1 /*
2 * Copyright 2012-2013 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.properties.spi.core.classpath;
17
18 import java.net.URL;
19 import java.net.URLClassLoader;
20 import java.util.Collection;
21 import java.util.Collections;
22 import java.util.Iterator;
23 import java.util.Set;
24 import java.util.regex.Pattern;
25
26 import org.reflections.Reflections;
27 import org.reflections.scanners.ResourcesScanner;
28 import org.reflections.util.ConfigurationBuilder;
29
30 import de.smartics.properties.api.core.domain.PropertiesContext;
31
32 /**
33 * Loads properties files found on the class path.
34 */
35 public final class PropertiesFilesLoader
36 {
37 // ********************************* Fields *********************************
38
39 // --- constants ------------------------------------------------------------
40
41 /**
42 * Pattern to filter properties files.
43 * <p>
44 * Every properties file (with file extension <code>properties</code> is
45 * allowed as long as the name does not contain any underscores. Underscores
46 * are used to distinguish localized information (like
47 * <code>my-properties_en.properties</code>) and therefore must not
48 * considered.
49 * </p>
50 *
51 * @impl Note that the pattern here is only the file name pattern without a
52 * path.
53 */
54 private static final Pattern PROPERTIES_PATTERN = Pattern
55 .compile("[^_]+\\.properties");
56
57 /**
58 * Pattern to detect boot properties files.
59 *
60 * @impl Note that the pattern here is only the file name pattern without a
61 * path.
62 */
63 private static final Pattern BOOT_PROPERTIES_PATTERN = Pattern
64 .compile("boot\\.properties");
65
66 /**
67 * Default scanner to use.
68 */
69 private static final ResourcesScanner SCANNER = new ResourcesScanner();
70
71 // --- members --------------------------------------------------------------
72
73 // ****************************** Initializer *******************************
74
75 // ****************************** Constructors ******************************
76
77 // ****************************** Inner Classes *****************************
78
79 // ********************************* Methods ********************************
80
81 // --- init -----------------------------------------------------------------
82
83 private static Reflections buildReflections(final Collection<URL> urls)
84 {
85 final ClassLoader classLoader =
86 new URLClassLoader(urls.toArray(new URL[urls.size()]), Thread
87 .currentThread().getContextClassLoader());
88
89 final ConfigurationBuilder builder = new ConfigurationBuilder();
90 builder.addScanners(SCANNER).addClassLoader(classLoader).addUrls(urls);
91 final Reflections reflections = new Reflections(builder);
92 return reflections;
93 }
94
95 // --- get&set --------------------------------------------------------------
96
97 // --- business -------------------------------------------------------------
98
99 /**
100 * Returns all files with the extension <code>.properties</code>.
101 *
102 * @param urls the class roots to search for files that have the
103 * <code>.properties</code> file name extension.
104 * @return the names of properties files relative to the class path root.
105 */
106 public Set<String> getPropertiesFiles(final Collection<URL> urls)
107 {
108 if (urls == null || urls.isEmpty())
109 {
110 return Collections.emptySet();
111 }
112
113 final Reflections reflections = buildReflections(urls);
114 final Set<String> pathes = reflections.getResources(PROPERTIES_PATTERN);
115
116 return pathes;
117 }
118
119 /**
120 * Returns all boot properties that are defined to control the configuration
121 * parsing process. Properties are stored in files matching
122 * <code>/{@value de.smartics.properties.api.core.domain.PropertiesContext#META_INF_HOME}/boot.properties</code>
123 * .
124 *
125 * @param urls the URLs to search in.
126 * @return the names of properties files relative to the class path root.
127 */
128 public Set<String> getBootPropertiesFiles(final Collection<URL> urls)
129 {
130 if (urls == null || urls.isEmpty())
131 {
132 return Collections.emptySet();
133 }
134
135 final Reflections reflections = buildReflections(urls);
136 final Set<String> pathes =
137 reflections.getResources(BOOT_PROPERTIES_PATTERN);
138
139 for (final Iterator<String> i = pathes.iterator(); i.hasNext();)
140 {
141 final String path = i.next();
142 if (!path.endsWith(PropertiesContext.META_INF_HOME + "/boot.properties"))
143 {
144 i.remove();
145 }
146 }
147
148 return pathes;
149 }
150
151 // --- object basics --------------------------------------------------------
152
153 }