1 /* 2 **************************************************************************** 3 * Copyright (c) 2007-2009 International Business Machines Corporation and * 4 * others. All rights reserved. * 5 **************************************************************************** 6 */ 7 8 package com.ibm.icu.impl; 9 10 import java.lang.ref.Reference; 11 import java.lang.ref.SoftReference; 12 import java.lang.ref.WeakReference; 13 import java.util.Collections; 14 import java.util.HashMap; 15 import java.util.Map; 16 17 public class SimpleCache<K, V> implements ICUCache<K, V> { 18 private static final int DEFAULT_CAPACITY = 16; 19 20 private Reference<Map<K, V>> cacheRef = null; 21 private int type = ICUCache.SOFT; 22 private int capacity = DEFAULT_CAPACITY; 23 24 public SimpleCache() { 25 } 26 27 public SimpleCache(int cacheType) { 28 this(cacheType, DEFAULT_CAPACITY); 29 } 30 31 public SimpleCache(int cacheType, int initialCapacity) { 32 if (cacheType == ICUCache.WEAK) { 33 type = cacheType; 34 } 35 if (initialCapacity > 0) { 36 capacity = initialCapacity; 37 } 38 } 39 40 public V get(Object key) { 41 Reference<Map<K, V>> ref = cacheRef; 42 if (ref != null) { 43 Map<K, V> map = ref.get(); 44 if (map != null) { 45 return map.get(key); 46 } 47 } 48 return null; 49 } 50 51 public void put(K key, V value) { 52 Reference<Map<K, V>> ref = cacheRef; 53 Map<K, V> map = null; 54 if (ref != null) { 55 map = ref.get(); 56 } 57 if (map == null) { 58 map = Collections.synchronizedMap(new HashMap<K, V>(capacity)); 59 if (type == ICUCache.WEAK) { 60 ref = new WeakReference<Map<K, V>>(map); 61 } else { 62 ref = new SoftReference<Map<K, V>>(map); 63 } 64 cacheRef = ref; 65 } 66 map.put(key, value); 67 } 68 69 public void clear() { 70 cacheRef = null; 71 } 72 73 } 74
