特殊的Map类-IdentityHashMap与HashMap的区别
java.util.Map的一个实现类是IdentityHashMap,可以根据地址判断key是否相等:
public class IdentityHashMapextends AbstractMapimplements Map, Serializable, Cloneable;// 非一般意义上的映射This class implements the Map interface with a hash table, using reference-equality in place of object-equality when comparing keys (and values). I ...