Java tutorial
/* * Copyright (c) 2014, WSO2 Inc. (http://www.wso2.org) All Rights Reserved. * * Licensed 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.wso2.carbon.caching.invalidator.amqp; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.wso2.carbon.caching.impl.CacheInvalidator; import org.wso2.carbon.registry.core.utils.UUIDGenerator; import java.io.ByteArrayOutputStream; import java.io.ObjectOutputStream; import java.io.Serializable; /** * Global cache invalidation publisher implements org.wso2.carbon.caching.impl.CacheInvalidator interface */ public class CacheInvalidationPublisher implements CacheInvalidator { private static final Log log = LogFactory.getLog(CacheInvalidationPublisher.class); @Override public void invalidateCache(int tenantId, String cacheManagerName, String cacheName, Serializable cacheKey) { log.debug("Global cache invalidation: initializing the connection"); if (ConfigurationManager.getProviderUrl() == null) { ConfigurationManager.init(); } //Converting data to json string GlobalCacheInvalidationEvent event = new GlobalCacheInvalidationEvent(); event.setTenantId(tenantId); event.setCacheManagerName(cacheManagerName); event.setCacheName(cacheName); event.setCacheKey(cacheKey); String uuid = UUIDGenerator.generateUUID(); event.setUuid(uuid); // Setup the pub/sub connection, session // Send the msg (byte stream) Connection connection = null; try { log.debug("Global cache invalidation: converting serializable object to byte stream."); byte data[] = serialize(event); log.debug("Global cache invalidation: converting data to byte stream complete."); ConnectionFactory factory = new ConnectionFactory(); factory.setHost(ConfigurationManager.getProviderUrl()); connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.exchangeDeclare(ConfigurationManager.getTopicName(), "topic"); channel.basicPublish(ConfigurationManager.getTopicName(), "invalidate.cache", null, data); ConfigurationManager.getSentMsgBuffer().add(uuid.trim()); log.debug("Global cache invalidation message sent: " + new String(data)); } catch (Exception e) { log.error("Global cache invalidation: Error publishing the message", e); } finally { if (connection != null) { try { connection.close(); } catch (Exception e) { log.error("Global cache invalidation: error close publish connection", e); } } } } private byte[] serialize(Object obj) throws Exception { ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); ObjectOutputStream objectOutputStream = new ObjectOutputStream(byteArrayOutputStream); objectOutputStream.writeObject(obj); return byteArrayOutputStream.toByteArray(); } }