1 /***
2 *
3 * Copyright 2004 Hiram Chirino
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.activeio;
19
20
21 /***
22 * A Channel provides a standard procedure for regulating data transmission between
23 * applications.
24 *
25 * The activeio API encourages that layered wire protocols be created by wiring
26 * together a chain of Channel objects.
27 *
28 * @version $Revision$
29 */
30 public interface Channel extends Disposable, Service {
31
32 /***
33 * Since a Channel may be composed from a chain of other Channel obejcts,
34 * this method allows you to query the chain for the specified {@param target} interface.
35 *
36 * The first Channel in the chain the implments the requested interface will be return
37 * an implementing object. If no Channel in the chain implements the requested class,
38 * then null is returned.
39 */
40 Object narrow(Class target);
41 }