Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
ProtocolChain |
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| 1.0;1 |
1 | /* | |
2 | * | |
3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. | |
4 | * | |
5 | * Copyright 2007-2008 Sun Microsystems, Inc. All rights reserved. | |
6 | * | |
7 | * The contents of this file are subject to the terms of either the GNU | |
8 | * General Public License Version 2 only ("GPL") or the Common Development | |
9 | * and Distribution License("CDDL") (collectively, the "License"). You | |
10 | * may not use this file except in compliance with the License. You can obtain | |
11 | * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html | |
12 | * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific | |
13 | * language governing permissions and limitations under the License. | |
14 | * | |
15 | * When distributing the software, include this License Header Notice in each | |
16 | * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt. | |
17 | * Sun designates this particular file as subject to the "Classpath" exception | |
18 | * as provided by Sun in the GPL Version 2 section of the License file that | |
19 | * accompanied this code. If applicable, add the following below the License | |
20 | * Header, with the fields enclosed by brackets [] replaced by your own | |
21 | * identifying information: "Portions Copyrighted [year] | |
22 | * [name of copyright owner]" | |
23 | * | |
24 | * Contributor(s): | |
25 | * | |
26 | * If you wish your version of this file to be governed by only the CDDL or | |
27 | * only the GPL Version 2, indicate your decision by adding "[Contributor] | |
28 | * elects to include this software in this distribution under the [CDDL or GPL | |
29 | * Version 2] license." If you don't indicate a single choice of license, a | |
30 | * recipient has the option to distribute your version of this file under | |
31 | * either the CDDL, the GPL Version 2 or to extend the choice of license to | |
32 | * its licensees as provided above. However, if you add GPL Version 2 code | |
33 | * and therefore, elected the GPL Version 2 license, then the option applies | |
34 | * only if the new code is made subject to such option by the copyright | |
35 | * holder. | |
36 | * | |
37 | */ | |
38 | ||
39 | package com.sun.grizzly; | |
40 | ||
41 | /** | |
42 | * <p> | |
43 | * This class implement the "Chain of Responsibility" pattern (for more info, | |
44 | * take a look at the classic "Gang of Four" design patterns book). Towards | |
45 | * that end, the Chain API models a computation as a series of "protocol filter" | |
46 | * that can be combined into a "protocol chain". | |
47 | * </p><p> | |
48 | * The API for ProtocolFilter consists of a two methods (execute() and | |
49 | * postExecute) which is passed a "protocol context" parameter containing the | |
50 | * dynamic state of the computation, and whose return value is a boolean | |
51 | * that determines whether or not processing for the current chain has been | |
52 | * completed (false), or whether processing should be delegated to the next | |
53 | * ProtocolFilter in the chain (true). The owning ProtocolChain must call the | |
54 | * postExectute() method of each ProtocolFilter in a ProtocolChain in reverse | |
55 | * order of the invocation of their execute() methods. | |
56 | * </p><p> | |
57 | * The following picture describe how it ProtocolFilter(s) | |
58 | * </p><p><pre><code> | |
59 | * ----------------------------------------------------------------------------- | |
60 | * - ProtocolFilter1.execute() --> ProtocolFilter2.execute() -------| - | |
61 | * - | - | |
62 | * - | - | |
63 | * - | - | |
64 | * - ProtocolFilter1.postExecute() <-- ProtocolFilter2.postExecute()| - | |
65 | * ----------------------------------------------------------------------------- | |
66 | * </code></pre></p><p> | |
67 | * The "context" abstraction is designed to isolate ProtocolFilter | |
68 | * implementations from the environment in which they are run | |
69 | * (such as a ProtocolFilter that can be used in either IIOP or HTTP parsing, | |
70 | * without being tied directly to the API contracts of either of these | |
71 | * environments). For ProtocolFilter that need to allocate resources prior to | |
72 | * delegation, and then release them upon return (even if a delegated-to | |
73 | * ProtocolFilter throws an exception), the "postExecute" method can be used | |
74 | * for cleanup. | |
75 | * </p> | |
76 | * @author Jeanfrancois Arcand | |
77 | */ | |
78 | public interface ProtocolChain{ | |
79 | ||
80 | /** | |
81 | * Add a {@link ProtocolFilter} to the list. {@link ProtocolFilter} | |
82 | * will be invoked in the order they have been added. | |
83 | * @param protocolFilter {@link ProtocolFilter} | |
84 | * @return {@link ProtocolFilter} added successfully (yes/no) ? | |
85 | */ | |
86 | public boolean addFilter(ProtocolFilter protocolFilter); | |
87 | ||
88 | ||
89 | /** | |
90 | * Remove the {@link ProtocolFilter} from this chain. | |
91 | * @param theFilter {@link ProtocolFilter} | |
92 | * @return {@link ProtocolFilter} removed successfully (yes/no) ? | |
93 | */ | |
94 | public boolean removeFilter(ProtocolFilter theFilter); | |
95 | ||
96 | ||
97 | /** | |
98 | * Insert a {@link ProtocolFilter} to the list at position 'pos'. | |
99 | * @param pos The insertion position | |
100 | * @param protocolFilter {@link ProtocolFilter} | |
101 | */ | |
102 | public void addFilter(int pos, ProtocolFilter protocolFilter); | |
103 | ||
104 | ||
105 | /** | |
106 | * Execute using the {@link Context} instance. | |
107 | * @param context <code>Context<code> | |
108 | * @throws java.lang.Exception | |
109 | */ | |
110 | public void execute(Context context) throws Exception; | |
111 | ||
112 | ||
113 | } |