Catalog


1   /*
2    * Copyright 2003-2004 The Apache Software Foundation
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.commons.chain;
17  
18  
19  import java.util.Iterator  ;
20  
21  
22  /**
23   * <p>A {@link Catalog} is a collection of named {@link Command}s (or
24   * {@link Chain}s) that can be used retrieve the set of commands that
25   * should be performed based on a symbolic identifier.  Use of catalogs
26   * is optional, but convenient when there are multiple possible chains
27   * that can be selected and executed based on environmental conditions.</p>
28   *
29   * @author Craig R. McClanahan
30   * @version $Revision: 1.7 $ $Date: 2004/11/30 05:52:22 $
31   */
32  
33  public interface Catalog {
34  
35  
36      /**
37       * <p>A default context attribute for storing a default {@link Catalog},
38       * provided as a convenience only.</p>
39       */
40      String   CATALOG_KEY = "org.apache.commons.chain.CATALOG";
41  
42  
43      /**
44       * <p>Add a new name and associated {@link Command} or {@link Chain}
45       * to the set of named commands known to this {@link Catalog},
46       * replacing any previous command for that name.
47       *
48       * @param name Name of the new command
49       * @param command {@link Command} or {@link Chain} to be returned
50       *  for later lookups on this name
51       */
52      void addCommand(String   name, Command command);
53  
54  
55      /**
56       * <p>Return the {@link Command} or {@link Chain} associated with the
57       * specified name, if any; otherwise, return <code>null</code>.</p>
58       *
59       * @param name Name for which a {@link Command} or {@link Chain}
60       *  should be retrieved
61       */
62      Command getCommand(String   name);
63  
64  
65  
66      /**
67       * <p>Return an <code>Iterator</code> over the set of named commands
68       * known to this {@link Catalog}.  If there are no known commands,
69       * an empty Iterator is returned.</p>
70       */
71      Iterator   getNames();
72  
73  
74  }
75  
76
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags