org.apache.ace.deployment.itest/src/org/apache/ace/it/deployment/provider/filebased/FileBasedProvider.java - ace - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied.  See the License for the
  * specific language governing permissions and limitations
  * under the License.
  */
 package org.apache.ace.it.deployment.provider.filebased;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.URLConnection;
 import java.net.URLStreamHandler;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Dictionary;
 import java.util.Iterator;
 import java.util.List;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.jar.Attributes;
 import java.util.jar.JarInputStream;
 import java.util.jar.Manifest;

 import org.apache.ace.deployment.provider.ArtifactData;
 import org.apache.ace.deployment.provider.DeploymentProvider;
 import org.apache.ace.deployment.provider.OverloadedException;
 import org.apache.ace.deployment.provider.impl.ArtifactDataImpl;
 import org.osgi.framework.Constants;
 import org.osgi.framework.Version;
 import org.osgi.service.cm.ConfigurationException;
 import org.osgi.service.cm.ManagedService;
 import org.osgi.service.log.LogService;

 /**
  * This class reads data from the filesystem. It contains deployment data in the following format: <storage dir>/<target-name>/<bundle-version>/<jars>
  * example : storage-directory/ storage-directory/target-a storage-directory/target-a/1.0.0
  * storage-directory/target-a/1.0.0/bundle1.jar storage-directory/target-a/1.0.0/bundle2.jar storage-directory/target-a/1.1.0
  * storage-directory/target-a/1.1.0/bundle2.jar storage-directory/target-a/1.1.0/bundle3.jar The versions are in the
  * org.osgi.framework.Version format.
  */
 public class FileBasedProvider implements DeploymentProvider, ManagedService {
     /** Directory where all the target ID folders are located. */
     private static final String DIRECTORY_NAME = "BaseDirectoryName";
     /** Fallback directory for all targets that have no specific versions. Defaults to BaseDirectoryName if not specified. */
     private static final String DEFAULT_DIRECTORY_NAME = "DefaultDirectoryName";
     /** Configuration key for the number of concurrent users */
     private static final String MAXIMUM_NUMBER_OF_USERS = "MaximumNumberOfUsers";
     private static final int OSGI_R4_MANIFEST_VERSION = 2;
     private volatile File m_baseDirectory;
     private volatile File m_defaultDirectory;
     private volatile LogService m_log;
     private final Semaphore m_disk = new Semaphore(1, true);

     private final AtomicInteger m_usageCounter = new AtomicInteger();
     /** Maximum number of concurrent users. Value 0 is used for unlimited users. */
     private int m_maximumNumberOfUsers = 0;
     /** The default backoff time for each new user over the limit */
     private static final int BACKOFF_TIME_PER_USER = 5;

     /**
      * Get the bundle data from the bundles in the &lt;data dir&gt;/&lt;target&gt;/&lt;version&gt; directory It reads the manifest from all the
      * .jar files in that directory. If the manifest cannot be found, This method can only parse OSGi R4 bundles
      */
     public List<ArtifactData> getBundleData(String targetId, String version) throws OverloadedException, IllegalArgumentException {
         try {
             int concurrentUsers = m_usageCounter.incrementAndGet();
             if (m_maximumNumberOfUsers != 0  && m_maximumNumberOfUsers < concurrentUsers) {
                 throw new OverloadedException("Too many users, maximum allowed = " + m_maximumNumberOfUsers + ", current = " + concurrentUsers,  (concurrentUsers - m_maximumNumberOfUsers) * BACKOFF_TIME_PER_USER);
             }
             return internalGetBundleData(targetId, version);
         } finally {
             m_usageCounter.getAndDecrement();
         }

