LRUCache cache = new LRUCache( 2 /* 缓存容量 */ ); cache.put(1, 1); cache.put(2, 2); cache.get(1); // 返回 1 cache.put(3, 3); // 该操作会使得关键字 2 作废 cache.get(2); // 返回 -1 (未找到) cache.put(4, 4); // 该操作会使得关键字 1 作废 cache.get(1); //...
如下所示,笔者使用LinkedHashMap实现一个符合LRU算法的数据结构,该结构最多可以缓存6个元素,但元素多余六个时,会自动删除最近最久没有被使用的元素,如下所示: public class LRU<K,V> extends LinkedHashMap<K, V> implements Map<K, V>{ private static final long serialVersionUID = 1L; public LRU(int ...
publicCachebuild(){setDefaultImplementations();// 不管什么缓存这里都会加载 PerpetualCacheCachecache=newBaseCacheInstance(implementation,id);setCacheProperties(cache);// issue #352, do not apply decorators to custom caches// 默认是Lru 如果不配置类型的话if(PerpetualCache.class.equals(cache.getClass()))...
//创建新的Entry,并插入到LinkedHashMap中createEntry(hash, key, value, bucketIndex);// 重写了HashMap中的createEntry方法//双向链表的第一个有效节点(header后的那个节点)为最近最少使用的节点,这是用来支持LRU算法的Entry<K,V> eldest = header.after;//如果有必要,则删除掉该近期最少使用的节点,//这要...
此外,LinkedHashMap 也是 Map 的一个非同步的实现。此外,LinkedHashMap还可以用来实现LRU (Least recently used, 最近最少使用)算法,这个问题会在下文的特别谈到。 LinkedHashMap 在 JDK 中的定义 类结构定义 LinkedHashMap继承于HashMap,其在JDK中的定义为: ...
Just likeHashMap,LinkedHashMapimplementation is not synchronized. So if you are going to access it from multiple threads and at least one of these threads is likely to change it structurally, then it must be externally synchronized. It's best to do this at creation: ...
Implementation Note: The spliterators returned by the spliterator method of the collections returned by all of this class's collection view methods are created from the iterators of the corresponding collections. Since: 1.4 See Also: Object.hashCode(),Collection,Map,HashMap,TreeMap,Hashtable,Serializ...
Image Cache Introduction In this implementation, the image cache is created using Java's LinkedHashMap as a Read Through Cache. It provides a method called as load which behaves as below: Check : will check if the given key is present in the cache, if not present a cache miss is recorde...
当然,首先并不着急看源码,第一步,需要确认glide源码中的LRU缓存和用LinkedHashMap实现的LRU是不是具有同样的功能,把它的注释看一遍。 ❝ An BitmapPool implementation that uses an LruPoolStrategy to bucket Bitmaps and then uses an LRU eviction policy to evict Bitmaps from the least recently used bucke...
implementsMap<K,V> { //implementation } 2. LinkedHashMap Features The important things to learn about Java LinkedHashMap class are: It stores key-value pairs similar to HashMap. It contains only unique keys. Duplicate keys are not allowed. ...