1 package org.apache.turbine.pipeline;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.io.IOException;
23 import java.util.Iterator;
24 import java.util.concurrent.CopyOnWriteArrayList;
25
26 import javax.xml.bind.annotation.XmlAccessType;
27 import javax.xml.bind.annotation.XmlAccessorType;
28 import javax.xml.bind.annotation.XmlAttribute;
29 import javax.xml.bind.annotation.XmlElement;
30 import javax.xml.bind.annotation.XmlElementWrapper;
31 import javax.xml.bind.annotation.XmlRootElement;
32 import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
33
34 import org.apache.turbine.annotation.AnnotationProcessor;
35 import org.apache.turbine.util.TurbineException;
36
37 /**
38 * Flexible implementation of a {@link org.apache.turbine.pipeline.Pipeline}.
39 * Originally based on code from Catalina and ideas from Apache httpd.
40 *
41 * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
42 * @author <a href="mailto:jvanzyl@zenplex.com">Jason van Zyl</a>
43 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
44 */
45 @XmlRootElement(name="pipeline")
46 @XmlAccessorType(XmlAccessType.NONE)
47 public class TurbinePipeline
48 implements Pipeline, ValveContext
49 {
50 /**
51 * The "Turbine Classic" pipeline.
52 */
53 public static final String CLASSIC_PIPELINE =
54 "/WEB-INF/conf/turbine-classic-pipeline.xml";
55
56 /**
57 * Name of this pipeline.
58 */
59 @XmlAttribute
60 private String name;
61
62 /**
63 * The set of Valves associated with this Pipeline.
64 */
65 private CopyOnWriteArrayList<Valve> valves = new CopyOnWriteArrayList<>();
66
67 /**
68 * The per-thread execution state for processing through this pipeline.
69 */
70 private ThreadLocal<Iterator<Valve>> state = new ThreadLocal<>();
71
72 /**
73 * @see org.apache.turbine.pipeline.Pipeline#initialize()
74 */
75 @Override
76 public void initialize()
77 throws Exception
78 {
79 // Valve implementations are added to this Pipeline using the
80 // Mapper.
81
82 // Initialize the valves
83 for (Valve v : valves)
84 {
85 AnnotationProcessor.process(v);
86 v.initialize();
87 }
88 }
89
90 /**
91 * Set the name of this pipeline.
92 *
93 * @param name
94 * Name of this pipeline.
95 */
96 public void setName(String name)
97 {
98 this.name = name;
99 }
100
101 /**
102 * Get the name of this pipeline.
103 *
104 * @return String Name of this pipeline.
105 */
106 public String getName()
107 {
108 return name;
109 }
110
111 /**
112 * @see org.apache.turbine.pipeline.Pipeline#addValve(Valve)
113 */
114 @Override
115 public void addValve(Valve valve)
116 {
117 // Add this Valve to the end of the set associated with this Pipeline
118 valves.add(valve);
119 }
120
121 /**
122 * @see org.apache.turbine.pipeline.Pipeline#getValves()
123 */
124 @Override
125 @XmlElementWrapper(name="valves")
126 @XmlElement(name="valve")
127 @XmlJavaTypeAdapter(XmlValveAdapter.class)
128 public Valve[] getValves()
129 {
130 return valves.toArray(new Valve[0]);
131 }
132
133 /**
134 * Set new valves during deserialization
135 *
136 * @param valves the valves to set
137 */
138 protected void setValves(Valve[] valves)
139 {
140 this.valves = new CopyOnWriteArrayList<>(valves);
141 }
142
143 /**
144 * @see org.apache.turbine.pipeline.Pipeline#removeValve(Valve)
145 */
146 @Override
147 public void removeValve(Valve valve)
148 {
149 valves.remove(valve);
150 }
151
152 /**
153 * @see org.apache.turbine.pipeline.Pipeline#invoke(PipelineData)
154 */
155 @Override
156 public void invoke(PipelineData pipelineData)
157 throws TurbineException, IOException
158 {
159 // Initialize the per-thread state for this thread
160 state.set(valves.iterator());
161
162 // Invoke the first Valve in this pipeline for this request
163 invokeNext(pipelineData);
164 }
165
166 /**
167 * @see org.apache.turbine.pipeline.ValveContext#invokeNext(PipelineData)
168 */
169 @Override
170 public void invokeNext(PipelineData pipelineData)
171 throws TurbineException, IOException
172 {
173 // Identify the current valve for the current request thread
174 Iterator<Valve> current = state.get();
175
176 if (current.hasNext())
177 {
178 // Invoke the requested Valve for the current request
179 // thread and increment its thread-local state.
180 current.next().invoke(pipelineData, this);
181 }
182 }
183 }