     }

     /**
      * Version folder and requested version do not always match (see implementation of getVersions, which uses Versions.parseVersion to allow different styles)
      * like 1 instead of 1.0.0 and alike.
      * So we need to do some crawling to map them.
      *
      * @param targetDirectory store directory
      * @param version          that has been requested.
      *
      * @return the matching folder.
      *
      * @throws IllegalArgumentException if no matching folder has been found. If this happens something is weirdly wrong.
      */
     private File findMatchingVersionDirectory(File targetDirectory, String version) {
         // first try the direct way:
         File directTry = new File(targetDirectory, version);
         if ((directTry != null) && directTry.isDirectory()) {
             return directTry;
         }
         // otherwise try to find it:
         Version requestedVersion;
         try {
             requestedVersion = Version.parseVersion(version);
         }
         catch (IllegalArgumentException iae) {
             throw new IllegalArgumentException("Requested version " + version + " has no matching folder in store: " + targetDirectory.getAbsolutePath());
         }

         File[] files = targetDirectory.listFiles();
         for (int i = 0; i < files.length; i++) {
             File possibleVersionDirectory = files[i];
             if (possibleVersionDirectory.isDirectory()) {
                 // ok, it is a directory. Now see if it is a version
                 try {
                     Version foundVersion = Version.parseVersion(possibleVersionDirectory.getName());
                     // no exception, but is could still be an empty version
                     if ((requestedVersion != null) && requestedVersion.equals(foundVersion)) {
                         return new File(targetDirectory, possibleVersionDirectory.getName());
                     }
                 }
                 catch (IllegalArgumentException iae) {
                     // dont' care at this point.
                 }
             }
         }
         throw new IllegalArgumentException("Requested version " + version + " has no matching folder in store: " + targetDirectory.getAbsolutePath());
     }

     public List<ArtifactData> getBundleData(String targetId, String versionFrom, String versionTo) throws OverloadedException, IllegalArgumentException {
         try {
             int concurrentUsers = m_usageCounter.incrementAndGet();
             if (m_maximumNumberOfUsers != 0  && m_maximumNumberOfUsers < concurrentUsers) {
                 throw new OverloadedException("Too many users, maximum allowed = " + m_maximumNumberOfUsers + ", current = " + concurrentUsers,  (concurrentUsers - m_maximumNumberOfUsers) * BACKOFF_TIME_PER_USER);
             }
             List<ArtifactData> dataVersionFrom = internalGetBundleData(targetId, versionFrom);
             List<ArtifactData> dataVersionTo = internalGetBundleData(targetId, versionTo);

             Iterator<ArtifactData> it = dataVersionTo.iterator();
             while (it.hasNext()) {
                 ArtifactDataImpl bundleDataVersionTo = (ArtifactDataImpl) it.next();
                 // see if there was previously a version of this bundle.
                 ArtifactData bundleDataVersionFrom = getBundleData(bundleDataVersionTo.getSymbolicName(), dataVersionFrom);
                 bundleDataVersionTo.setChanged(!bundleDataVersionTo.equals(bundleDataVersionFrom));
             }
             return dataVersionTo;
         } finally {
             m_usageCounter.getAndDecrement();
         }
     }

     /**
      * Check for the existence of bundledata in the collection for a bundle with the given symbolic name
      *
      * @param symbolicName
      */
     private ArtifactData getBundleData(String symbolicName, Collection<ArtifactData> data) {
         Iterator<ArtifactData> it = data.iterator();
         while (it.hasNext()) {
             ArtifactData bundle = it.next();
             if (bundle.getSymbolicName().equals(symbolicName)) {
                 return bundle;
             }
         }
         return null;
     }

     /**
      * Look in the baseDirectory for the specified target. If it exists, get the list of directories in there and check if they
      * conform to the <code>org.osgi.framework.Version</code> format. If it does, it will be in the list of versions that are
      * returned. If there are no valid versions, return an empty list. If the target cannot be found, an
      * IllegalArgumentException is thrown. The list will be sorted on version.
      */
     public List<String> getVersions(String targetId) throws OverloadedException, IllegalArgumentException {
         try {
             int concurrentUsers = m_usageCounter.incrementAndGet();
             if (m_maximumNumberOfUsers != 0  && m_maximumNumberOfUsers < concurrentUsers) {
                 throw new OverloadedException("Too many users, maximum allowed = " + m_maximumNumberOfUsers + ", current = " + concurrentUsers,  (concurrentUsers - m_maximumNumberOfUsers) * BACKOFF_TIME_PER_USER);
             }
             List<Version> versionList = new ArrayList<>();
             File targetDirectory = new File(m_baseDirectory.getAbsolutePath(), targetId);
             if (targetDirectory.isDirectory()) {
                 getVersions(targetId, versionList, targetDirectory);
             }
             else {
                 // try the default
                 getVersions(targetId, versionList, m_defaultDirectory);
             }

