Java tutorial
/* * This software copyright by various authors including the RPTools.net * development team, and licensed under the LGPL Version 3 or, at your option, * any later version. * * Portions of this software were originally covered under the Apache Software * License, Version 1.1 or Version 2.0. * * See the file LICENSE elsewhere in this distribution for license details. */ package net.rptools.maptool.model; import java.io.BufferedInputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.FilenameFilter; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.URL; import java.util.HashMap; import java.util.HashSet; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.Properties; import java.util.Set; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import net.rptools.lib.FileUtil; import net.rptools.lib.MD5Key; import net.rptools.maptool.client.AppUtil; import net.rptools.maptool.client.MapTool; import org.apache.commons.io.FileUtils; import org.apache.log4j.Logger; /** * This class handles the caching, loading, and downloading of assets. All assets are loaded through this class. * * @author RPTools Team * */ public class AssetManager { private static final Logger log = Logger.getLogger(AssetManager.class); /** Assets are associated with the MD5 sum of their raw data */ private static Map<MD5Key, Asset> assetMap = new ConcurrentHashMap<MD5Key, Asset>(); /** Location of the cache on the filesystem */ private static File cacheDir; /** True if a persistent cache should be used */ private static boolean usePersistentCache; /** * A list of listeners which should be notified when the asset associated with a given MD5 sum has finished * downloading. */ private static Map<MD5Key, List<AssetAvailableListener>> assetListenerListMap = new ConcurrentHashMap<MD5Key, List<AssetAvailableListener>>(); /** Property string associated with asset name */ public static final String NAME = "name"; /** Used to load assets from storage */ private static AssetLoader assetLoader = new AssetLoader(); private static ExecutorService assetLoaderThreadPool = Executors.newFixedThreadPool(1); static { cacheDir = AppUtil.getAppHome("assetcache"); if (cacheDir != null) { usePersistentCache = true; } } /** * Remove all existing repositories and load all the repositories from the currently loaded campaign. */ public static void updateRepositoryList() { assetLoader.removeAllRepositories(); for (String repo : MapTool.getCampaign().getRemoteRepositoryList()) { assetLoader.addRepository(repo); } } /** * Determine if the asset is currently being requested. While an asset is being loaded it will be marked as * requested and this function will return true. Once the asset is done loading this function will return false and * the asset will be available from the cache. * * @param key * MD5Key of asset being requested * @return True if asset is currently being requested, false otherwise */ public static boolean isAssetRequested(MD5Key key) { return assetLoader.isIdRequested(key); } /** * Register a listener with the asset manager. The listener will be notified when the asset is done loading. * * @param key * MD5Key of the asset * @param listener * Listener to notify when the asset is done loading */ public static void addAssetListener(MD5Key key, AssetAvailableListener... listeners) { if (listeners == null || listeners.length == 0) { return; } List<AssetAvailableListener> listenerList = assetListenerListMap.get(key); if (listenerList == null) { listenerList = new LinkedList<AssetAvailableListener>(); assetListenerListMap.put(key, listenerList); } for (AssetAvailableListener listener : listeners) { if (!listenerList.contains(listener)) { listenerList.add(listener); } } } public static void removeAssetListener(MD5Key key, AssetAvailableListener... listeners) { if (listeners == null || listeners.length == 0) { return; } List<AssetAvailableListener> listenerList = assetListenerListMap.get(key); if (listenerList == null) { // Nothing to do return; } for (AssetAvailableListener listener : listeners) { listenerList.remove(listener); } } /** * Determine if the asset manager has the asset. This does not tell you if the asset is done downloading. * * @param asset * Asset to look for * @return True if the asset exists, false otherwise */ public static boolean hasAsset(Asset asset) { return hasAsset(asset.getId()); } /** * Determine if the asset manager has the asset. This does not tell you if the asset is done downloading. * * @param key * @return */ public static boolean hasAsset(MD5Key key) { return assetMap.containsKey(key) || assetIsInPersistentCache(key) || assetHasLocalReference(key); } /** * Determines if the asset data is in memory. * * @param key * MD5 sum associated with asset * @return True if hte asset is loaded, false otherwise */ public static boolean