1 //
2 // ========================================================================
3 // Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
8 //
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
11 //
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
14 //
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
17 //
18
19 package org.eclipse.jetty.osgi.boot.internal.webapp;
20
21 import java.io.File;
22 import java.net.MalformedURLException;
23 import java.net.URL;
24 import java.net.URLClassLoader;
25 import java.util.ArrayList;
26 import java.util.HashMap;
27 import java.util.HashSet;
28 import java.util.List;
29 import java.util.Map;
30 import java.util.Set;
31
32 import org.eclipse.jetty.server.Server;
33
34 /**
35 * Helper to create a URL class-loader with the jars inside
36 * ${jetty.home}/lib/ext and ${jetty.home}/resources. In an ideal world, every
37 * library is an OSGi bundle that does loads nicely. To support standard jars or
38 * bundles that cannot be loaded in the current OSGi environment, we support
39 * inserting the jars in the usual jetty/lib/ext folders in the proper classpath
40 * for the webapps.
41 * <p>
42 * Also the folder resources typically contains central configuration files for
43 * things like: log config and others. We enable fragments to register classes
44 * that are called back and passed those resources to do what they need to do.
45 * </p>
46 * <p>
47 * For example the test-jndi webapplication depends on derby, derbytools,
48 * atomikos none of them are osgi bundles. we can either re-package them or we
49 * can place them in the usual lib/ext. <br/>
50 * In fact jasper's jsp libraries should maybe place in lib/ext too.
51 * </p>
52 * <p>
53 * The drawback is that those libraries will not be available in the OSGi
54 * classloader. Note that we could have setup those jars as embedded jars of the
55 * current bundle. However, we would need to know in advance what are those jars
56 * which was not acceptable. Also having those jars in a URLClassLoader seem to
57 * be required for some cases. For example jaspers' TldLocationsCache (replaced
58 * by TldScanner for servlet-3.0). <br/>
59 * Also all the dependencies of those libraries must be resolvable directly from
60 * the JettyBootstrapActivator bundle as it is set as the parent classloader. For
61 * example: if atomikos is placed in lib/ext it will work if and only if
62 * JettyBootstrapActivator import the necessary packages from javax.naming*,
63 * javax.transaction*, javax.mail* etc Most of the common cases of javax are
64 * added as optional import packages into jetty bootstrapper plugin. When there
65 * are not covered: please make a request or create a fragment or register a
66 * bundle with a buddy-policy onto the jetty bootstrapper..
67 * </p>
68 * <p>
69 * Alternatives to placing jars in lib/ext
70 * <ol>
71 * <li>Bundle the jars in an osgi bundle. Have the webapp(s) that context
72 * depends on them depend on that bundle. Things will go well for jetty.</li>
73 * <li>Bundle those jars in an osgi bundle-fragment that targets the
74 * jetty-bootstrap bundle</li>
75 * <li>Use equinox Buddy-Policy: register a buddy of the jetty bootstrapper
76 * bundle. (least favorite: it will work only on equinox)</li>
77 * </ol>
78 * </p>
79 */
80 public class LibExtClassLoaderHelper
81 {
82
83 /**
84 * Class called back
85 */
86 public interface IFilesInJettyHomeResourcesProcessor
87 {
88 void processFilesInResourcesFolder(File jettyHome, Map<String, File> filesInResourcesFolder);
89 }
90
91 public static Set<IFilesInJettyHomeResourcesProcessor> registeredFilesInJettyHomeResourcesProcessors = new HashSet<IFilesInJettyHomeResourcesProcessor>();
92
93 /**
94 * @param server
95 * @return a url classloader with the jars of resources, lib/ext and the
96 * jars passed in the other argument. The parent classloader usually
97 * is the JettyBootStrapper (an osgi classloader.