             // now sort the list of versions and convert all values to strings.
             Collections.sort(versionList);
             List<String> stringVersionList = new ArrayList<>();
             Iterator<Version> it = versionList.iterator();
             while (it.hasNext()) {
                 String version = (it.next()).toString();
                 stringVersionList.add(version);
             }
             return stringVersionList;
         } finally {
             m_usageCounter.getAndDecrement();
         }
     }

     private List<ArtifactData> internalGetBundleData(String targetId, String version) throws OverloadedException, IllegalArgumentException {
         List<String> versions = getVersions(targetId);
         if (!versions.contains(version)) {
             throw new IllegalArgumentException("Unknown version " + version + " requested");
         }
         File targetDirectory = new File(m_baseDirectory, targetId);
         File versionDirectory;
         if (targetDirectory.isDirectory()) {
             // target has its own folder
             versionDirectory = findMatchingVersionDirectory(targetDirectory, version);
         }
         else {
             versionDirectory = findMatchingVersionDirectory(m_defaultDirectory, version);
         }
         List<ArtifactData> bundleData = new ArrayList<>();

         JarInputStream jarInputStream = null;

         File[] jarFiles = versionDirectory.listFiles();
         for (int i = 0; i < jarFiles.length; i++) {
             Manifest bundleManifest = null;
             File jarFile = jarFiles[i];
             try {
                 jarInputStream = new JarInputStream(new FileInputStream(jarFile));
                 bundleManifest = jarInputStream.getManifest();
             }
             catch (IOException ioe) {
                 m_log.log(LogService.LOG_WARNING, "Error making inputstream", ioe);
                 continue;
             }
             finally {
                 if (jarInputStream != null) {
                     try {
                         jarInputStream.close();
                     }
                     catch (Exception ioe) {
                         m_log.log(LogService.LOG_ERROR, "Error closing the file input stream", ioe);
                     }
                 }
             }
             Attributes mainAttributes = bundleManifest.getMainAttributes();
             String manifestVersion = mainAttributes.getValue(Constants.BUNDLE_MANIFESTVERSION);
             String symbolicName = mainAttributes.getValue(Constants.BUNDLE_SYMBOLICNAME);
             String bundleVersion = mainAttributes.getValue(Constants.BUNDLE_VERSION);

             if ((manifestVersion != null) && (symbolicName != null) && (bundleVersion != null)) {
                 // ok, now at least we have the required attributes
                 // now check if they have the expected values
                 if (OSGI_R4_MANIFEST_VERSION != new Integer(manifestVersion).intValue()) {
                     m_log.log(LogService.LOG_WARNING, "Invalid bundle:" + jarFile.getAbsolutePath() + " has the wrong manifest version.");
                 }
                 else {
                     // it is the right manifest version
                     if (symbolicName.trim().equals("")) {
                         m_log.log(LogService.LOG_WARNING, "Invalid bundle:" + jarFile.getAbsolutePath() + " the symbolic name is empty.");
                     }
                     else {
                         // it also has the right symbolic name
                         try {
                             new Version(bundleVersion);
                             // Do a file.toURI().toURL() to preserve special path characters
                             // see http://www.javalobby.org/java/forums/t19698.html
                             URL bundleUrl = new URL(null, jarFile.toURI().toURL().toString(), new URLStreamHandler() {
                                 @Override
                                 protected URLConnection openConnection(final URL u) throws IOException {
                                     return new URLConnection(u) {
                                         @Override
                                         public void connect() throws IOException {
                                             // TODO Auto-generated method stub
                                         }
                                         @Override
                                         public InputStream getInputStream() throws IOException {
                                             final InputStream parent;
                                             try {
                                                 parent = new URL(u.toURI().toURL().toString()).openStream();
                                             }
                                             catch (URISyntaxException ex) {
                                                 throw new IOException(ex.getMessage());
                                             }
                                             return new InputStream() {
                                                 @Override
                                                 public int read() throws IOException {
                                                     return parent.read();
                                                 }

