privatestaticclassEntry<K,V>extendsHashMap.Entry<K,V>{// These fields comprise the doubly linked list used for iteration.Entry<K,V> before, after;Entry(int hash,Kkey,Vvalue,HashMap.Entry<K,V> next) {super(hash, key, value, next); } ... } 形象地,HashMap与LinkedHashMap的Entry结构...
If no such object exists, the map should be "wrapped" using the {@link Collections#synchronizedMap Collections.synchronizedMap} method. LinkedHashMap是线程非同步的; 如果多个线程并发访问LinkedHashMap,需要在外部同步; 同步方式:Collections.synchronizedMap; The iterators returned by the <tt>iterator</tt> ...
boolean containsValue(Object key):如果指定值映射到映射中的至少一个键,则返回’true’。 Object get(Object key):检索由指定键映射的值。 Object remove(Object key):如果存在,从映射中删除指定键的键值对。 boolean removeEldestEntry(Map.Entry eldest):当映射从访问顺序映射中删除其最老的条目时,返回’true’。
LinkedHashMap采用的hash算法和HashMap相同,但是它重新定义了数组中保存的元素Entry,该Entry除了保存当前对象的引用外,还保存了其上一个元素before和下一个元素after的引用,从而在哈希表的基础上又构成了双向链接列表。看源代码: /*** The iteration ordering method for this linked hash map: <tt>true</tt> * ...
Notice that theEntryclass simply adds two pointers;beforeandafterwhich enable it to hook itself to the linked list. Aside from that, it uses theEntryclass implementation of a the HashMap. Finally, remember that this linked list defines the order of iteration, which by default is the order of...
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...
In access ordered map, keys are sorted on the basis of access order last time they were accessed using any method of LinkedHashMap. Invoking the put, putIfAbsent, get, getOrDefault, compute, computeIfAbsent, computeIfPresent, or merge methods results in an access to the corresponding entry....
The least recently inserted entry (the eldest) is first, and the youngest entry is last. Note that encounter order is not affected if a key is re-inserted into the map with the put method. (A key k is reinserted into a map m if m.put(k, v) is invoked when m.containsKey(k) ...
I am also implementing the below method.. protected boolean removeEldestEntry(Map.Entry eldest) { // System.out.println("removeEldestEntry" +eldest); return size() > MAX_ENTRIES; } After i add 20 items using the put items..to the map.. ...
method 'size' overriden inline method 'computeHash' added inline method 'index' added inline metod 'findNode' added to find an entry for input key(k) in array 'table' API methods overriden: sizeHint, addAll, remove abstract iterator class HashMapIterator added ...