98 * @throws MalformedURLException
99 */
100 public static ClassLoader createLibEtcClassLoader(File jettyHome, Server server, ClassLoader parentClassLoader) throws MalformedURLException
101 {
102 if (jettyHome == null) { return parentClassLoader; }
103 ArrayList<URL> urls = new ArrayList<URL>();
104 File jettyResources = new File(jettyHome, "resources");
105 if (jettyResources.exists())
106 {
107 // make sure it contains something else than README:
108 Map<String, File> jettyResFiles = new HashMap<String, File>();
109 for (File f : jettyResources.listFiles())
110 {
111 jettyResFiles.put(f.getName(), f);
112 if (f.getName().toLowerCase().startsWith("readme"))
113 {
114 continue;
115 }
116 else
117 {
118 if (urls.isEmpty())
119 {
120 urls.add(jettyResources.toURI().toURL());
121 }
122 }
123 }
124 processFilesInResourcesFolder(jettyHome, jettyResFiles);
125 }
126 File libExt = new File(jettyHome, "lib/ext");
127 if (libExt.exists())
128 {
129 for (File f : libExt.listFiles())
130 {
131 if (f.getName().endsWith(".jar"))
132 {
133 // cheap to tolerate folders so let's do it.
134 URL url = f.toURI().toURL();
135 if (f.isFile())
136 {// is this necessary anyways?
137 url = new URL("jar:" + url.toString() + "!/");
138 }
139 urls.add(url);
140 }
141 }
142 }
143
144 return new URLClassLoader(urls.toArray(new URL[urls.size()]), parentClassLoader);
145 }
146
147 /**
148 * @param server
149 * @return a url classloader with the jars of resources, lib/ext and the
150 * jars passed in the other argument. The parent classloader usually
151 * is the JettyBootStrapper (an osgi classloader). If there was no
152 * extra jars to insert, then just return the parentClassLoader.
153 * @throws MalformedURLException
154 */
155 public static ClassLoader createLibExtClassLoader(List<File> jarsContainerOrJars, List<URL> otherJarsOrFolder, Server server, ClassLoader parentClassLoader)
156 throws MalformedURLException
157 {
158 if (jarsContainerOrJars == null && otherJarsOrFolder == null) { return parentClassLoader; }
159 List<URL> urls = new ArrayList<URL>();
160 if (otherJarsOrFolder != null)
161 {
162 urls.addAll(otherJarsOrFolder);
163 }
164 if (jarsContainerOrJars != null)
165 {
166 for (File libExt : jarsContainerOrJars)
167 {
168 if (libExt.isDirectory())
169 {
170 for (File f : libExt.listFiles())
171 {
172 if (f.getName().endsWith(".jar"))
173 {
174 // cheap to tolerate folders so let's do it.
175 URL url = f.toURI().toURL();
176 if (f.isFile())
177 {
178 // is this necessary anyways?
179 url = new URL("jar:" + url.toString() + "!/");
180 }
181 urls.add(url);
182 }
183 }
184 }
185 }
186 }
187 return new URLClassLoader(urls.toArray(new URL[urls.size()]), parentClassLoader);
188 }
189
190 /**
191 * When we find files typically used for central logging configuration we do
192 * what it takes in this method to do what the user expects. Without
193 * depending too much directly on a particular logging framework.
194 * <p>
195 * We can afford to do some implementation specific code for a logging
196 * framework only in a fragment. <br/>
197 * Trying to configure log4j and logback in here.
198 * </p>
199 * <p>
200 * We recommend that slf4j jars are all placed in the osgi framework. And a
201 * single implementation if possible packaged as an osgi bundle is there.
202 * </p>
203 */
204 protected static void processFilesInResourcesFolder(File jettyHome, Map<String, File> childrenFiles)
205 {
206 for (IFilesInJettyHomeResourcesProcessor processor : registeredFilesInJettyHomeResourcesProcessors)
207 {
208 processor.processFilesInResourcesFolder(jettyHome, childrenFiles);
209 }
210 }
211
212 }