001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied. See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019
020 package org.apache.xbean.osgi.bundle.util;
021
022 import java.net.URL;
023 import java.util.Collections;
024 import java.util.Dictionary;
025 import java.util.Enumeration;
026 import java.util.LinkedHashSet;
027 import java.util.List;
028
029 import org.osgi.framework.Bundle;
030 import org.osgi.framework.BundleReference;
031 import org.osgi.framework.Constants;
032 import org.osgi.framework.ServiceReference;
033 import org.osgi.service.packageadmin.ExportedPackage;
034 import org.osgi.service.packageadmin.PackageAdmin;
035
036 /**
037 * @version $Rev: 937957 $ $Date: 2010-04-26 10:00:08 +0200 (Mon, 26 Apr 2010) $
038 */
039 public class BundleUtils {
040
041 public static boolean canStart(Bundle bundle) {
042 return (bundle.getState() != Bundle.UNINSTALLED) && (bundle.getState() != Bundle.STARTING) && (!isFragment(bundle));
043 }
044
045 public static boolean canStop(Bundle bundle) {
046 return (bundle.getState() != Bundle.UNINSTALLED) && (bundle.getState() != Bundle.STOPPING) && (!isFragment(bundle));
047 }
048
049 public static boolean canUninstall(Bundle bundle) {
050 return bundle.getState() != Bundle.UNINSTALLED;
051 }
052
053 public static boolean isFragment(Bundle bundle) {
054 Dictionary headers = bundle.getHeaders();
055 return (headers != null && headers.get(Constants.FRAGMENT_HOST) != null);
056 }
057
058 /**
059 * Returns bundle (if any) associated with current thread's context classloader.
060 *
061 * @param unwrap if true and if the bundle associated with the context classloader is a
062 * {@link DelegatingBundle}, this function will return the main application bundle
063 * backing with the {@link DelegatingBundle}. Otherwise, the bundle associated with
064 * the context classloader is returned as is. See {@link BundleClassLoader#getBundle(boolean)}
065 * for more information.
066 * @return The bundle associated with the current thread's context classloader. Might be null.
067 */
068 public static Bundle getContextBundle(boolean unwrap) {
069 ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
070 if (classLoader instanceof BundleClassLoader) {
071 return ((BundleClassLoader) classLoader).getBundle(unwrap);
072 } else if (classLoader instanceof BundleReference) {
073 return ((BundleReference) classLoader).getBundle();
074 } else {
075 return null;
076 }
077 }
078
079 /**
080 * Works like {@link Bundle#getEntryPaths(String)} but also returns paths
081 * in attached fragment bundles.
082 *
083 * @param bundle
084 * @param name
085 * @return
086 */
087 public static Enumeration<String> getEntryPaths(Bundle bundle, String name) {
088 Enumeration<URL> entries = bundle.findEntries(name, null, false);
089 if (entries == null) {
090 return null;
091 }
092 LinkedHashSet<String> paths = new LinkedHashSet<String>();
093 while (entries.hasMoreElements()) {
094 URL url = entries.nextElement();
095 String path = url.getPath();
096 if (path.startsWith("/")) {
097 path = path.substring(1);
098 }
099 paths.add(path);
100 }
101 return Collections.enumeration(paths);
102 }
103
104 /**
105 * Works like {@link Bundle#getEntry(String)} but also checks
106 * attached fragment bundles for the given entry.
107 *
108 * @param bundle
109 * @param name
110 * @return
111 */
112 public static URL getEntry(Bundle bundle, String name) {
113 if (name.equals("/")) {
114 return bundle.getEntry(name);
115 } else if (name.endsWith("/")) {
116 name = name.substring(0, name.length() - 1);
117 }
118 String path;
119 String pattern;
120 int pos = name.lastIndexOf("/");
121 if (pos == -1) {
122 path = "/";
123 pattern = name;
124 } else if (pos == 0) {
125 path = "/";
126 pattern = name.substring(1);
127 } else {
128 path = name.substring(0, pos);
129 pattern = name.substring(pos + 1);
130 }
131 Enumeration<URL> entries = bundle.findEntries(path, pattern, false);
132 if (entries != null && entries.hasMoreElements()) {
133 return entries.nextElement();
134 } else {
135 return null;
136 }
137 }
138
139 public static LinkedHashSet<Bundle> getWiredBundles(Bundle bundle) {
140 ServiceReference reference = bundle.getBundleContext().getServiceReference(PackageAdmin.class.getName());
141 PackageAdmin packageAdmin = (PackageAdmin) bundle.getBundleContext().getService(reference);
142 try {
143 return getWiredBundles(packageAdmin, bundle);
144 } finally {
145 bundle.getBundleContext().ungetService(reference);
146 }
147 }
148
149 public static LinkedHashSet<Bundle> getWiredBundles(PackageAdmin packageAdmin, Bundle bundle) {
150 BundleDescription description = new BundleDescription(bundle.getHeaders());
151 // handle static wire via Import-Package
152 List<BundleDescription.ImportPackage> imports = description.getExternalImports();
153 LinkedHashSet<Bundle> wiredBundles = new LinkedHashSet<Bundle>();
154 for (BundleDescription.ImportPackage packageImport : imports) {
155 ExportedPackage[] exports = packageAdmin.getExportedPackages(packageImport.getName());
156 Bundle wiredBundle = getWiredBundle(bundle, exports);
157 if (wiredBundle != null) {
158 wiredBundles.add(wiredBundle);
159 }
160 }
161 // handle dynamic wire via DynamicImport-Package
162 if (!description.getDynamicImportPackage().isEmpty()) {
163 for (Bundle b : bundle.getBundleContext().getBundles()) {
164 if (!wiredBundles.contains(b)) {
165 ExportedPackage[] exports = packageAdmin.getExportedPackages(b);
166 Bundle wiredBundle = getWiredBundle(bundle, exports);
167 if (wiredBundle != null) {
168 wiredBundles.add(wiredBundle);
169 }
170 }
171 }
172 }
173 return wiredBundles;
174 }
175
176 private static Bundle getWiredBundle(Bundle bundle, ExportedPackage[] exports) {
177 if (exports != null) {
178 for (ExportedPackage exportedPackage : exports) {
179 Bundle[] importingBundles = exportedPackage.getImportingBundles();
180 if (importingBundles != null) {
181 for (Bundle importingBundle : importingBundles) {
182 if (importingBundle == bundle) {
183 return exportedPackage.getExportingBundle();
184 }
185 }
186 }
187 }
188 }
189 return null;
190 }
191 }