java.util.ArrayList Maven / Gradle / Ivy
/*
* Copyright 2016 Carlos Ballesteros Velasco
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.util;
import jtransc.internal.GenericListIterator;
public class ArrayList extends AbstractList implements List, RandomAccess, Cloneable, java.io.Serializable {
private static final int DEFAULT_CAPACITY = 10;
private static final Object[] EMPTY_ELEMENTDATA = {};
private static final Object[] DEFAULTCAPACITY_EMPTY_ELEMENTDATA = {};
transient Object[] elementData; // non-private to simplify nested class access
private int size;
public ArrayList(int initialCapacity) {
if (initialCapacity > 0) {
this.elementData = new Object[initialCapacity];
} else if (initialCapacity == 0) {
this.elementData = EMPTY_ELEMENTDATA;
} else {
throw new IllegalArgumentException("Illegal Capacity: " + initialCapacity);
}
}
public ArrayList() {
this.elementData = DEFAULTCAPACITY_EMPTY_ELEMENTDATA;
}
public ArrayList(Collection c) {
elementData = c.toArray();
if ((size = elementData.length) != 0) {
if (elementData.getClass() != Object[].class) elementData = Arrays.copyOf(elementData, size, Object[].class);
} else {
this.elementData = EMPTY_ELEMENTDATA;
}
}
public void trimToSize() {
modCount++;
if (size < elementData.length) {
elementData = (size == 0) ? EMPTY_ELEMENTDATA : Arrays.copyOf(elementData, size);
}
}
public void ensureCapacity(int minCapacity) {
int minExpand = (elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA) ? 0 : DEFAULT_CAPACITY;
if (minCapacity > minExpand) ensureExplicitCapacity(minCapacity);
}
private void ensureCapacityInternal(int minCapacity) {
if (elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA) minCapacity = Math.max(DEFAULT_CAPACITY, minCapacity);
ensureExplicitCapacity(minCapacity);
}
private void ensureExplicitCapacity(int minCapacity) {
modCount++;
if (minCapacity - elementData.length > 0) grow(minCapacity);
}
private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
private void grow(int minCapacity) {
int oldCapacity = elementData.length;
int newCapacity = oldCapacity + (oldCapacity >> 1);
if (newCapacity - minCapacity < 0) newCapacity = minCapacity;
if (newCapacity - MAX_ARRAY_SIZE > 0) newCapacity = hugeCapacity(minCapacity);
elementData = Arrays.copyOf(elementData, newCapacity);
}
private static int hugeCapacity(int minCapacity) {
if (minCapacity < 0) throw new OutOfMemoryError();
return (minCapacity > MAX_ARRAY_SIZE) ? Integer.MAX_VALUE : MAX_ARRAY_SIZE;
}
public int size() {
return size;
}
public boolean isEmpty() {
return size == 0;
}
public boolean contains(Object o) {
return indexOf(o) >= 0;
}
public int indexOf(Object o) {
if (o == null) {
for (int i = 0; i < size; i++) if (elementData[i] == null) return i;
} else {
for (int i = 0; i < size; i++) if (o.equals(elementData[i])) return i;
}
return -1;
}
public int lastIndexOf(Object o) {
if (o == null) {
for (int i = size - 1; i >= 0; i--) if (elementData[i] == null) return i;
} else {
for (int i = size - 1; i >= 0; i--) if (o.equals(elementData[i])) return i;
}
return -1;
}
public Object clone() {
try {
ArrayList v = (ArrayList) super.clone();
v.elementData = Arrays.copyOf(elementData, size);
v.modCount = 0;
return v;
} catch (CloneNotSupportedException e) {
throw new InternalError(e);
}
}
public Object[] toArray() {
return Arrays.copyOf(elementData, size);
}
@SuppressWarnings("unchecked")
public T[] toArray(T[] a) {
if (a.length < size) return (T[]) Arrays.copyOf(elementData, size, a.getClass());
System.arraycopy(elementData, 0, a, 0, size);
if (a.length > size) a[size] = null;
return a;
}
@SuppressWarnings("unchecked")
E elementData(int index) {
return (E) elementData[index];
}
public E get(int index) {
rangeCheck(index);
return elementData(index);
}
