Java tutorial
/** * Licensed to Jasig under one or more contributor license * agreements. See the NOTICE file distributed with this work * for additional information regarding copyright ownership. * Jasig 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.jasig.portal.utils.cache; import java.io.Serializable; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.LinkedHashMap; import java.util.Map; import java.util.Properties; import org.apache.commons.lang.StringUtils; import org.jasig.portal.utils.Populator; /** * @author Eric Dalquist * @version $Revision$ */ public final class CacheKey implements Serializable { private static final long serialVersionUID = 1L; public static final class CacheKeyBuilder<K extends Serializable, V extends Serializable> implements Populator<K, V> { private final String source; private ArrayList<Serializable> keyList; private Map<Serializable, Serializable> keyMap; private CacheKeyBuilder(String source) { this.source = source; } public CacheKeyBuilder<K, V> add(Serializable v) { checkKeyList(); this.keyList.add(v); return this; } public CacheKeyBuilder<K, V> addAll(Serializable... vs) { checkKeyList(); for (final Serializable v : vs) { this.keyList.add(v); } return this; } public CacheKeyBuilder<K, V> addAll(Collection<Serializable> vs) { checkKeyList(); for (final Serializable v : vs) { this.keyList.add(v); } return this; } public CacheKeyBuilder<K, V> put(K k, V v) { checkKeyMap(); this.keyMap.put(k, v); return this; } public CacheKeyBuilder<K, V> putAll(Properties p) { checkKeyMap(); for (final Map.Entry<Object, Object> ve : p.entrySet()) { this.keyMap.put((String) ve.getKey(), (String) ve.getValue()); } return this; } public CacheKeyBuilder<K, V> putAll(Map<? extends K, ? extends V> vm) { checkKeyMap(); for (final Map.Entry<? extends K, ? extends V> ve : vm.entrySet()) { this.keyMap.put(ve.getKey(), ve.getValue()); } return this; } public int size() { final int listLength = this.keyList != null ? this.keyList.size() : 0; final int mapLength = this.keyMap != null ? this.keyMap.size() : 0; return listLength + mapLength; } public CacheKey build() { final int listLength = this.keyList != null ? this.keyList.size() : 0; final int mapLength = this.keyMap != null ? this.keyMap.size() : 0; final int s = listLength + mapLength; final Serializable[] key = new Serializable[s]; if (listLength > 0) { this.keyList.toArray(key); } if (mapLength > 0) { int mapIndex = listLength; for (final Map.Entry<? extends Serializable, ? extends Serializable> ve : this.keyMap.entrySet()) { key[mapIndex++] = new Serializable[] { ve.getKey(), ve.getValue() }; } } return new CacheKey(this.source, key); } private void checkKeyList() { if (this.keyList == null) { this.keyList = new ArrayList<Serializable>(); } } private void checkKeyMap() { if (this.keyMap == null) { this.keyMap = new LinkedHashMap<Serializable, Serializable>(); } } } public static <K extends Serializable, V extends Serializable> CacheKeyBuilder<K, V> builder(String source) { return new CacheKeyBuilder<K, V>(source); } public static CacheKey build(String source, Serializable... key) { return new CacheKey(source, key.clone()); } public static CacheKey build(String source, Collection<? extends Serializable> key) { return new CacheKey(source, key.toArray(new Serializable[key.size()])); } public static CacheKey build(String source, Map<? extends Serializable, ? extends Serializable> keyData) { final Serializable[] key = new Serializable[keyData.size()]; int mapIndex = 0; for (final Map.Entry<? extends Serializable, ? extends Serializable> ve : keyData.entrySet()) { key[mapIndex++] = new Serializable[] { ve.getKey(), ve.getValue() }; } return new CacheKey(source, key); } private final String source; private final Serializable[] key; private final int hashCode; private CacheKey(String source, Serializable[] key) { this.source = source; this.key = key; this.hashCode = this.internalHashCode(); } public Serializable getKey() { return this.key; } public String getSource() { return this.source; } private int internalHashCode() { final int prime = 31; int result = 1; result = prime * result + Arrays.deepHashCode(key); result = prime * result + ((source == null) ? 0 : source.hashCode()); return result; } @Override public int hashCode() { return this.hashCode; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; CacheKey other = (CacheKey) obj; if (source == null) { if (other.source != null) return false; } else if (!source.equals(other.source)) return false; if (!Arrays.deepEquals(key, other.key)) return false; return true; } private final static ThreadLocal<Integer> DEPTH = new ThreadLocal<Integer>() { @Override protected Integer initialValue() { return 0; } }; @Override public String toString() { int d = DEPTH.get(); DEPTH.set(d + 1); final String indent = StringUtils.leftPad("", DEPTH.get(), '\t'); final String s = indent + "CacheKey [" + this.source + "\n\t" + indent + Arrays.deepToString(this.key) + "\n" + indent + "]"; DEPTH.set(d); return s; } }