implements Map<K,V>, Cloneable, Serializable {

private static final long serialVersionUID = 362498820763181265L;

/*

/**

static final int DEFAULT_INITIAL_CAPACITY = 1 << 4; // aka 16

/**

static final int MAXIMUM_CAPACITY = 1 << 30;

/**

static final float DEFAULT_LOAD_FACTOR = 0.75f;

/**

static final int TREEIFY_THRESHOLD = 8;

/**

static final int UNTREEIFY_THRESHOLD = 6;

/**

static final int MIN_TREEIFY_CAPACITY = 64;

/**

static class Node<K,V> implements Map.Entry<K,V> {

final int hash;

final K key;

V value;

Node<K,V> next;

Node(int hash, K key, V value, Node<K,V> next) {

this.hash = hash;

this.key = key;

this.value = value;

this.next = next;

}

public final K getKey() { return key; }

public final V getValue() { return value; }

public final String toString() { return key + "=" + value; }

public final int hashCode() {

return Objects.hashCode(key) ^ Objects.hashCode(value);

}

public final V setValue(V newValue) {

V oldValue = value;

value = newValue;

return oldValue;

}

public final boolean equals(Object o) {

if (o == this)

return true;

if (o instanceof Map.Entry) {

Map.Entry<?,?> e = (Map.Entry<?,?>)o;

if (Objects.equals(key, e.getKey()) &&

Objects.equals(value, e.getValue()))

return true;

}

return false;

}

}

/* ---------------- Static utilities -------------- */

/**

static final int hash(Object key) {

int h;

return (key == null) ? 0 : (h = key.hashCode()) ^ (h >>> 16);

}

/**

static Class<?> comparableClassFor(Object x) {

if (x instanceof Comparable) {

Class<?> c; Type[] ts, as; Type t; ParameterizedType p;

if ((c = x.getClass()) == String.class) // bypass checks

return c;

if ((ts = c.getGenericInterfaces()) != null) {

for (int i = 0; i < ts.length; ++i) {

if (((t = ts[i]) instanceof ParameterizedType) &&

((p = (ParameterizedType)t).getRawType() ==

Comparable.class) &&

(as = p.getActualTypeArguments()) != null &&

as.length == 1 && as[0] == c) // type arg is c

return c;

}

}

}

return null;

}

/**

@SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable

static int compareComparables(Class<?> kc, Object k, Object x) {

return (x == null || x.getClass() != kc ? 0 :

((Comparable)k).compareTo(x));

}

/**

static final int tableSizeFor(int cap) {

int n = cap - 1;

n |= n >>> 1;

n |= n >>> 2;

n |= n >>> 4;

n |= n >>> 8;

n |= n >>> 16;

return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;

}

/* ---------------- Fields -------------- */

/**

transient Node<K,V>[] table;

/**

transient Set<Map.Entry<K,V>> entrySet;

/**

transient int size;

/**

transient int modCount;

/**

// (The javadoc description is true upon serialization.

// Additionally, if the table array has not been allocated, this

// field holds the initial array capacity, or zero signifying

// DEFAULT_INITIAL_CAPACITY.)

int threshold;

/**

final float loadFactor;

/* ---------------- Public operations -------------- */

/**

public HashMap(int initialCapacity, float loadFactor) {

if (initialCapacity < 0)

throw new IllegalArgumentException("Illegal initial capacity: " +

initialCapacity);

if (initialCapacity > MAXIMUM_CAPACITY)

initialCapacity = MAXIMUM_CAPACITY;

if (loadFactor <= 0 || Float.isNaN(loadFactor))

throw new IllegalArgumentException("Illegal load factor: " +

loadFactor);

this.loadFactor = loadFactor;

this.threshold = tableSizeFor(initialCapacity);

}

/**

public HashMap(int initialCapacity) {

this(initialCapacity, DEFAULT_LOAD_FACTOR);

}

/**

public HashMap() {

this.loadFactor = DEFAULT_LOAD_FACTOR; // all other fields defaulted

}

/**

public HashMap(Map<? extends K, ? extends V> m) {

this.loadFactor = DEFAULT_LOAD_FACTOR;

putMapEntries(m, false);

}

/**

final void putMapEntries(Map<? extends K, ? extends V> m, boolean evict) {

int s = m.size();

if (s > 0) {

if (table == null) { // pre-size

float ft = ((float)s / loadFactor) + 1.0F;

int t = ((ft < (float)MAXIMUM_CAPACITY) ?

