Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
Pipeline |
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| 1.0;1 |
1 | package org.apache.turbine.pipeline; | |
2 | ||
3 | ||
4 | /* | |
5 | * Licensed to the Apache Software Foundation (ASF) under one | |
6 | * or more contributor license agreements. See the NOTICE file | |
7 | * distributed with this work for additional information | |
8 | * regarding copyright ownership. The ASF licenses this file | |
9 | * to you under the Apache License, Version 2.0 (the | |
10 | * "License"); you may not use this file except in compliance | |
11 | * with the License. You may obtain a copy of the License at | |
12 | * | |
13 | * http://www.apache.org/licenses/LICENSE-2.0 | |
14 | * | |
15 | * Unless required by applicable law or agreed to in writing, | |
16 | * software distributed under the License is distributed on an | |
17 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
18 | * KIND, either express or implied. See the License for the | |
19 | * specific language governing permissions and limitations | |
20 | * under the License. | |
21 | */ | |
22 | ||
23 | ||
24 | import java.io.IOException; | |
25 | ||
26 | import org.apache.turbine.util.TurbineException; | |
27 | ||
28 | /** | |
29 | * The idea of a pipeline is being taken from Catalina | |
30 | * in its entirety :-) | |
31 | * | |
32 | * I would like to take the idea further and implement | |
33 | * Valves instead of hardcoding particular methods | |
34 | * in a pipeline. | |
35 | * | |
36 | * It would be more flexible to specify Valves for | |
37 | * a pipeline in an XML file (we can also rip off the | |
38 | * digester rules from T4) and have invoke() as part | |
39 | * of the interface. | |
40 | * | |
41 | * So a set of Valves would be added to the pipeline | |
42 | * and the pipeline would 'invoke' each valve. In the | |
43 | * case Turbine each Valve would produce some output | |
44 | * to be sent out the pipe. I think with another days | |
45 | * work this can be fully working. The first pipeline | |
46 | * to be fully implemented will the ClassicPipeline | |
47 | * will emulate the Turbine 2.1 way of doing things. | |
48 | * | |
49 | * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> | |
50 | * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a> | |
51 | * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a> | |
52 | */ | |
53 | public interface Pipeline | |
54 | { | |
55 | /** | |
56 | * Initializes this instance. Called once by the Turbine servlet. | |
57 | * @throws Exception if the initialization fails | |
58 | */ | |
59 | void initialize() | |
60 | throws Exception; | |
61 | ||
62 | /** | |
63 | * <p>Add a new Valve to the end of the pipeline.</p> | |
64 | * | |
65 | * @param valve Valve to be added. | |
66 | * | |
67 | * @throws IllegalStateException If the pipeline has not been | |
68 | * initialized. | |
69 | */ | |
70 | void addValve(Valve valve); | |
71 | ||
72 | /** | |
73 | * Return the set of all Valves in the pipeline. If there are no | |
74 | * such Valves, a zero-length array is returned. | |
75 | * | |
76 | * @return An array of valves. | |
77 | */ | |
78 | Valve[] getValves(); | |
79 | ||
80 | /** | |
81 | * <p>Cause the specified request and response to be processed by | |
82 | * the sequence of Valves associated with this pipeline, until one | |
83 | * of these Valves decides to end the processing.</p> | |
84 | * | |
85 | * <p>The implementation must ensure that multiple simultaneous | |
86 | * requests (on different threads) can be processed through the | |
87 | * same Pipeline without interfering with each other's control | |
88 | * flow.</p> | |
89 | * | |
90 | * @param pipelineData The run-time information, including the servlet | |
91 | * request and response we are processing. | |
92 | * @throws TurbineException if the invocation fails | |
93 | * @throws IOException an input/output error occurred. | |
94 | */ | |
95 | void invoke(PipelineData pipelineData) | |
96 | throws TurbineException, IOException; | |
97 | ||
98 | /** | |
99 | * Remove the specified Valve from the pipeline, if it is found; | |
100 | * otherwise, do nothing. | |
101 | * | |
102 | * @param valve Valve to be removed. | |
103 | */ | |
104 | void removeValve(Valve valve); | |
105 | } |