(A key <tt>k</tt> is reinserted into a map <tt>m</tt> if <tt>m.put(k, v)</tt> is invoked when <tt>m.containsKey(k)</tt> would return <tt>true</tt> immediately prior to the invocation.) A special {@link #LinkedHashMap(int,float,boolean) constructor} is provided to crea...
很容易看出来,细的蓝色箭头,是原来HashMap里本身就有的,而粗的箭头,则是LinkedHashMap新增了,每个Entry实例旁边的数字代表的是插入的顺序。我们可以想象一下,如果我们用左手捏住head节点,右手捏住任意节点,用力拽开,会发现这些Entry实例会变成一个环状结构(注意:其实在第6个Entry实例和Head节点处还有一个双向箭头,...
6. LinkedHashMap Performance HashMap and LinkedHashMap performs the basic operations of add, remove and contains in constant-time performance. LinkedHashMap performs a little wose than HashMap because it has to maintain a doubly-linkedlist and HashMap maintain only linked list. On the other hand...
However, thisconstant-time performance ofLinkedHashMapis likely to be a little worse than the constant-time ofHashMapdue to the added overhead of maintaining a doubly-linked list. Iteration over collection views ofLinkedHashMapalso takes linear timeO(n)similar to that ofHashMap. On the flip s...
LinkedHashMap继承于HashMap,其在JDK中的定义为: publicclassLinkedHashMap<K,V>extendsHashMap<K,V>implementsMap<K,V> { ... } 成员变量定义 与HashMap相比,LinkedHashMap增加了两个属性用于保证迭代顺序,分别是 双向链表头结点header 和 标志位accessOrder (值为true时,表示按照访问顺序迭代;值为false时,表示...
Iteration over a HashMap is likely to be more expensive, requiring time proportional to its capacity. A linked hash map has two parameters that affect its performance: initial capacity and load factor. They are defined precisely as for HashMap. Note, however, that the penalty for choosing ...
Performance is likely to be just slightly below that of HashMap, due to the added expense of maintaining the linked list, with one exception: Iteration over the collection-views of a LinkedHashMap requires time proportional to the size of the map, regardless of its capacity. Iteration over a...
Performance is likely to be just slightly below that of HashMap, due to the added expense of maintaining the linked list, with one exception: Iteration over the collection-views of a LinkedHashMap requires time proportional to the size of the map, regardless of its capacity. Iteration over a...
Recently, @szeiger rewrote the implementations of mutable.HashMap and mutable.HashSet here. So far as I see there's no reason not to implement LinkedHashSet/Maps the same way, and in fact doing so will allow LinkedHashMaps/Sets to partic...
A ConcurrentLinkedHashMap for Java. Contribute to ben-manes/concurrentlinkedhashmap development by creating an account on GitHub.