1 /*
2 * $Id: CompositeActionMapper.java 791919 2009-07-07 17:47:34Z musachy $
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 package org.apache.struts2.dispatcher.mapper;
23
24 import java.util.ArrayList;
25 import java.util.List;
26
27 import javax.servlet.http.HttpServletRequest;
28
29 import org.apache.struts2.StrutsConstants;
30
31 import com.opensymphony.xwork2.config.ConfigurationManager;
32 import com.opensymphony.xwork2.inject.Container;
33 import com.opensymphony.xwork2.inject.Inject;
34 import com.opensymphony.xwork2.util.logging.Logger;
35 import com.opensymphony.xwork2.util.logging.LoggerFactory;
36
37 /**
38 * <!-- START SNIPPET: description -->
39 *
40 * A composite action mapper that is capable of delegating to a series of {@link ActionMapper} if the former
41 * failed to obtained a valid {@link ActionMapping} or uri.
42 * <p/>
43 * It is configured through struts.properties.
44 * <p/>
45 * For example, with the following entries in struts.properties
46 * <p/>
47 * <pre>
48 * <bean type="org.apache.struts2.dispatcher.mapper.ActionMapper" name="struts"
49 * class="org.apache.struts2.dispatcher.mapper.CompositeActionMapper" />
50 * <constant name="struts.mapper.composite"
51 * value="org.apache.struts2.dispatcher.mapper.DefaultActionMapper,org.apache.struts2.dispatcher.mapper.RestfulActionMapper,org.apache.struts2.dispatcher.mapper.Restful2ActionMapper" />
52 * </pre>
53 * <p/>
54 * When {@link CompositeActionMapper#getMapping(HttpServletRequest, ConfigurationManager)} or
55 * {@link CompositeActionMapper#getUriFromActionMapping(ActionMapping)} is invoked,
56 * {@link CompositeActionMapper} would go through these {@link ActionMapper}s in sequence
57 * starting from {@link ActionMapper} identified by 'struts.mapper.composite.1', followed by
58 * 'struts.mapper.composite.2' and finally 'struts.mapper.composite.3' (in this case) until either
59 * one of the {@link ActionMapper} return a valid result (not null) or it runs out of {@link ActionMapper}
60 * in which case it will just return null for both
61 * {@link CompositeActionMapper#getMapping(HttpServletRequest, ConfigurationManager)} and
62 * {@link CompositeActionMapper#getUriFromActionMapping(ActionMapping)} methods.
63 * <p/>
64 *
65 * For example with the following in struts-*.xml :-
66 * <pre>
67 * <bean type="org.apache.struts2.dispatcher.mapper.ActionMapper" name="struts"
68 * class="org.apache.struts2.dispatcher.mapper.CompositeActionMapper" />
69 * <constant name="struts.mapper.composite"
70 * value="org.apache.struts2.dispatcher.mapper.DefaultActionMapper,foo.bar.MyActionMapper,foo.bar.MyAnotherActionMapper" />
71 * </pre>
72 * <p/>
73 * <code>CompositeActionMapper</code> will be configured with 3 ActionMapper, namely
74 * "DefaultActionMapper", "MyActionMapper" and "MyAnotherActionMapper".
75 * <code>CompositeActionMapper</code> would consult each of them in order described above.
76 *
77 * <!-- END SNIPPET: description -->
78 *
79 * @see ActionMapper
80 * @see ActionMapping
81 *
82 * @version $Date: 2009-07-07 13:47:34 -0400 (Tue, 07 Jul 2009) $ $Id: CompositeActionMapper.java 791919 2009-07-07 17:47:34Z musachy $
83 */
84 public class CompositeActionMapper implements ActionMapper {
85
86 private static final Logger LOG = LoggerFactory.getLogger(CompositeActionMapper.class);
87
88 protected Container container;
89
90 protected List<ActionMapper> actionMappers = new ArrayList<ActionMapper>();
91
92 @Inject
93 public void setContainer(Container container) {
94 this.container = container;
95 }
96
97 @Inject(StrutsConstants.STRUTS_MAPPER_COMPOSITE)
98 public void setActionMappers(String list) {
99 if (list != null) {
100 String[] arr = list.split(",");
101 for (String name : arr) {
102 Object obj = container.getInstance(ActionMapper.class, name);
103 if (obj != null) {
104 actionMappers.add((ActionMapper) obj);
105 }
106 }
107 }
108 }
109
110
111 public ActionMapping getMapping(HttpServletRequest request, ConfigurationManager configManager) {
112
113 for (ActionMapper actionMapper : actionMappers) {
114 ActionMapping actionMapping = actionMapper.getMapping(request, configManager);
115 if (LOG.isDebugEnabled()) {
116 LOG.debug("Using ActionMapper "+actionMapper);
117 }
118 if (actionMapping == null) {
119 if (LOG.isDebugEnabled()) {
120 LOG.debug("ActionMapper "+actionMapper+" failed to return an ActionMapping (null)");
121 }
122 }
123 else {
124 return actionMapping;
125 }
126 }
127 if (LOG.isDebugEnabled()) {
128 LOG.debug("exhausted from ActionMapper that could return an ActionMapping");
129 }
130 return null;
131 }
132
133 public ActionMapping getMappingFromActionName(String actionName) {
134
135 for (ActionMapper actionMapper : actionMappers) {
136 ActionMapping actionMapping = actionMapper.getMappingFromActionName(actionName);
137 if (LOG.isDebugEnabled()) {
138 LOG.debug("Using ActionMapper "+actionMapper);
139 }
140 if (actionMapping == null) {
141 if (LOG.isDebugEnabled()) {
142 LOG.debug("ActionMapper "+actionMapper+" failed to return an ActionMapping (null)");
143 }
144 }
145 else {
146 return actionMapping;
147 }
148 }
149 if (LOG.isDebugEnabled()) {
150 LOG.debug("exhausted from ActionMapper that could return an ActionMapping");
151 }
152 return null;
153 }
154
155 public String getUriFromActionMapping(ActionMapping mapping) {
156
157 for (ActionMapper actionMapper : actionMappers) {
158 String uri = actionMapper.getUriFromActionMapping(mapping);
159 if (LOG.isDebugEnabled()) {
160 LOG.debug("Using ActionMapper "+actionMapper);
161 }
162 if (uri == null) {
163 if (LOG.isDebugEnabled()) {
164 LOG.debug("ActionMapper "+actionMapper+" failed to return an ActionMapping (null)");
165 }
166 }
167 else {
168 return uri;
169 }
170 }
171 if (LOG.isDebugEnabled()) {
172 LOG.debug("exhausted from ActionMapper that could return a uri");
173 }
174 return null;
175 }
176 }
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