hasAssetInMemory(MD5Key key) { return assetMap.containsKey(key); } /** * Add the asset to the asset cache. Listeners for this asset are notified. * * @param asset * Asset to add to cache */ public static void putAsset(Asset asset) { if (asset == null) { return; } assetMap.put(asset.getId(), asset); // Invalid images are represented by empty assets. // Don't persist those if (asset.getImage().length > 0) { putInPersistentCache(asset); } // Clear the waiting status assetLoader.completeRequest(asset.getId()); // Listeners List<AssetAvailableListener> listenerList = assetListenerListMap.get(asset.getId()); if (listenerList != null) { for (AssetAvailableListener listener : listenerList) { listener.assetAvailable(asset.getId()); } assetListenerListMap.remove(asset.getId()); } } /** * Similar to getAsset(), but does not block. It will always use the listeners to pass the data */ public static void getAssetAsynchronously(final MD5Key id, final AssetAvailableListener... listeners) { assetLoaderThreadPool.submit(new Runnable() { public void run() { Asset asset = getAsset(id); // Simplest case, we already have it if (asset != null) { for (AssetAvailableListener listener : listeners) { listener.assetAvailable(id); } return; } // Let's get it from the server // As a last resort we request the asset from the server if (asset == null && !isAssetRequested(id)) { requestAssetFromServer(id, listeners); } } }); } /** * Get the asset from the cache. If the asset is not currently available, will return null. Does not request the * asset from the server * * @param id * MD5 of the asset requested * @return Asset object for the MD5 sum */ public static Asset getAsset(MD5Key id) { if (id == null) { return null; } Asset asset = assetMap.get(id); if (asset == null && usePersistentCache && assetIsInPersistentCache(id)) { // Guaranteed that asset is in the cache. asset = getFromPersistentCache(id); } if (asset == null && assetHasLocalReference(id)) { File imageFile = getLocalReference(id); if (imageFile != null) { try { String name = FileUtil.getNameWithoutExtension(imageFile); byte[] data = FileUtils.readFileToByteArray(imageFile); asset = new Asset(name, data); // Just to be sure the image didn't change if (!asset.getId().equals(id)) { throw new IOException("Image reference did not match the requested image"); } // Put it in the persistent cache so we'll find it faster next time putInPersistentCache(asset); } catch (IOException ioe) { // Log, but continue as if we didn't have a link ioe.printStackTrace(); } } } return asset; } /** * Remove the asset from the asset cache. * * @param id * MD5 of the asset to remove */ public static void removeAsset(MD5Key id) { assetMap.remove(id); } /** * Enable the use of the persistent asset cache. * * @param enable * True to enable the cache, false to disable */ public static void setUsePersistentCache(boolean enable) { if (enable && cacheDir == null) { throw new IllegalArgumentException("Could not enable persistent cache: no such directory"); } usePersistentCache = enable; } /** * Request that the asset be loaded from the server * * @param id * MD5 of the asset to load from the server */ private static void requestAssetFromServer(MD5Key id, AssetAvailableListener... listeners) { if (id != null) { addAssetListener(id, listeners); assetLoader.requestAsset(id); } } /** * Retrieve the asset from the persistent cache. If the asset is not in the cache, or loading from the cache failed * then this function returns null. * * @param id * MD5 of the requested asset * @return Asset from the cache */ private static Asset getFromPersistentCache(MD5Key id) { if (id == null || id.toString().length() == 0) { return null; } if (!assetIsInPersistentCache(id)) { return null; } File assetFile = getAssetCacheFile(id); try { byte[] data = FileUtils.readFileToByteArray(assetFile); Properties props = getAssetInfo(id); Asset asset = new Asset(props.getProperty(NAME), data); if (!asset.getId().equals(id)) { log.error("MD5 for asset " + asset.getName() + " corrupted"); } assetMap.put(id, asset); return asset; } catch (IOException ioe) { log.error("Could not load asset from persistent cache", ioe); return null; } } /** * Create an asset from a file. * * @param file * File to use for asset * @return Asset associated with the file * @throws IOException */ public static Asset createAsset(File file) throws IOException { return new Asset(FileUtil.getNameWithoutExtension(file), FileUtils.readFileToByteArray(file)); } /** * Create an asset from a file. * * @param file * File to use for asset * @return Asset associated with the file * @throws IOException */ public static Asset createAsset(URL url) throws IOException { // Create a temporary file from the downloaded URL File newFile = File.createTempFile("remote", null, null); try { FileUtils.copyURLToFile(url, newFile); if (!newFile.exists() || newFile.length() < 20) return null; Asset temp = new Asset(FileUtil.getNameWithoutExtension(url), FileUtils.readFileToByteArray(newFile)); return temp; } finally { newFile.delete(); } } /** * Return a set of properties associated with the asset. * * @param id * MD5 of the asset * @return Properties object containing asset properties. */ public static Properties getAssetInfo(MD5Key id) { File infoFile = getAssetInfoFile(id); try { Properties props = new Properties(); InputStream is = new FileInputStream(infoFile); props.load(is); is.close(); return props; } catch (Exception e) { return new Properties(); } } /** * Serialize the asset into the persistent cache. * * @param asset * Asset to serialize */ private static void putInPersistentCache(final Asset asset) { if (!usePersistentCache) { return; } if (!assetIsInPersistentCache(asset)) { final File assetFile = getAssetCacheFile(asset); new Thread() { @Override public void run() { try { assetFile.getParentFile().mkdirs(); // Image OutputStream out = new FileOutputStream(assetFile); out.write(asset.getImage()); out.close(); } catch (IOException ioe) { log.error("Could not persist asset while writing image data", ioe); return; } } }.start(); } if (!assetInfoIsInPersistentCache(asset)) { File infoFile = getAssetInfoFile(asset); try { // Info OutputStream out = new FileOutputStream(infoFile); Properties props = new Properties(); props.put(NAME, asset.getName() != null ? asset.getName() : ""); props.store(out, "Asset Info"); out.close(); } catch (IOException ioe) { log.error("Could not persist asset while writing image properties", ioe); return; } } } /** * Return the file associated with the asset, if any. * * @param id * MD5 of the asset * @return The file associated with the asset, null if none. */ private static File getLocalReference(MD5Key id) { File lnkFile = getAssetLinkFile(id); if (!lnkFile.exists()) { return null; } try { List<String> refList = FileUtil.getLines(lnkFile); for (String ref : refList) { File refFile = new File(ref); if (refFile.exists()) { return refFile; } } } catch (IOException ioe) { // Just so we know, but fall through to return null ioe.printStackTrace(); } // Guess we don't have one return null; } /** * Store an absolute path to where this asset exists. Perhaps this should be saved in a single data structure that * is read/written when it's modified? This would allow the fileFilterText field from the AssetPanel the option of * searching through all directories and not just the current one. FJE * * @param image */ public static void rememberLocalImageReference(File image) throws IOException { MD5Key id = new MD5Key(new BufferedInputStream(new FileInputStream(image))); File lnkFile = getAssetLinkFile(id); // See if we know about this one already if (lnkFile.exists()) { List<String> referenceList = FileUtil.getLines(lnkFile); for (String ref : referenceList) { if (ref.equals(id.toString())) { // We already know about this one return; } } } // Keep track of this reference FileOutputStream out = new FileOutputStream(lnkFile, true); // For appending out.write((image.getAbsolutePath() + "\n").getBytes()); out.close(); } /** * Determine if the asset has a local reference * * @param id * MD5 sum of the asset * @return True if there is a local reference, false otherwise */ private static boolean assetHasLocalReference(MD5Key id) { return getLocalReference(id) != null; } /** * Determine if the asset is in the persistent cache. * * @param asset * Asset to search for * @return True if asset is in the persistent cache, false otherwise */ private static boolean assetIsInPersistentCache(Asset asset) { return assetIsInPersistentCache(asset.getId()); } /** * The assets information is in the persistent cache. * * @param asset * Asset to search for * @return True if the assets information exists in the persistent cache */ private static boolean assetInfoIsInPersistentCache(Asset asset) { return getAssetInfoFile(asset.getId()).exists(); } /** * Determine if the asset is in the persistent cache. * * @param id * MD5 sum of the asset * @return True if asset is in the persistent cache, false otherwise * @see assetIsInPersistentCache(Asset asset) */ private static boolean assetIsInPersistentCache(MD5Key id) { return getAssetCacheFile(id).exists() && getAssetCacheFile(id).length() > 0; } /** * Return the assets cache file, if any * * @param asset * Asset to search for * @return The assets cache file, or null if it doesn't have one */ public static File getAssetCacheFile(Asset asset) { return getAssetCacheFile(asset.getId()); } /** * Return the assets cache file, if any * * @param is * MD5 sum of the asset * @return The assets cache file, or null if it doesn't have one * @see getAssetCacheFile(Asset asset) */ public static File getAssetCacheFile(MD5Key