* <code>null</code> *@seeObject#equals(Object) *@see#get(Object)*/publicsynchronizedV put(K key, V value) {//Make sure the value is not nullif(value ==null) {thrownewNullPointerException(); }//Makes sure the key
Hashtable的实现原理跟HashMap的实现原理(Java 8之前)是一样的,里面的数据结构同样是一个数组+链表的结构。首先来看一下put的源码 /** * Maps the specified <code>key</code> to the specified * <code>value</code> in this hashtable. Neither the key nor the * value can be <code>null</code>....
,?>[] oldMap = table;// overflow-conscious code// 扩容成2倍+1intnewCapacity=(oldCapacity <<1) +1;// 这里判断是否超出了容量限制if(newCapacity - MAX_ARRAY_SIZE >0) {if(oldCapacity == MAX_ARRAY_SIZE)// Keep running with MAX_ARRAY_SIZE bucketsreturn;// 最大容量 MAX_ARRAY_SIZEnewC...
Hashtable 是在 Java 1.0 的时候创建的，而集合的统一规范命名是在后来的 Java 2 开始约定的，当时...
代码语言:java AI代码解释 publicsynchronizedVput(Kkey,Vvalue){// Make sure the value is not nullif(value==null){thrownewNullPointerException();}// Increase the modCountmodCount++;// Resize the Hashtable if necessaryif(count>=threshold){resize(2*table.length);}// Get the hash code of th...
Java的HashMap和HashTable 1. HashMap 1) hashmap的数据结构 Hashmap是一个数组和链表的结合体(在数据结构称“链表散列“),如下图示: 当我们往hashmap中put元素的时候,先根据key的hash值得到这个元素在数组中的位置(即下标),然后就可以把这个元素放到对应的位置中了。如果这个元素所在的位子上已经存放有其他元素...
HashMap and Hashtable both implement java.Util.Map interface but there are some differences that Java developers must understand to write more dfficient code. As of the java2 platform v1.2, Hashtable class was retrofitted to implement the Map interface, making it a member of the java Collectio...
hashCode()Returns the hash code value for this Map as per the definition in the Map interface.booleanisEmpty()Tests if this hashtable maps no keys to values.Enumeration<K>keys()Returns an enumeration of the keys in this hashtable.Set<K>keySet()...
hashCodein interfaceMap<K,V> Overrides: hashCodein classObject Returns: a hash code value for this object. Since: 1.2 See Also: Map.hashCode() compute publicVcompute(Kkey,BiFunction<? superK,? superV,? extendsV> remappingFunction) ...
Entry<?,?>[] oldMap = table;// overflow-conscious codeintnewCapacity=(oldCapacity <<1) +1;if(newCapacity - MAX_ARRAY_SIZE >0) {if(oldCapacity == MAX_ARRAY_SIZE)// 已经超出MAX_ARRAY_SIZE了就没办法扩容了return; newCapacity = MAX_ARRAY_SIZE; ...