所以,如果要将自定义的对象放入到LinkedHashMap或LinkedHashSet中,需要@OverridehashCode()和equals()方法。 Hash table and linked list implementation of the <tt>Map</tt> interface, with predictable iteration order. This implementation differs from <tt>HashMap</tt> in that it maintains a doubly-linked...
* properly among the buckets. Performance is likely to be just slightly * below that of <tt>HashMap</tt>, due to the added expense of maintaining the * linked list, with one exception: Iteration over the collection-views * of a <tt>LinkedHashMap</tt> requires time proportional to the ...
publicVput(Kkey, V value) {//当key为null时,调用putForNullKey方法,并将该键值对保存到table的第一个位置if(key==null)returnputForNullKey(value);//根据key的hashCode计算hash值inthash =hash(key.hashCode());//计算该键值对在数组中的存储位置(哪个桶)inti =indexFor(hash, table.length);//在tabl...
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...
HashMap 是基于键散列的映射。它支持 O(1)get / put 操作。键必须具有hashCode()和equals()一致实现才能使其工作。 LinkedHashMap 与 HashMap 非常相似,但它增加了对添加(或访问)项目的顺序的认知,因此迭代顺序与插入顺序(或访问顺序,取决于构造参数)相同。
// ... hashcode, equals, getters methods are omitted ... } As the code shows,thePlayerclass doesn’t implementComparable.Now, let’s initialize aLinkedHashMap<String, Player>: static LinkedHashMap<String, Player> PLAYERS = new LinkedHashMap<>(); ...
Recently,@szeigerrewrote the implementations ofmutable.HashMapandmutable.HashSethere. 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 participate in hashcode sharing between: ...
equals, hashCode, keySet, toString, values Methods inherited from class java.lang.Object finalize, getClass, notify, notifyAll, wait, wait, wait Methods inherited from interface java.util.Map compute, computeIfAbsent, computeIfPresent, containsKey, entrySet, equals, forEac...
put get Returns the value to which the specified key is mapped, or null if this map contains no mapping for entrySet keySet values size remove containsKey isEmpty putAll equals putAll, equals, hashCode, containsValue, toString, clone, forEach, computeIfAbsent, putIfAbsent ...
The situation is much less serious here, because String.hashCode() returns a consistent value that does not depend on object identity. However, that is not the only failure mode. Depending on your JVM's HashMap implementation, tables can be rehashed in ways which may be GC-dependent. And ...