id) { return new File(cacheDir.getAbsolutePath() + File.separator + id); } /** * Return the asset info file, if any * * @param asset * Asset to search for * @return The assets info file, or null if it doesn't have one */ private static File getAssetInfoFile(Asset asset) { return getAssetInfoFile(asset.getId()); } /** * Return the asset info file, if any * * @param id * MD5 sum of the asset * @return File - The assets info file, or null if it doesn't have one * @see getAssetInfoFile(Asset asset) */ private static File getAssetInfoFile(MD5Key id) { return new File(cacheDir.getAbsolutePath() + File.separator + id + ".info"); } /** * Return the asset link file, if any * * @param id * MD5 sum of the asset * @return File The asset link file */ private static File getAssetLinkFile(MD5Key id) { return new File(cacheDir.getAbsolutePath() + File.separator + id + ".lnk"); } /** * Recursively search from the rootDir, filtering files based on fileFilter, and store a reference to every file * seen. * * @param rootDir * Starting directory to recurse from * @param fileFilter * Only add references to image files that are allowed by the filter */ public static void searchForImageReferences(File rootDir, FilenameFilter fileFilter) { for (File file : rootDir.listFiles()) { if (file.isDirectory()) { searchForImageReferences(file, fileFilter); continue; } try { if (fileFilter.accept(rootDir, file.getName())) { if (MapTool.getFrame() != null) { MapTool.getFrame().setStatusMessage("Caching image reference: " + file.getName()); } rememberLocalImageReference(file); } } catch (IOException ioe) { ioe.printStackTrace(); } } // Done if (MapTool.getFrame() != null) { MapTool.getFrame().setStatusMessage(""); } } /** * <p> * This method accepts the name of a repository (as it appears in the CampaignProperties) and updates it by adding * the additional mappings that are in <code>add</code>. * </p> * <p> * This method first retrieves the mapping from the AssetLoader. It then adds in the new assets. Last, it has to * create the new index file. The index file should be stored in the local repository cache. Note that this function * <b>does not</b> update the original (network storage) repository location. * </p> * <p> * If the calling function does not update the network storage for <b>index.gz</b>, a restart of MapTool will lose * the information when the index is downloaded again. * </p> * * @param repo * name of the repository to update * @param add * entries to add to the repository * @return the contents of the new repository in uploadable format */ public static byte[] updateRepositoryMap(String repo, Map<String, String> add) { Map<String, String> repoMap = assetLoader.getRepositoryMap(repo); repoMap.putAll(add); byte[] index = assetLoader.createIndexFile(repo); try { assetLoader.storeIndexFile(repo, index); } catch (IOException e) { log.error("Couldn't save updated index to local repository cache", e); e.printStackTrace(); } return index; } /** * <p> * Constructs a set of all assets in the given list of repositories, then builds a map of <code>MD5Key</code> and * <code>Asset</code> for all assets that do not appear in that set. * </p> * <p> * This provides the calling function with a list of all assets currently in use by the campaign that do not appear * in one of the listed repositories. It's entirely possible that the asset is in a different repository or in none * at all. * </p> * * @param repos * list of repositories to exclude * @return Map of all known assets that are NOT in the specified repositories */ public static Map<MD5Key, Asset> findAllAssetsNotInRepositories(List<String> repos) { // For performance reasons, we calculate the size of the Set in advance... int size = 0; for (String repo : repos) { size += assetLoader.getRepositoryMap(repo).size(); } // Now create the aggregate of all repositories. Set<String> aggregate = new HashSet<String>(size); for (String repo : repos) { aggregate.addAll(assetLoader.getRepositoryMap(repo).keySet()); } /* * The 'aggregate' now holds the sum total of all asset keys that are in repositories. Now we go through the * 'assetMap' and copy over <K,V> pairs that are NOT in 'aggregate' to our 'missing' Map. * * Unfortunately, the repository is a Map<String, String> while the return value is going to be a Map<MD5Key, * Asset>, which means each individual entry needs to be checked and references copied. If both were the same * data type, converting both to Set<String> would allow for an addAll() and removeAll() and be done with it! */ Map<MD5Key, Asset> missing = new HashMap<MD5Key, Asset>(Math.min(assetMap.size(), aggregate.size())); for (MD5Key key : assetMap.keySet()) { if (aggregate.contains(key) == false) // Not in any repository so add it. missing.put(key, assetMap.get(key)); } return missing; } }