Maven / Gradle / Ivy
/*
* 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.chain;
import java.util.Iterator;
/**
* A {@link Catalog} is a collection of named {@link Command}s (or
* {@link Chain}s) that can be used to retrieve the set of commands that
* should be performed based on a symbolic identifier. Use of catalogs
* is optional, but convenient when there are multiple possible chains
* that can be selected and executed based on environmental conditions.
*
* @author Craig R. McClanahan
* @version $Revision: 480477 $ $Date: 2006-11-29 08:34:52 +0000 (Wed, 29 Nov 2006) $
*/
public interface Catalog {
/**
* A default context attribute for storing a default {@link Catalog},
* provided as a convenience only.
*/
String CATALOG_KEY = "org.apache.commons.chain.CATALOG";
/**
* Add a new name and associated {@link Command} or {@link Chain}
* to the set of named commands known to this {@link Catalog},
* replacing any previous command for that name.
*
* @param name Name of the new command
* @param command {@link Command} or {@link Chain} to be returned
* for later lookups on this name
*/
void addCommand(String name, Command command);
/**
*
Return the {@link Command} or {@link Chain} associated with the
* specified name, if any; otherwise, return null.
*
* @param name Name for which a {@link Command} or {@link Chain}
* should be retrieved
* @return The Command associated with the specified name.
*/
Command getCommand(String name);
/**
* Return an Iterator over the set of named commands
* known to this {@link Catalog}. If there are no known commands,
* an empty Iterator is returned.
* @return An iterator of the names in this Catalog.
*/
Iterator getNames();
}