(int)ft : MAXIMUM_CAPACITY);

if (t > threshold)

threshold = tableSizeFor(t);

}

else if (s > threshold)

resize();

for (Map.Entry<? extends K, ? extends V> e : m.entrySet()) {

K key = e.getKey();

V value = e.getValue();

putVal(hash(key), key, value, false, evict);

}

}

}

/**

public int size() {

return size;

}

/**

public boolean isEmpty() {

return size == 0;

}

/**

public V get(Object key) {

Node<K,V> e;

return (e = getNode(hash(key), key)) == null ? null : e.value;

}

/**

final Node<K,V> getNode(int hash, Object key) {

Node<K,V>[] tab; Node<K,V> first, e; int n; K k;

if ((tab = table) != null && (n = tab.length) > 0 &&

(first = tab[(n - 1) & hash]) != null) {

if (first.hash == hash && // always check first node

((k = first.key) == key || (key != null && key.equals(k))))

return first;

if ((e = first.next) != null) {

if (first instanceof TreeNode)

return ((TreeNode<K,V>)first).getTreeNode(hash, key);

do {

if (e.hash == hash &&

((k = e.key) == key || (key != null && key.equals(k))))

return e;

} while ((e = e.next) != null);

}

}

return null;

}

/**

public boolean containsKey(Object key) {

return getNode(hash(key), key) != null;

}

/**

public V put(K key, V value) {

return putVal(hash(key), key, value, false, true);

}

/**

final V putVal(int hash, K key, V value, boolean onlyIfAbsent,

boolean evict) {

Node<K,V>[] tab; Node<K,V> p; int n, i;

if ((tab = table) == null || (n = tab.length) == 0)

n = (tab = resize()).length;

if ((p = tab[i = (n - 1) & hash]) == null)

tab[i] = newNode(hash, key, value, null);

else {

Node<K,V> e; K k;

if (p.hash == hash &&

((k = p.key) == key || (key != null && key.equals(k))))

e = p;

else if (p instanceof TreeNode)

e = ((TreeNode<K,V>)p).putTreeVal(this, tab, hash, key, value);

else {

for (int binCount = 0; ; ++binCount) {

if ((e = p.next) == null) {

p.next = newNode(hash, key, value, null);

if (binCount >= TREEIFY_THRESHOLD - 1) // -1 for 1st

treeifyBin(tab, hash);

break;

}

if (e.hash == hash &&

((k = e.key) == key || (key != null && key.equals(k))))

break;

p = e;

}

}

if (e != null) { // existing mapping for key

V oldValue = e.value;

if (!onlyIfAbsent || oldValue == null)

e.value = value;

afterNodeAccess(e);

return oldValue;

}

}

++modCount;

if (++size > threshold)

resize();

afterNodeInsertion(evict);

return null;

}

/**

final Node<K,V>[] resize() {

Node<K,V>[] oldTab = table;

int oldCap = (oldTab == null) ? 0 : oldTab.length;

int oldThr = threshold;

int newCap, newThr = 0;

if (oldCap > 0) {

if (oldCap >= MAXIMUM_CAPACITY) {

threshold = Integer.MAX_VALUE;

return oldTab;

}

else if ((newCap = oldCap << 1) < MAXIMUM_CAPACITY &&

oldCap >= DEFAULT_INITIAL_CAPACITY)

newThr = oldThr << 1; // double threshold

}

else if (oldThr > 0) // initial capacity was placed in threshold

newCap = oldThr;

else { // zero initial threshold signifies using defaults

newCap = DEFAULT_INITIAL_CAPACITY;

newThr = (int)(DEFAULT_LOAD_FACTOR * DEFAULT_INITIAL_CAPACITY);

}

if (newThr == 0) {

float ft = (float)newCap * loadFactor;

newThr = (newCap < MAXIMUM_CAPACITY && ft < (float)MAXIMUM_CAPACITY ?

(int)ft : Integer.MAX_VALUE);

}

threshold = newThr;

@SuppressWarnings({"rawtypes","unchecked"})

Node<K,V>[] newTab = (Node<K,V>[])new Node[newCap];

table = newTab;

if (oldTab != null) {

for (int j = 0; j < oldCap; ++j) {

Node<K,V> e;

if ((e = oldTab[j]) != null) {

oldTab[j] = null;

if (e.next == null)

newTab[e.hash & (newCap - 1)] = e;

else if (e instanceof TreeNode)

((TreeNode<K,V>)e).split(this, newTab, j, oldCap);

else { // preserve order

Node<K,V> loHead = null, loTail = null;

Node<K,V> hiHead = null, hiTail = null;

Node<K,V> next;

do {

next = e.next;

if ((e.hash & oldCap) == 0) {

if (loTail == null)

loHead = e;

else

loTail.next = e;

loTail = e;

}

else {

if (hiTail == null)

hiHead = e;

else

hiTail.next = e;

hiTail = e;

}

} while ((e = next) != null);

if (loTail != null) {

loTail.next = null;

newTab[j] = loHead;

}

if (hiTail != null) {

hiTail.next = null;

newTab[j + oldCap] = hiHead;

}

}

}

}

}

return newTab;

}

/**

final void treeifyBin(Node<K,V>[] tab, int hash) {

int n, index; Node<K,V> e;

if (tab == null || (n = tab.length) < MIN_TREEIFY_CAPACITY)

resize();

else if ((e = tab[index = (n - 1) & hash]) != null) {

TreeNode<K,V> hd = null, tl = null;

do {

TreeNode<K,V> p = replacementTreeNode(e, null);

if (tl == null)

hd = p;

else {

p.prev = tl;

tl.next = p;

}

tl = p;