public E set(int index, E element) {
rangeCheck(index);
E oldValue = elementData(index);
elementData[index] = element;
return oldValue;
}
public boolean add(E e) {
ensureCapacityInternal(size + 1);
elementData[size++] = e;
return true;
}
public void add(int index, E element) {
rangeCheckForAdd(index);
ensureCapacityInternal(size + 1);
System.arraycopy(elementData, index, elementData, index + 1, size - index);
elementData[index] = element;
size++;
}
public E remove(int index) {
rangeCheck(index);
modCount++;
E oldValue = elementData(index);
int numMoved = size - index - 1;
if (numMoved > 0) System.arraycopy(elementData, index + 1, elementData, index, numMoved);
elementData[--size] = null;
return oldValue;
}
public boolean remove(Object o) {
if (o == null) {
for (int index = 0; index < size; index++) {
if (elementData[index] == null) {
fastRemove(index);
return true;
}
}
} else {
for (int index = 0; index < size; index++) {
if (o.equals(elementData[index])) {
fastRemove(index);
return true;
}
}
}
return false;
}
private void fastRemove(int index) {
modCount++;
int numMoved = size - index - 1;
if (numMoved > 0) System.arraycopy(elementData, index + 1, elementData, index, numMoved);
elementData[--size] = null; // clear to let GC do its work
}
public void clear() {
modCount++;
for (int i = 0; i < size; i++) elementData[i] = null;
size = 0;
}
public boolean addAll(Collection c) {
Object[] a = c.toArray();
int numNew = a.length;
ensureCapacityInternal(size + numNew); // Increments modCount
System.arraycopy(a, 0, elementData, size, numNew);
size += numNew;
return numNew != 0;
}
public boolean addAll(int index, Collection c) {
rangeCheckForAdd(index);
Object[] a = c.toArray();
int numNew = a.length;
ensureCapacityInternal(size + numNew);
int numMoved = size - index;
if (numMoved > 0) System.arraycopy(elementData, index, elementData, index + numNew, numMoved);
System.arraycopy(a, 0, elementData, index, numNew);
size += numNew;
return numNew != 0;
}
protected void removeRange(int fromIndex, int toIndex) {
modCount++;
int numMoved = size - toIndex;
System.arraycopy(elementData, toIndex, elementData, fromIndex, numMoved);
int newSize = size - (toIndex - fromIndex);
for (int i = newSize; i < size; i++) elementData[i] = null;
size = newSize;
}
private void rangeCheck(int index) {
if (index >= size) throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
}
private void rangeCheckForAdd(int index) {
if (index > size || index < 0) throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
}
private String outOfBoundsMsg(int index) {
return "Index: " + index + ", Size: " + size;
}
public boolean removeAll(Collection c) {
Objects.requireNonNull(c);
return batchRemove(c, false);
}
public boolean retainAll(Collection c) {
Objects.requireNonNull(c);
return batchRemove(c, true);
}
private boolean batchRemove(Collection c, boolean complement) {
final Object[] elementData = this.elementData;
int r = 0, w = 0;
boolean modified = false;
try {
for (; r < size; r++) if (c.contains(elementData[r]) == complement) elementData[w++] = elementData[r];
} finally {
if (r != size) {
System.arraycopy(elementData, r, elementData, w, size - r);
w += size - r;
}
if (w != size) {
for (int i = w; i < size; i++) elementData[i] = null;
modCount += size - w;
size = w;
modified = true;
}
}
return modified;
}
public ListIterator listIterator(int index) {
if (index < 0 || index > size) throw new IndexOutOfBoundsException("Index: " + index);
return new GenericListIterator(this, index);
}
public ListIterator listIterator() {
return listIterator(0);
}
public Iterator iterator() {
return listIterator();
}
public List subList(int fromIndex, int toIndex) {
return super.subList(fromIndex, toIndex);
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy