private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
stream.defaultReadObject();
int capacity = stream.readInt();
if (capacity < 0) {
throw new InvalidObjectException("Capacity: " + capacity);
}
if (capacity < MINIMUM_CAPACITY) {
capacity = MINIMUM_CAPACITY;
} else if (capacity > MAXIMUM_CAPACITY) {
capacity = MAXIMUM_CAPACITY;
} else {
capacity = roundUpToPowerOfTwo(capacity);
}
makeTable(capacity);
int size = stream.readInt();
if (size < 0) {
throw new InvalidObjectException("Size: " + size);
}
for (int i = 0; i < size; i++) {
@SuppressWarnings("unchecked")
K key = (K) stream.readObject();
@SuppressWarnings("unchecked")
V val = (V) stream.readObject();
constructorPut(key, val);
}
}
/**
* Constructs a new {@code Hashtable} using the specified capacity and the default load factor.
*
* @param capacity the initial capacity.
*/
public Hashtable(int capacity) {
if (capacity < 0) {
throw new IllegalArgumentException("Capacity: " + capacity);
}
if (capacity == 0) {
@SuppressWarnings("unchecked")
HashtableEntry<K, V>[] tab = (HashtableEntry<K, V>[]) EMPTY_TABLE;
table = tab;
threshold = -1; // Forces first put() to replace EMPTY_TABLE
return;
}
if (capacity < MINIMUM_CAPACITY) {
capacity = MINIMUM_CAPACITY;
} else if (capacity > MAXIMUM_CAPACITY) {
capacity = MAXIMUM_CAPACITY;
} else {
capacity = roundUpToPowerOfTwo(capacity);
}
makeTable(capacity);
}
/**
* Returns a new {@code Hashtable} with the same key/value pairs, capacity and load factor.
*
* @return a shallow copy of this {@code Hashtable}.
* @see java.lang.Cloneable
*/
@SuppressWarnings("unchecked")
@Override
public synchronized Object clone() {
/*
* This could be made more efficient. It unnecessarily hashes all of
* the elements in the map.
*/
Hashtable<K, V> result;
try {
result = (Hashtable<K, V>) super.clone();
} catch (CloneNotSupportedException e) {
throw new AssertionError(e);
}
// Restore clone to empty state, retaining our capacity and threshold
result.makeTable(table.length);
result.size = 0;
result.keySet = null;
result.entrySet = null;
result.values = null;
result.constructorPutAll(this);
return result;
}