消除过期的对象引用
消除过期的对象引用 考虑以下简单的栈实现: x public class Stack { private Object[] elements; private int size = 0; private static final int DEFAULT_INITIAL_CAPACITY = 16; public Stack() { elements = new Object[DEFAULT_INITIAL_CAPACITY]; } p ublic void push(Object e) { ensureCapacity(); elements[size++] = e; } p ublic Object pop() { if (size == 0) throw new EmptyStackException(); return elements[--size]; } / ** * Ensure space for at least one more element, roughly * doubling the capacity each time the array needs to grow. */ private void ensureCapacity() { if (elements.length == size) elements = Arrays.copyOf