                                                 @Override
                                                 public int read(byte[] buffer) throws IOException {
                                                     return read(buffer, 0, buffer.length);
                                                 }

                                                 @Override
                                                 public int read(byte[] buffer, int off, int length) throws IOException {
                                                     m_disk.acquireUninterruptibly();
                                                     try {
                                                         return parent.read(buffer, off, length);
                                                     }
                                                     finally {
                                                         m_disk.release();
                                                     }
                                                 }

                                                 @Override
                                                 public void close() throws IOException {
                                                     parent.close();
                                                 }
                                             };
                                         }
                                     };
                                 }
                             });
                             bundleData.add(new ArtifactDataImpl(jarFile.getName(), symbolicName, jarFile.length(), bundleVersion, bundleUrl, true));
                         }
                         catch (IllegalArgumentException iae) {
                             m_log.log(LogService.LOG_WARNING, "Invalid bundle:" + jarFile.getAbsolutePath() + " has an illegal version", iae);
                         }
                         catch (MalformedURLException mue) {
                             m_log.log(LogService.LOG_WARNING, "Invalid bundle:" + jarFile.getAbsolutePath() + " unable to convert path to URL", mue);
                         }
                     }
                 }
             }
             else {
                 m_log.log(LogService.LOG_WARNING, "Invalid bundle:" + jarFile.getAbsolutePath() + " is missing required attributes");
             }
         }

         return bundleData;
     }

     /**
      *
      * @param targetId ID that requested versions
      * @param versionList where collected versions will be put into.
      * @param base folder to be crawled.
      */
     private void getVersions(String targetId, List<Version> versionList, File base) {
         // ok, it is a directory. Now treat all the subdirectories as seperate versions
         File[] files = base.listFiles();
         for (int i = 0; i < files.length; i++) {
             File possibleVersionDirectory = files[i];
             if (possibleVersionDirectory.isDirectory()) {
                 // ok, it is a directory. Now see if it is a version
                 try {
                     Version version = Version.parseVersion(possibleVersionDirectory.getName());
                     // no exception, but is could still be an empty version
                     if (!version.equals(Version.emptyVersion)) {
                         versionList.add(version);
                     }
                 }
                 catch (IllegalArgumentException iae) {
                     // do nothing. This version will be ignored.
                 }
             }
         }
         if (files.length == 0) {
             m_log.log(LogService.LOG_DEBUG, "No versions found for target: " + targetId);
         }
     }

     /**
      * Update the configuration for this bundle. It checks if the basedirectory exists and is a directory.
      */
     public void updated(Dictionary<String, ?> settings) throws ConfigurationException {
         if (settings != null) {
             String maximumNumberOfUsers = (String) settings.get(MAXIMUM_NUMBER_OF_USERS);
             if (maximumNumberOfUsers != null) {
                 m_maximumNumberOfUsers = Integer.parseInt(maximumNumberOfUsers);
             }

             String baseDirectoryName = getNotNull(settings, DIRECTORY_NAME, "The base directory cannot be null");
             File baseDirectory = new File(baseDirectoryName);
             if (!baseDirectory.exists() || !baseDirectory.isDirectory()) {
                 throw new ConfigurationException(DIRECTORY_NAME, "The directory called '" + baseDirectoryName + "' " + (baseDirectory.exists() ? "is no directory." : "doesn't exist."));
             }
             m_baseDirectory = baseDirectory;

             String defaultDirectoryName = (String) settings.get(DEFAULT_DIRECTORY_NAME);
             if (defaultDirectoryName != null) {
                 File defaultDirectory = new File(defaultDirectoryName);
                 if (defaultDirectory.exists() && defaultDirectory.isDirectory()) {
                     m_defaultDirectory = defaultDirectory;
                     return;
                 }
             }
             // fallback to using the base directory
             m_defaultDirectory = baseDirectory;
         }
     }

