1 /*
2 * Copyright 2008-2013 smartics, Kronseder & Reiner GmbH
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package de.smartics.maven.issues.cache;
17
18 import java.io.File;
19 import java.io.InputStream;
20 import java.io.OutputStream;
21
22 import javax.xml.stream.XMLInputFactory;
23 import javax.xml.stream.XMLOutputFactory;
24 import javax.xml.stream.XMLStreamException;
25 import javax.xml.stream.XMLStreamReader;
26 import javax.xml.stream.XMLStreamWriter;
27
28 import org.apache.commons.logging.Log;
29 import org.apache.commons.logging.LogFactory;
30 import org.eclipse.mylyn.tasks.core.data.TaskData;
31
32 /**
33 * Implementation of the data store that writes task data to XML files.
34 *
35 * @author <a href="mailto:robert.reiner@smartics.de">Robert Reiner</a>
36 * @version $Revision:591 $
37 */
38 public class XmlTaskDataStore extends AbstractFileTaskDataStore
39 {
40 // ********************************* Fields *********************************
41
42 // --- constants ------------------------------------------------------------
43
44 /**
45 * Reference to the logger for this class.
46 */
47 private static final Log LOG = LogFactory.getLog(XmlTaskDataStore.class);
48
49 // --- members --------------------------------------------------------------
50
51 // ****************************** Initializer *******************************
52
53 // ****************************** Constructors ******************************
54
55 /**
56 * Default constructor.
57 *
58 * @param persistentStoreDirectory the reference to the directory to store the
59 * individual task files.
60 */
61 public XmlTaskDataStore(final File persistentStoreDirectory)
62 {
63 super(persistentStoreDirectory, ".xml");
64 }
65
66 // ****************************** Inner Classes *****************************
67
68 // ********************************* Methods ********************************
69
70 // --- init -----------------------------------------------------------------
71
72 // --- get&set --------------------------------------------------------------
73
74 // --- business -------------------------------------------------------------
75
76 /**
77 * Reads the task from the given input stream.
78 *
79 * @param inputStream the input stream to read from.
80 * @return the task information read from the given input stream.
81 * @throws PersistenceException if the task data cannot be read from the given
82 * input stream.
83 */
84 protected TaskData readTask(final InputStream inputStream)
85 throws PersistenceException
86 {
87 final XMLInputFactory factory = XMLInputFactory.newInstance();
88 XMLStreamReader xmlReader = null;
89 try
90 {
91 xmlReader = factory.createXMLStreamReader(inputStream);
92 final XmlTaskReader taskReader = new XmlTaskReader(xmlReader);
93 return taskReader.readTask();
94 }
95 catch (final XMLStreamException e)
96 {
97 throw new PersistenceException("Cannot read task from XML stream.", e);
98 }
99 finally
100 {
101 if (xmlReader != null)
102 {
103 try
104 {
105 xmlReader.close();
106 }
107 catch (final XMLStreamException e)
108 {
109 // Ignore
110 if (LOG.isErrorEnabled())
111 {
112 LOG.error("Cannot close input stream. Continue...", e);
113 }
114 }
115 }
116 }
117 }
118
119 /**
120 * Persists the task to the given output stream. This method takes
121 * responsibility of closing the stream.
122 *
123 * @param outputStream the output stream to write to.
124 * @param task the task data to store.
125 * @throws PersistenceException if the task data cannot be written to the
126 * given output stream.
127 */
128 protected void writeTask(final OutputStream outputStream, final TaskData task)
129 throws PersistenceException
130 {
131 final XMLOutputFactory factory = XMLOutputFactory.newInstance();
132 XMLStreamWriter xmlWriter = null;
133 try
134 {
135 xmlWriter = factory.createXMLStreamWriter(outputStream);
136 xmlWriter.writeStartDocument();
137 final XmlTaskWriter taskWriter = new XmlTaskWriter(xmlWriter);
138 taskWriter.writeTask(task);
139 xmlWriter.writeEndDocument();
140 }
141 catch (final XMLStreamException e)
142 {
143 final String message =
144 "Cannot persist task data with ID '" + task.getTaskId() + "'.";
145 LOG.warn(message, e);
146 throw new PersistenceException(message, e);
147 }
148 finally
149 {
150 if (xmlWriter != null)
151 {
152 try
153 {
154 xmlWriter.close();
155 }
156 catch (final XMLStreamException e)
157 {
158 // Ignore
159 if (LOG.isErrorEnabled())
160 {
161 LOG.error("Cannot close output stream. Continue...", e);
162 }
163 }
164 }
165 }
166 }
167
168 // --- object basics --------------------------------------------------------
169
170 }