Java tutorial
/* * Licensed to the Sakai Foundation (SF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The SF 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 uk.co.tfd.sm.memory.ehcache; import java.io.ByteArrayInputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.lang.management.ManagementFactory; import java.lang.ref.WeakReference; import java.util.HashMap; import java.util.Map; import javax.management.MBeanServer; import net.sf.ehcache.CacheManager; import net.sf.ehcache.management.ManagementService; import org.apache.commons.io.IOUtils; import org.apache.felix.scr.annotations.Activate; import org.apache.felix.scr.annotations.Component; import org.apache.felix.scr.annotations.Deactivate; import org.apache.felix.scr.annotations.Property; import org.apache.felix.scr.annotations.Service; import org.sakaiproject.nakamura.api.memory.Cache; import org.sakaiproject.nakamura.api.memory.CacheManagerService; import org.sakaiproject.nakamura.api.memory.CacheScope; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * The <code>CacheManagerServiceImpl</code> */ @Component(immediate = true, metatype = true) @Service(value = CacheManagerService.class) public class CacheManagerServiceImpl implements CacheManagerService { public static final String DEFAULT_CACHE_CONFIG = "sling/ehcacheConfig.xml"; @Property(value = DEFAULT_CACHE_CONFIG) public static final String CACHE_CONFIG = "cache-config"; @Property(value = "The Sakai Foundation") static final String SERVICE_VENDOR = "service.vendor"; @Property(value = "Cache Manager Service Implementation") static final String SERVICE_DESCRIPTION = "service.description"; @Property() public static final String BIND_ADDRESS = "bind-address"; @Property(value = "sling/ehcache/data") public static final String CACHE_STORE = "cache-store"; private static final String CONFIG_PATH = "uk/co/tfd/sm/memory/ehcache/ehcacheConfig.xml"; private static final Logger LOGGER = LoggerFactory.getLogger(CacheManagerServiceImpl.class); private CacheManager cacheManager; private Map<String, Cache<?>> caches = new HashMap<String, Cache<?>>(); private ThreadLocalCacheMap requestCacheMapHolder = new ThreadLocalCacheMap(); private ThreadLocalCacheMap threadCacheMapHolder = new ThreadLocalCacheMap(); public CacheManagerServiceImpl() throws IOException { } @Activate public void activate(Map<String, Object> properties) throws FileNotFoundException, IOException { String config = toString(properties.get(CACHE_CONFIG), DEFAULT_CACHE_CONFIG); File configFile = new File(config); if (configFile.exists()) { LOGGER.info("Configuring Cache from {} ", configFile.getAbsolutePath()); InputStream in = null; try { in = processConfig(new FileInputStream(configFile), properties); cacheManager = new CacheManager(in); } finally { if (in != null) { in.close(); } } } else { LOGGER.info("Configuring Cache from Classpath Default {} ", CONFIG_PATH); InputStream in = processConfig(this.getClass().getClassLoader().getResourceAsStream(CONFIG_PATH), properties); if (in == null) { throw new IOException("Unable to open config at classpath location " + CONFIG_PATH); } cacheManager = new CacheManager(in); in.close(); } final WeakReference<CacheManagerServiceImpl> ref = new WeakReference<CacheManagerServiceImpl>(this); /* * Add in a shutdown hook, for safety */ Runtime.getRuntime().addShutdownHook(new Thread() { /* * (non-Javadoc) * * @see java.lang.Thread#run() */ @Override public void run() { try { CacheManagerServiceImpl cm = ref.get(); if (cm != null) { cm.deactivate(); } } catch (Throwable t) { LOGGER.debug(t.getMessage(), t); } } }); // register the cache manager with JMX MBeanServer mBeanServer = ManagementFactory.getPlatformMBeanServer(); ManagementService.registerMBeans(cacheManager, mBeanServer, true, true, true, true); } private String toString(Object object, String defaultValue) { if (object == null) { return defaultValue; } return String.valueOf(object); } private InputStream processConfig(InputStream in, Map<String, Object> properties) throws IOException { if (in == null) { return null; } StringBuilder config = new StringBuilder(IOUtils.toString(in, "UTF-8")); in.close(); int pos = 0; for (;;) { int start = config.indexOf("${", pos); if (start < 0) { break; } int end = config.indexOf("}", start); if (end < 0) { throw new IllegalArgumentException("Config file malformed, unterminated variable " + config.substring(start, Math.min(start + 10, config.length()))); } String key = config.substring(start + 2, end); if (properties.containsKey(key)) { String replacement = (String) properties.get(key); config.replace(start, end + 1, replacement); pos = start + replacement.length(); } else { throw new IllegalArgumentException("Missing replacement property " + key); } } return new ByteArrayInputStream(config.toString().getBytes("UTF-8")); } /** * perform a shutdown */ @Deactivate public void deactivate() { if (cacheManager != null) { cacheManager.shutdown(); cacheManager = null; } } /** * {@inheritDoc} * * @see org.sakaiproject.nakamura.api.memory.CacheManagerService#getCache(java.lang.String) */ public <V> Cache<V> getCache(String name, CacheScope scope) { switch (scope) { case INSTANCE: return getInstanceCache(name); case CLUSTERINVALIDATED: return getInstanceCache(name); case CLUSTERREPLICATED: return getInstanceCache(name); case REQUEST: return getRequestCache(name); case THREAD: return getThreadCache(name); default: return getInstanceCache(name); } } /** * Generate a cache bound to the thread. * * @param name * @return */ @SuppressWarnings("unchecked") private <V> Cache<V> getThreadCache(String name) { Map<String, Cache<?>> threadCacheMap = threadCacheMapHolder.get(); Cache<V> threadCache = (Cache<V>) threadCacheMap.get(name); if (threadCache == null) { threadCache = new MapCacheImpl<V>(); threadCacheMap.put(name, threadCache); } return threadCache; } /** * Generate a cache bound to the request * * @param name * @return */ @SuppressWarnings("unchecked") private <V> Cache<V> getRequestCache(String name) { Map<String, Cache<?>> requestCacheMap = requestCacheMapHolder.get(); Cache<V> requestCache = (Cache<V>) requestCacheMap.get(name); if (requestCache == null) { requestCache = new MapCacheImpl<V>(); requestCacheMap.put(name, requestCache); } return requestCache; } /** * @param name * @return */ @SuppressWarnings("unchecked") private <V> Cache<V> getInstanceCache(String name) { if (name == null) { return new CacheImpl<V>(cacheManager, null); } else { Cache<V> c = (Cache<V>) caches.get(name); if (c == null) { c = new CacheImpl<V>(cacheManager, name); caches.put(name, c); } return c; } } /** * {@inheritDoc} * * @see org.sakaiproject.nakamura.api.memory.CacheManagerService#unbind(org.sakaiproject.nakamura.api.memory.CacheScope) */ public void unbind(CacheScope scope) { switch (scope) { case REQUEST: unbindRequest(); break; case THREAD: unbindThread(); break; } } /** * */ private void unbindThread() { Map<String, Cache<?>> threadCache = threadCacheMapHolder.get(); for (Cache<?> cache : threadCache.values()) { cache.clear(); } threadCacheMapHolder.remove(); } /** * */ private void unbindRequest() { Map<String, Cache<?>> requestCache = requestCacheMapHolder.get(); for (Cache<?> cache : requestCache.values()) { cache.clear(); } requestCacheMapHolder.remove(); } }