Java tutorial
/* * 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.ranger.plugin.policyengine; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.util.LinkedHashMap; import java.util.Map; public class CacheMap<K, V> extends LinkedHashMap<K, V> { private static final long serialVersionUID = 1L; private static final Log LOG = LogFactory.getLog(CacheMap.class); private static final float RANGER_CACHE_DEFAULT_LOAD_FACTOR = 0.75f; protected int initialCapacity; public CacheMap(int initialCapacity) { super(initialCapacity, CacheMap.RANGER_CACHE_DEFAULT_LOAD_FACTOR, true); // true for access-order this.initialCapacity = initialCapacity; } @Override protected boolean removeEldestEntry(Map.Entry eldest) { boolean result = size() > initialCapacity; if (LOG.isDebugEnabled()) { LOG.debug("CacheMap.removeEldestEntry(), result:" + result); } return result; } }