Java tutorial
/* * Copyright 2005,2012 WSO2, Inc. http://www.wso2.org * * 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.logging.appender; import com.google.common.cache.CacheBuilder; import com.google.common.cache.CacheLoader; import com.google.common.cache.LoadingCache; import java.util.concurrent.ExecutionException; import java.util.concurrent.TimeUnit; public class StreamDefinitionCache { private static volatile LoadingCache<String, StreamData> streamIdLoadingCache; private static void init() { if (streamIdLoadingCache != null) { return; } synchronized (StreamDefinitionCache.class) { if (streamIdLoadingCache != null) { return; } streamIdLoadingCache = CacheBuilder.newBuilder().maximumSize(1000) .expireAfterAccess(120, TimeUnit.MINUTES).build(new CacheLoader<String, StreamData>() { @Override public StreamData load(String tenantId) throws Exception { return new StreamData(tenantId, ""); } }); } } public static StreamData getStream(String tenantId) throws ExecutionException { init(); return streamIdLoadingCache.get(tenantId); } public static void putStream(String tenantId, String streamId, String date) { init(); streamIdLoadingCache.put(tenantId, new StreamData(streamId, date)); } }