     /**
      * Convenience method for getting settings from a configuration dictionary.
      */
     private String getNotNull(Dictionary<String, ?> settings, String id, String errorMessage) throws ConfigurationException {
         String result = (String) settings.get(id);
         if (result == null) {
             throw new ConfigurationException(id, errorMessage);
         }
         return result;
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*/
	package org.apache.ace.it.deployment.provider.filebased;

	import java.io.File;
	import java.io.FileInputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.net.MalformedURLException;
	import java.net.URISyntaxException;
	import java.net.URL;
	import java.net.URLConnection;
	import java.net.URLStreamHandler;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.Dictionary;
	import java.util.Iterator;
	import java.util.List;
	import java.util.concurrent.Semaphore;
	import java.util.concurrent.atomic.AtomicInteger;
	import java.util.jar.Attributes;
	import java.util.jar.JarInputStream;
	import java.util.jar.Manifest;

	import org.apache.ace.deployment.provider.ArtifactData;
	import org.apache.ace.deployment.provider.DeploymentProvider;
	import org.apache.ace.deployment.provider.OverloadedException;
	import org.apache.ace.deployment.provider.impl.ArtifactDataImpl;
	import org.osgi.framework.Constants;
	import org.osgi.framework.Version;
	import org.osgi.service.cm.ConfigurationException;
	import org.osgi.service.cm.ManagedService;
	import org.osgi.service.log.LogService;

	/**
	* This class reads data from the filesystem. It contains deployment data in the following format: <storage dir>/<target-name>/<bundle-version>/<jars>
	* example : storage-directory/ storage-directory/target-a storage-directory/target-a/1.0.0
	* storage-directory/target-a/1.0.0/bundle1.jar storage-directory/target-a/1.0.0/bundle2.jar storage-directory/target-a/1.1.0
	* storage-directory/target-a/1.1.0/bundle2.jar storage-directory/target-a/1.1.0/bundle3.jar The versions are in the
	* org.osgi.framework.Version format.
	*/
	public class FileBasedProvider implements DeploymentProvider, ManagedService {
	/** Directory where all the target ID folders are located. */
	private static final String DIRECTORY_NAME = "BaseDirectoryName";
	/** Fallback directory for all targets that have no specific versions. Defaults to BaseDirectoryName if not specified. */
	private static final String DEFAULT_DIRECTORY_NAME = "DefaultDirectoryName";
	/** Configuration key for the number of concurrent users */
	private static final String MAXIMUM_NUMBER_OF_USERS = "MaximumNumberOfUsers";
	private static final int OSGI_R4_MANIFEST_VERSION = 2;
	private volatile File m_baseDirectory;
	private volatile File m_defaultDirectory;
	private volatile LogService m_log;
	private final Semaphore m_disk = new Semaphore(1, true);

	private final AtomicInteger m_usageCounter = new AtomicInteger();
	/** Maximum number of concurrent users. Value 0 is used for unlimited users. */
	private int m_maximumNumberOfUsers = 0;
	/** The default backoff time for each new user over the limit */
	private static final int BACKOFF_TIME_PER_USER = 5;

	/**
	* Get the bundle data from the bundles in the <data dir>/<target>/<version> directory It reads the manifest from all the
	* .jar files in that directory. If the manifest cannot be found, This method can only parse OSGi R4 bundles
	*/
	public List<ArtifactData> getBundleData(String targetId, String version) throws OverloadedException, IllegalArgumentException {
	try {
	int concurrentUsers = m_usageCounter.incrementAndGet();
	if (m_maximumNumberOfUsers != 0 && m_maximumNumberOfUsers < concurrentUsers) {
	throw new OverloadedException("Too many users, maximum allowed = " + m_maximumNumberOfUsers + ", current = " + concurrentUsers, (concurrentUsers - m_maximumNumberOfUsers) * BACKOFF_TIME_PER_USER);
	}
	return internalGetBundleData(targetId, version);
	} finally {
	m_usageCounter.getAndDecrement();
	}

