1 package org.apache.torque.generator.configuration.mergepoint;
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 static org.apache.torque.generator.configuration.mergepoint.MergepointConfigurationTags.ACTION_TAG;
23 import static org.apache.torque.generator.configuration.mergepoint.MergepointConfigurationTags.MERGEPOINT_NAME_ATTRIBUTE;
24 import static org.apache.torque.generator.configuration.mergepoint.MergepointConfigurationTags.MERGEPOINT_TAG;
25
26 import org.apache.torque.generator.configuration.ConfigurationHandlers;
27 import org.apache.torque.generator.configuration.ConfigurationProvider;
28 import org.apache.torque.generator.configuration.XMLConstants;
29 import org.apache.torque.generator.configuration.paths.ProjectPaths;
30 import org.xml.sax.Attributes;
31 import org.xml.sax.SAXException;
32
33 /**
34 * A SAX Handler which processes a mergepoint configuration in an outlet.
35 */
36 public class MergepointSaxHandler
37 {
38 /**
39 * The mergepoint mapping which is created and filled using the
40 * information in the parsed XML element.
41 */
42 private MergepointMapping mergepointMapping;
43
44 /**
45 * The access object for the configuration files, not null.
46 */
47 private ConfigurationProvider configurationProvider;
48
49 /**
50 * The paths of the surrounding project, not null.
51 */
52 private ProjectPaths projectPaths;
53
54 /**
55 * The available configuration handlers.
56 */
57 private ConfigurationHandlers configurationHandlers;
58
59 /**
60 * A SAX handler which parses nested elements. Null if no nested element
61 * is currently parsed.
62 */
63 private ActionSaxHandler delegateHandler;
64
65 /**
66 * Whether the mergepoint element is completely parsed.
67 */
68 private boolean finished = false;
69
70 /**
71 * Constructor.
72 *
73 * @param configurationProvider The access object for the configuration
74 * files, not null.
75 * @param projectPaths The paths of the surrounding project, not null.
76 * @param configurationHandlers the available configuration handlers,
77 * not null.
78 *
79 * @throws NullPointerException if an argument is null.
80 */
81 public MergepointSaxHandler(
82 ConfigurationProvider configurationProvider,
83 ProjectPaths projectPaths,
84 ConfigurationHandlers configurationHandlers)
85 {
86 if (configurationProvider == null)
87 {
88 throw new NullPointerException(
89 "configurationProvider must not be null");
90 }
91 if (projectPaths == null)
92 {
93 throw new NullPointerException("projectPaths must not be null");
94 }
95 if (configurationHandlers == null)
96 {
97 throw new NullPointerException(
98 "configurationHandlers must not be null");
99 }
100 this.configurationProvider = configurationProvider;
101 this.projectPaths = projectPaths;
102 this.configurationHandlers = configurationHandlers;
103 }
104
105 /**
106 * Returns the mergepointMapping configured by this SaxHandler.
107 * If this method is called before the mergepoint tag has been processed
108 * completely, it will throw an IllegalStateException.
109 *
110 * @return the complete mergepointMapping, never null.
111 *
112 * @throws IllegalStateException if the mergepoint tag has not been
113 * processed completely.
114 */
115 public MergepointMapping getMergepointMapping()
116 {
117 if (!finished)
118 {
119 throw new IllegalStateException("not finished parsing");
120 }
121 return mergepointMapping;
122 }
123
124 /**
125 * Callback method which is called by the SAX parser if an XML element is
126 * started.
127 * If a known element is encountered, its settings are read and applied to
128 * the mergepoint; if an unknown element is encountered, a SaxException is
129 * thrown.
130 *
131 * @param uri The namespace URI of the started element,
132 * or the empty string if the element has no namespace URI
133 * or if namespace processing is not being performed.
134 * @param localName The local name (without prefix), or
135 * the empty string if Namespace processing is not being performed.
136 * @param qName The qualified name (with prefix, if present),
137 * or the empty string if qualified names are not available.
138 * @param attributes The attributes attached to the element.
139 *
140 * @throws SAXException if an error occurs during parsing.
141 *
142 * @see org.xml.sax.ContentHandler#startElement(String, String, String, Attributes)
143 */
144 public void startElement(
145 String uri,
146 String localName,
147 String qName,
148 Attributes attributes)
149 throws SAXException
150 {
151 if (delegateHandler != null)
152 {
153 delegateHandler.startElement(uri, localName, qName, attributes);
154 }
155 else if (MERGEPOINT_TAG.equals(qName))
156 {
157 String name = attributes.getValue(MERGEPOINT_NAME_ATTRIBUTE);
158 if (name == null)
159 {
160 throw new SAXException("The tag "
161 + MERGEPOINT_TAG
162 + " needs to have the attribute "
163 + MERGEPOINT_NAME_ATTRIBUTE);
164 }
165 mergepointMapping = new MergepointMapping(name);
166 }
167 else if (ACTION_TAG.equals(qName))
168 {
169 String type = attributes.getValue(
170 XMLConstants.XSI_NAMESPACE,
171 XMLConstants.XSI_TYPE_ATTRBUTE_NAME);
172 if (type == null)
173 {
174 throw new SAXException("The tag " + ACTION_TAG
175 + " requires the attribute "
176 + XMLConstants.XSI_NAMESPACE
177 + ":"
178 + XMLConstants.XSI_TYPE_ATTRBUTE_NAME);
179 }
180
181 ActionSaxHandlerFactories actionSaxHandlerFactories
182 = configurationHandlers.getActionSaxHandlerFactories();
183 ActionSaxHandlerFactory handlerFactory
184 = actionSaxHandlerFactories.getActionSaxHandlerFactory(type);
185 if (handlerFactory == null)
186 {
187 throw new SAXException("No handler found for the action "
188 + "of type "
189 + type);
190 }
191
192 delegateHandler = handlerFactory.getActionSaxHandler(
193 uri,
194 localName,
195 qName,
196 attributes,
197 configurationProvider,
198 projectPaths);
199 }
200 else
201 {
202 throw new SAXException("unknown element : " + qName);
203 }
204 }
205
206 /**
207 * Callback method which is called by the SAX parser if an XML element is
208 * ended.
209 * If an action element is ended, the action is added to the action
210 * list for the mergepoint. If the mergepoint element is ended, the parser
211 * marks itself as finished.
212 *
213 * @param uri The namespace URI of the ended element,
214 * or the empty string if the element has no namespace URI
215 * or if namespace processing is not being performed.
216 * @param localName The local name (without prefix), or
217 * the empty string if Namespace processing is not being performed.
218 * @param qName The qualified name (with prefix, if present),
219 * or the empty string if qualified names are not available.
220 *
221 * @see org.xml.sax.ContentHandler#endElement(String, String, String)
222 */
223 public void endElement(String uri, String localName, String qName)
224 {
225 if (ACTION_TAG.equals(qName))
226 {
227 mergepointMapping.addAction(delegateHandler.getAction());
228 delegateHandler = null;
229 }
230 else if (MERGEPOINT_TAG.equals(qName))
231 {
232 finished = true;
233 }
234 }
235
236 /**
237 * Returns whether the parser has finished parsing the mergepoint tag.
238 *
239 * @return true if the parser has finished, false otherwise.
240 */
241 public boolean isFinished()
242 {
243 return finished;
244 }
245 }