- private static class ArrayList<E> extends AbstractList<E>
- implements RandomAccess, java.io.Serializable
- {
- private static final long serialVersionUID = -2764017481108945198L;
- private final E[] a;
- ArrayList(E[] array) {
- if (array==null)
- throw new NullPointerException();
- a = array;
- }
- public int size() {
- return a.length;
- }
- public Object[] toArray() {
- return a.clone();
- }
- public <T> T[] toArray(T[] a) {
- int size = size();
- if (a.length <size)
- return Arrays.copyOf(this.a, size,
- (Class<? extends T[]>) a.getClass());
- System.arraycopy(this.a, 0, a, 0, size);
- if (a.length> size)
- a[size] = null;
- return a;
- }
- public E get(int index) {
- return a[index];
- }
- public E set(int index, E element) {
- E oldValue = a[index];
- a[index] = element;
- return oldValue;
- }
- public int indexOf(Object o) {
- if (o==null) {
- for (int i=0; i<a.length; i++)
- if (a[i]==null)
- return i;
- } else {
- for (int i=0; i<a.length; i++)
- if (o.equals(a[i]))
- return i;
- }
- return -1;
- }
- public boolean contains(Object o) {
- return indexOf(o) != -1;
- }
- }
来源: https://www.cnblogs.com/ysocean/p/8616122.html