	}

	/**
	* Version folder and requested version do not always match (see implementation of getVersions, which uses Versions.parseVersion to allow different styles)
	* like 1 instead of 1.0.0 and alike.
	* So we need to do some crawling to map them.
	*
	* @param targetDirectory store directory
	* @param version that has been requested.
	*
	* @return the matching folder.
	*
	* @throws IllegalArgumentException if no matching folder has been found. If this happens something is weirdly wrong.
	*/
	private File findMatchingVersionDirectory(File targetDirectory, String version) {
	// first try the direct way:
	File directTry = new File(targetDirectory, version);
	if ((directTry != null) && directTry.isDirectory()) {
	return directTry;
	}
	// otherwise try to find it:
	Version requestedVersion;
	try {
	requestedVersion = Version.parseVersion(version);
	}
	catch (IllegalArgumentException iae) {
	throw new IllegalArgumentException("Requested version " + version + " has no matching folder in store: " + targetDirectory.getAbsolutePath());
	}

	File[] files = targetDirectory.listFiles();
	for (int i = 0; i < files.length; i++) {
	File possibleVersionDirectory = files[i];
	if (possibleVersionDirectory.isDirectory()) {
	// ok, it is a directory. Now see if it is a version
	try {
	Version foundVersion = Version.parseVersion(possibleVersionDirectory.getName());
	// no exception, but is could still be an empty version
	if ((requestedVersion != null) && requestedVersion.equals(foundVersion)) {
	return new File(targetDirectory, possibleVersionDirectory.getName());
	}
	}
	catch (IllegalArgumentException iae) {
	// dont' care at this point.
	}
	}
	}
	throw new IllegalArgumentException("Requested version " + version + " has no matching folder in store: " + targetDirectory.getAbsolutePath());
	}

	public List<ArtifactData> getBundleData(String targetId, String versionFrom, String versionTo) throws OverloadedException, IllegalArgumentException {
	try {
	int concurrentUsers = m_usageCounter.incrementAndGet();
	if (m_maximumNumberOfUsers != 0 && m_maximumNumberOfUsers < concurrentUsers) {
	throw new OverloadedException("Too many users, maximum allowed = " + m_maximumNumberOfUsers + ", current = " + concurrentUsers, (concurrentUsers - m_maximumNumberOfUsers) * BACKOFF_TIME_PER_USER);
	}
	List<ArtifactData> dataVersionFrom = internalGetBundleData(targetId, versionFrom);
	List<ArtifactData> dataVersionTo = internalGetBundleData(targetId, versionTo);

	Iterator<ArtifactData> it = dataVersionTo.iterator();
	while (it.hasNext()) {
	ArtifactDataImpl bundleDataVersionTo = (ArtifactDataImpl) it.next();
	// see if there was previously a version of this bundle.
	ArtifactData bundleDataVersionFrom = getBundleData(bundleDataVersionTo.getSymbolicName(), dataVersionFrom);
	bundleDataVersionTo.setChanged(!bundleDataVersionTo.equals(bundleDataVersionFrom));
	}
	return dataVersionTo;
	} finally {
	m_usageCounter.getAndDecrement();
	}
	}

	/**
	* Check for the existence of bundledata in the collection for a bundle with the given symbolic name
	*
	* @param symbolicName
	*/
	private ArtifactData getBundleData(String symbolicName, Collection<ArtifactData> data) {
	Iterator<ArtifactData> it = data.iterator();
	while (it.hasNext()) {
	ArtifactData bundle = it.next();
	if (bundle.getSymbolicName().equals(symbolicName)) {
	return bundle;
	}
	}
	return null;
	}

	/**
	* Look in the baseDirectory for the specified target. If it exists, get the list of directories in there and check if they
	* conform to the <code>org.osgi.framework.Version</code> format. If it does, it will be in the list of versions that are
	* returned. If there are no valid versions, return an empty list. If the target cannot be found, an
	* IllegalArgumentException is thrown. The list will be sorted on version.
	*/
	public List<String> getVersions(String targetId) throws OverloadedException, IllegalArgumentException {
	try {
	int concurrentUsers = m_usageCounter.incrementAndGet();
	if (m_maximumNumberOfUsers != 0 && m_maximumNumberOfUsers < concurrentUsers) {
	throw new OverloadedException("Too many users, maximum allowed = " + m_maximumNumberOfUsers + ", current = " + concurrentUsers, (concurrentUsers - m_maximumNumberOfUsers) * BACKOFF_TIME_PER_USER);
	}
	List<Version> versionList = new ArrayList<>();
	File targetDirectory = new File(m_baseDirectory.getAbsolutePath(), targetId);
	if (targetDirectory.isDirectory()) {
	getVersions(targetId, versionList, targetDirectory);
	}
	else {
	// try the default
	getVersions(targetId, versionList, m_defaultDirectory);
	}

