How to use

init

method

in

java.util.HashMap

  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 = Collections.roundUpToPowerOfTwo(capacity);
    }
    makeTable(capacity);

    int size = stream.readInt();
    if (size < 0) {
      throw new InvalidObjectException("Size: " + size);
    }

    init(); // Give subclass (LinkedHashMap) a chance to initialize itself
    for (int i = 0; i < size; i++) {
      @SuppressWarnings("unchecked") K key = (K) stream.readObject();
      @SuppressWarnings("unchecked") V val = (V) stream.readObject();
      constructorPut(key, val);
    }
  }
}

/**
 * Returns a shallow copy of this map.
 *
 * @return a shallow copy of this map.
 */
@SuppressWarnings("unchecked")
@Override public Object clone() {
  /*
   * This could be made more efficient. It unnecessarily hashes all of
   * the elements in the map.
   */
  HashMap<K, V> result;
  try {
    result = (HashMap<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.entryForNullKey = null;
  result.size = 0;
  result.keySet = null;
  result.entrySet = null;
  result.values = null;
  result.init(); // Give subclass a chance to initialize itself
  result.constructorPutAll(this); // Calls method overridden in subclass!!
  return result;
}

/**
 * Constructs an empty <tt>HashMap</tt> with the default initial capacity
 * (16) and the default load factor (0.75).
 */
public HashMap() {
  this.loadFactor = DEFAULT_LOAD_FACTOR;
  threshold = (int)(DEFAULT_INITIAL_CAPACITY * DEFAULT_LOAD_FACTOR);
  table = new Entry[DEFAULT_INITIAL_CAPACITY];
  init();
}

/**
 * Constructs an empty <tt>HashMap</tt> with the default initial capacity
 * (16) and the default load factor (0.75).
 */
public HashMap() {
  this.loadFactor = DEFAULT_LOAD_FACTOR;
  threshold = (int)(DEFAULT_INITIAL_CAPACITY * DEFAULT_LOAD_FACTOR);
  table = new Entry[DEFAULT_INITIAL_CAPACITY];
  init();
}

/**
 * Constructs an empty <tt>HashMap</tt> with the specified initial
 * capacity and load factor.
 *
 * @param  initialCapacity the initial capacity
 * @param  loadFactor      the load factor
 * @throws IllegalArgumentException if the initial capacity is negative
 *         or the load factor is nonpositive
 */
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);
  // Find a power of 2 >= initialCapacity
  int capacity = 1;
  while (capacity < initialCapacity)
    capacity <<= 1;
  this.loadFactor = loadFactor;
  threshold = (int)(capacity * loadFactor);
  table = new Entry[capacity];
  init();
}

/**
 * Constructs an empty <tt>HashMap</tt> with the specified initial
 * capacity and load factor.
 *
 * @param  initialCapacity the initial capacity
 * @param  loadFactor      the load factor
 * @throws IllegalArgumentException if the initial capacity is negative
 *         or the load factor is nonpositive
 */
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);
  // Find a power of 2 >= initialCapacity
  int capacity = 1;
  while (capacity < initialCapacity)
    capacity <<= 1;
  this.loadFactor = loadFactor;
  threshold = (int)(capacity * loadFactor);
  table = new Entry[capacity];
  init();
}

  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 = Collections.roundUpToPowerOfTwo(capacity);
    }
    makeTable(capacity);

    int size = stream.readInt();
    if (size < 0) {
      throw new InvalidObjectException("Size: " + size);
    }

    init(); // Give subclass (LinkedHashMap) a chance to initialize itself
    for (int i = 0; i < size; i++) {
      @SuppressWarnings("unchecked") K key = (K) stream.readObject();
      @SuppressWarnings("unchecked") V val = (V) stream.readObject();
      constructorPut(key, val);
    }
  }
}

  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 = Collections.roundUpToPowerOfTwo(capacity);
    }
    makeTable(capacity);

    int size = stream.readInt();
    if (size < 0) {
      throw new InvalidObjectException("Size: " + size);
    }

    init(); // Give subclass (LinkedHashMap) a chance to initialize itself
    for (int i = 0; i < size; i++) {
      @SuppressWarnings("unchecked") K key = (K) stream.readObject();
      @SuppressWarnings("unchecked") V val = (V) stream.readObject();
      constructorPut(key, val);
    }
  }
}

  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 = Collections.roundUpToPowerOfTwo(capacity);
    }
    makeTable(capacity);

    int size = stream.readInt();
    if (size < 0) {
      throw new InvalidObjectException("Size: " + size);
    }

    init(); // Give subclass (LinkedHashMap) a chance to initialize itself
    for (int i = 0; i < size; i++) {
      @SuppressWarnings("unchecked") K key = (K) stream.readObject();
      @SuppressWarnings("unchecked") V val = (V) stream.readObject();
      constructorPut(key, val);
    }
  }
}

  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 = Collections.roundUpToPowerOfTwo(capacity);
    }
    makeTable(capacity);

    int size = stream.readInt();
    if (size < 0) {
      throw new InvalidObjectException("Size: " + size);
    }

    init(); // Give subclass (LinkedHashMap) a chance to initialize itself
    for (int i = 0; i < size; i++) {
      @SuppressWarnings("unchecked") K key = (K) stream.readObject();
      @SuppressWarnings("unchecked") V val = (V) stream.readObject();
      constructorPut(key, val);
    }
  }
}

  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 = Collections.roundUpToPowerOfTwo(capacity);
    }
    makeTable(capacity);

    int size = stream.readInt();
    if (size < 0) {
      throw new InvalidObjectException("Size: " + size);
    }

    init(); // Give subclass (LinkedHashMap) a chance to initialize itself
    for (int i = 0; i < size; i++) {
      @SuppressWarnings("unchecked") K key = (K) stream.readObject();
      @SuppressWarnings("unchecked") V val = (V) stream.readObject();
      constructorPut(key, val);
    }
  }
}

  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 = Collections.roundUpToPowerOfTwo(capacity);
    }
    makeTable(capacity);

    int size = stream.readInt();
    if (size < 0) {
      throw new InvalidObjectException("Size: " + size);
    }

    init(); // Give subclass (LinkedHashMap) a chance to initialize itself
    for (int i = 0; i < size; i++) {
      @SuppressWarnings("unchecked") K key = (K) stream.readObject();
      @SuppressWarnings("unchecked") V val = (V) stream.readObject();
      constructorPut(key, val);
    }
  }
}

/**
 * Returns a shallow copy of this <tt>HashMap</tt> instance: the keys and
 * values themselves are not cloned.
 *
 * @return a shallow copy of this map
 */
public Object clone() {
  HashMap<K,V> result = null;
  try {
    result = (HashMap<K,V>)super.clone();
  } catch (CloneNotSupportedException e) {
    // assert false;
  }
  result.table = new Entry[table.length];
  result.entrySet = null;
  result.modCount = 0;
  result.size = 0;
  result.init();
  result.putAllForCreate(this);
  return result;
}

/**
 * Returns a shallow copy of this <tt>HashMap</tt> instance: the keys and
 * values themselves are not cloned.
 *
 * @return a shallow copy of this map
 */
public Object clone() {
  HashMap<K,V> result = null;
  try {
    result = (HashMap<K,V>)super.clone();
  } catch (CloneNotSupportedException e) {
    // assert false;
  }
  result.table = new Entry[table.length];
  result.entrySet = null;
  result.modCount = 0;
  result.size = 0;
  result.init();
  result.putAllForCreate(this);
  return result;
}

/**
 * Returns a shallow copy of this map.
 *
 * @return a shallow copy of this map.
 */
@SuppressWarnings("unchecked")
@Override public Object clone() {
  /*
   * This could be made more efficient. It unnecessarily hashes all of
   * the elements in the map.
   */
  HashMap<K, V> result;
  try {
    result = (HashMap<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.entryForNullKey = null;
  result.size = 0;
  result.keySet = null;
  result.entrySet = null;
  result.values = null;
  result.init(); // Give subclass a chance to initialize itself
  result.constructorPutAll(this); // Calls method overridden in subclass!!
  return result;
}

/**
 * Returns a shallow copy of this map.
 *
 * @return a shallow copy of this map.
 */
@SuppressWarnings("unchecked")
@Override public Object clone() {
  /*
   * This could be made more efficient. It unnecessarily hashes all of
   * the elements in the map.
   */
  HashMap<K, V> result;
  try {
    result = (HashMap<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.entryForNullKey = null;
  result.size = 0;
  result.keySet = null;
  result.entrySet = null;
  result.values = null;
  result.init(); // Give subclass a chance to initialize itself
  result.constructorPutAll(this); // Calls method overridden in subclass!!
  return result;
}

/**
 * Returns a shallow copy of this map.
 *
 * @return a shallow copy of this map.
 */
@SuppressWarnings("unchecked")
@Override public Object clone() {
  /*
   * This could be made more efficient. It unnecessarily hashes all of
   * the elements in the map.
   */
  HashMap<K, V> result;
  try {
    result = (HashMap<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.entryForNullKey = null;
  result.size = 0;
  result.keySet = null;
  result.entrySet = null;
  result.values = null;
  result.init(); // Give subclass a chance to initialize itself
  result.constructorPutAll(this); // Calls method overridden in subclass!!
  return result;
}

/**
 * Returns a shallow copy of this map.
 *
 * @return a shallow copy of this map.
 */
@SuppressWarnings("unchecked")
@Override public Object clone() {
  /*
   * This could be made more efficient. It unnecessarily hashes all of
   * the elements in the map.
   */
  HashMap<K, V> result;
  try {
    result = (HashMap<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.entryForNullKey = null;
  result.size = 0;
  result.keySet = null;
  result.entrySet = null;
  result.values = null;
  result.init(); // Give subclass a chance to initialize itself
  result.constructorPutAll(this); // Calls method overridden in subclass!!
  return result;
}

/**
 * Returns a shallow copy of this map.
 *
 * @return a shallow copy of this map.
 */
@SuppressWarnings("unchecked")
@Override public Object clone() {
  /*
   * This could be made more efficient. It unnecessarily hashes all of
   * the elements in the map.
   */
  HashMap<K, V> result;
  try {
    result = (HashMap<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.entryForNullKey = null;
  result.size = 0;
  result.keySet = null;
  result.entrySet = null;
  result.values = null;
  result.init(); // Give subclass a chance to initialize itself
  result.constructorPutAll(this); // Calls method overridden in subclass!!
  return result;
}

/**
 * Returns a shallow copy of this map.
 *
 * @return a shallow copy of this map.
 */
@SuppressWarnings("unchecked")
@Override public Object clone() {
  /*
   * This could be made more efficient. It unnecessarily hashes all of
   * the elements in the map.
   */
  HashMap<K, V> result;
  try {
    result = (HashMap<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.entryForNullKey = null;
  result.size = 0;
  result.keySet = null;
  result.entrySet = null;
  result.values = null;
  result.init(); // Give subclass a chance to initialize itself
  result.constructorPutAll(this); // Calls method overridden in subclass!!
  return result;
}