} while ((e = e.next) != null);

if ((tab[index] = hd) != null)

hd.treeify(tab);

}

}

/**

public void putAll(Map<? extends K, ? extends V> m) {

putMapEntries(m, true);

}

/**

public V remove(Object key) {

Node<K,V> e;

return (e = removeNode(hash(key), key, null, false, true)) == null ?

null : e.value;

}

/**

final Node<K,V> removeNode(int hash, Object key, Object value,

boolean matchValue, boolean movable) {

Node<K,V>[] tab; Node<K,V> p; int n, index;

if ((tab = table) != null && (n = tab.length) > 0 &&

(p = tab[index = (n - 1) & hash]) != null) {

Node<K,V> node = null, e; K k; V v;

if (p.hash == hash &&

((k = p.key) == key || (key != null && key.equals(k))))

node = p;

else if ((e = p.next) != null) {

if (p instanceof TreeNode)

node = ((TreeNode<K,V>)p).getTreeNode(hash, key);

else {

do {

if (e.hash == hash &&

((k = e.key) == key ||

(key != null && key.equals(k)))) {

node = e;

break;

}

p = e;

} while ((e = e.next) != null);

}

}

if (node != null && (!matchValue || (v = node.value) == value ||

(value != null && value.equals(v)))) {

if (node instanceof TreeNode)

((TreeNode<K,V>)node).removeTreeNode(this, tab, movable);

else if (node == p)

tab[index] = node.next;

else

p.next = node.next;

++modCount;

--size;

afterNodeRemoval(node);

return node;

}

}

return null;

}

/**

public void clear() {

Node<K,V>[] tab;

modCount++;

if ((tab = table) != null && size > 0) {

size = 0;

for (int i = 0; i < tab.length; ++i)

tab[i] = null;

}

}

/**

public boolean containsValue(Object value) {

Node<K,V>[] tab; V v;

if ((tab = table) != null && size > 0) {

for (int i = 0; i < tab.length; ++i) {

for (Node<K,V> e = tab[i]; e != null; e = e.next) {

if ((v = e.value) == value ||

(value != null && value.equals(v)))

return true;

}

}

}

return false;

}

/**

public Set<K> keySet() {

Set<K> ks;

return (ks = keySet) == null ? (keySet = new KeySet()) : ks;

}

final class KeySet extends AbstractSet<K> {

public final int size() { return size; }

public final void clear() { HashMap.this.clear(); }

public final Iterator<K> iterator() { return new KeyIterator(); }

public final boolean contains(Object o) { return containsKey(o); }

public final boolean remove(Object key) {

return removeNode(hash(key), key, null, false, true) != null;

}

public final Spliterator<K> spliterator() {

return new KeySpliterator<>(HashMap.this, 0, -1, 0, 0);

}

public final void forEach(Consumer<? super K> action) {

Node<K,V>[] tab;

if (action == null)

throw new NullPointerException();

if (size > 0 && (tab = table) != null) {

int mc = modCount;

for (int i = 0; i < tab.length; ++i) {

for (Node<K,V> e = tab[i]; e != null; e = e.next)

action.accept(e.key);

}

if (modCount != mc)

throw new ConcurrentModificationException();

}

}

}

/**

public Collection<V> values() {

Collection<V> vs;

return (vs = values) == null ? (values = new Values()) : vs;

}

final class Values extends AbstractCollection<V> {

public final int size() { return size; }

public final void clear() { HashMap.this.clear(); }

public final Iterator<V> iterator() { return new ValueIterator(); }

public final boolean contains(Object o) { return containsValue(o); }

public final Spliterator<V> spliterator() {

return new ValueSpliterator<>(HashMap.this, 0, -1, 0, 0);

}

public final void forEach(Consumer<? super V> action) {

Node<K,V>[] tab;

if (action == null)

throw new NullPointerException();

if (size > 0 && (tab = table) != null) {

int mc = modCount;

for (int i = 0; i < tab.length; ++i) {

for (Node<K,V> e = tab[i]; e != null; e = e.next)

action.accept(e.value);

}

if (modCount != mc)

throw new ConcurrentModificationException();

}

}

}

/**

public Set<Map.Entry<K,V>> entrySet() {

Set<Map.Entry<K,V>> es;

return (es = entrySet) == null ? (entrySet = new EntrySet()) : es;

}

final class EntrySet extends AbstractSet<Map.Entry<K,V>> {

public final int size() { return size; }

public final void clear() { HashMap.this.clear(); }

public final Iterator<Map.Entry<K,V>> iterator() {

return new EntryIterator();

}

public final boolean contains(Object o) {

if (!(o instanceof Map.Entry))

return false;

Map.Entry<?,?> e = (Map.Entry<?,?>) o;

Object key = e.getKey();

Node<K,V> candidate = getNode(hash(key), key);

return candidate != null && candidate.equals(e);

}

public final boolean remove(Object o) {

if (o instanceof Map.Entry) {

Map.Entry<?,?> e = (Map.Entry<?,?>) o;

Object key = e.getKey();

Object value = e.getValue();

return removeNode(hash(key), key, value, true, true) != null;