	// now sort the list of versions and convert all values to strings.
	Collections.sort(versionList);
	List<String> stringVersionList = new ArrayList<>();
	Iterator<Version> it = versionList.iterator();
	while (it.hasNext()) {
	String version = (it.next()).toString();
	stringVersionList.add(version);
	}
	return stringVersionList;
	} finally {
	m_usageCounter.getAndDecrement();
	}
	}

	private List<ArtifactData> internalGetBundleData(String targetId, String version) throws OverloadedException, IllegalArgumentException {
	List<String> versions = getVersions(targetId);
	if (!versions.contains(version)) {
	throw new IllegalArgumentException("Unknown version " + version + " requested");
	}
	File targetDirectory = new File(m_baseDirectory, targetId);
	File versionDirectory;
	if (targetDirectory.isDirectory()) {
	// target has its own folder
	versionDirectory = findMatchingVersionDirectory(targetDirectory, version);
	}
	else {
	versionDirectory = findMatchingVersionDirectory(m_defaultDirectory, version);
	}
	List<ArtifactData> bundleData = new ArrayList<>();

	JarInputStream jarInputStream = null;

	File[] jarFiles = versionDirectory.listFiles();
	for (int i = 0; i < jarFiles.length; i++) {
	Manifest bundleManifest = null;
	File jarFile = jarFiles[i];
	try {
	jarInputStream = new JarInputStream(new FileInputStream(jarFile));
	bundleManifest = jarInputStream.getManifest();
	}
	catch (IOException ioe) {
	m_log.log(LogService.LOG_WARNING, "Error making inputstream", ioe);
	continue;
	}
	finally {
	if (jarInputStream != null) {
	try {
	jarInputStream.close();
	}
	catch (Exception ioe) {
	m_log.log(LogService.LOG_ERROR, "Error closing the file input stream", ioe);
	}
	}
	}
	Attributes mainAttributes = bundleManifest.getMainAttributes();
	String manifestVersion = mainAttributes.getValue(Constants.BUNDLE_MANIFESTVERSION);
	String symbolicName = mainAttributes.getValue(Constants.BUNDLE_SYMBOLICNAME);
	String bundleVersion = mainAttributes.getValue(Constants.BUNDLE_VERSION);

	if ((manifestVersion != null) && (symbolicName != null) && (bundleVersion != null)) {
	// ok, now at least we have the required attributes
	// now check if they have the expected values
	if (OSGI_R4_MANIFEST_VERSION != new Integer(manifestVersion).intValue()) {
	m_log.log(LogService.LOG_WARNING, "Invalid bundle:" + jarFile.getAbsolutePath() + " has the wrong manifest version.");
	}
	else {
	// it is the right manifest version
	if (symbolicName.trim().equals("")) {
	m_log.log(LogService.LOG_WARNING, "Invalid bundle:" + jarFile.getAbsolutePath() + " the symbolic name is empty.");
	}
	else {
	// it also has the right symbolic name
	try {
	new Version(bundleVersion);
	// Do a file.toURI().toURL() to preserve special path characters
	// see http://www.javalobby.org/java/forums/t19698.html
	URL bundleUrl = new URL(null, jarFile.toURI().toURL().toString(), new URLStreamHandler() {
	@Override
	protected URLConnection openConnection(final URL u) throws IOException {
	return new URLConnection(u) {
	@Override
	public void connect() throws IOException {
	// TODO Auto-generated method stub
	}
	@Override
	public InputStream getInputStream() throws IOException {
	final InputStream parent;
	try {
	parent = new URL(u.toURI().toURL().toString()).openStream();
	}
	catch (URISyntaxException ex) {
	throw new IOException(ex.getMessage());
	}
	return new InputStream() {
	@Override
	public int read() throws IOException {
	return parent.read();
	}

	@Override
	public int read(byte[] buffer) throws IOException {
	return read(buffer, 0, buffer.length);
	}

	@Override
	public int read(byte[] buffer, int off, int length) throws IOException {
	m_disk.acquireUninterruptibly();
	try {
	return parent.read(buffer, off, length);
	}
	finally {
	m_disk.release();
	}
	}

	@Override
	public void close() throws IOException {
	parent.close();
	}
	};
	}
	};
	}
	});
	bundleData.add(new ArtifactDataImpl(jarFile.getName(), symbolicName, jarFile.length(), bundleVersion, bundleUrl, true));
	}
	catch (IllegalArgumentException iae) {
	m_log.log(LogService.LOG_WARNING, "Invalid bundle:" + jarFile.getAbsolutePath() + " has an illegal version", iae);
	}
	catch (MalformedURLException mue) {
	m_log.log(LogService.LOG_WARNING, "Invalid bundle:" + jarFile.getAbsolutePath() + " unable to convert path to URL", mue);
	}
	}
	}
	}
	else {
	m_log.log(LogService.LOG_WARNING, "Invalid bundle:" + jarFile.getAbsolutePath() + " is missing required attributes");
	}
	}

	return bundleData;
	}

	/**
	*
	* @param targetId ID that requested versions
	* @param versionList where collected versions will be put into.
	* @param base folder to be crawled.
	*/
	private void getVersions(String targetId, List<Version> versionList, File base) {
	// ok, it is a directory. Now treat all the subdirectories as seperate versions
	File[] files = base.listFiles();
	for (int i = 0; i < files.length; i++) {
	File possibleVersionDirectory = files[i];
	if (possibleVersionDirectory.isDirectory()) {
	// ok, it is a directory. Now see if it is a version
	try {
	Version version = Version.parseVersion(possibleVersionDirectory.getName());
	// no exception, but is could still be an empty version
	if (!version.equals(Version.emptyVersion)) {
	versionList.add(version);
	}
	}
	catch (IllegalArgumentException iae) {
	// do nothing. This version will be ignored.
	}
	}
	}
	if (files.length == 0) {
	m_log.log(LogService.LOG_DEBUG, "No versions found for target: " + targetId);
	}
	}

	/**
	* Update the configuration for this bundle. It checks if the basedirectory exists and is a directory.
	*/
	public void updated(Dictionary<String, ?> settings) throws ConfigurationException {
	if (settings != null) {
	String maximumNumberOfUsers = (String) settings.get(MAXIMUM_NUMBER_OF_USERS);
	if (maximumNumberOfUsers != null) {
	m_maximumNumberOfUsers = Integer.parseInt(maximumNumberOfUsers);
	}

	String baseDirectoryName = getNotNull(settings, DIRECTORY_NAME, "The base directory cannot be null");
	File baseDirectory = new File(baseDirectoryName);
	if (!baseDirectory.exists() \|\| !baseDirectory.isDirectory()) {
	throw new ConfigurationException(DIRECTORY_NAME, "The directory called '" + baseDirectoryName + "' " + (baseDirectory.exists() ? "is no directory." : "doesn't exist."));
	}
	m_baseDirectory = baseDirectory;

	String defaultDirectoryName = (String) settings.get(DEFAULT_DIRECTORY_NAME);
	if (defaultDirectoryName != null) {
	File defaultDirectory = new File(defaultDirectoryName);
	if (defaultDirectory.exists() && defaultDirectory.isDirectory()) {
	m_defaultDirectory = defaultDirectory;
	return;
	}
	}
	// fallback to using the base directory
	m_defaultDirectory = baseDirectory;
	}
	}

	/**
	* Convenience method for getting settings from a configuration dictionary.
	*/
	private String getNotNull(Dictionary<String, ?> settings, String id, String errorMessage) throws ConfigurationException {
	String result = (String) settings.get(id);
	if (result == null) {
	throw new ConfigurationException(id, errorMessage);
	}
	return result;
	}
	}