java HashMap用法

它存储的内容是键值对(key-value)映射

void                 clear()
Object               clone()
boolean              containsKey(Object key)
boolean              containsValue(Object value)
Set<Entry<K, V>>     entrySet()
V                    get(Object key)
boolean              isEmpty()
Set<K>               keySet()
V                    put(K key, V value)
void                 putAll(Map<? extends K, ? extends V> map)
V                    remove(Object key)
int                  size()
Collection<V>        values()