java使用泛型实现一个MyArrayList类

以下是使用泛型实现的MyArrayList类的示例代码：

public class MyArrayList<E> {
    private static final int DEFAULT_CAPACITY = 10;
    private int size;
    private E[] elements;

    public MyArrayList() {
        elements = (E[]) new Object[DEFAULT_CAPACITY];
    }

    public MyArrayList(int capacity) {
        elements = (E[]) new Object[capacity];
    }

    public void add(E e) {
        if (size == elements.length) {
            resize();
        }
        elements[size++] = e;
    }

    public E get(int index) {
        checkIndex(index);
        return elements[index];
    }

    public void set(int index, E e) {
        checkIndex(index);
        elements[index] = e;
    }

    public E remove(int index) {
        checkIndex(index);
        E element = elements[index];
        for (int i = index; i < size - 1; i++) {
            elements[i] = elements[i + 1];
        }
        elements[--size] = null;
        return element;
    }

    public boolean contains(E e) {
        for (int i = 0; i < size; i++) {
            if (elements[i].equals(e)) {
                return true;
            }
        }
        return false;
    }

    public int size() {
        return size;
    }

    public boolean isEmpty() {
        return size == 0;
    }

    private void resize() {
        E[] newElements = (E[]) new Object[elements.length * 2];
        System.arraycopy(elements, 0, newElements, 0, size);
        elements = newElements;
    }

    private void checkIndex(int index) {
        if (index < 0 || index >= size) {
            throw new IndexOutOfBoundsException("Index: " + index + ", Size: " + size);
        }
    }
}

使用示例：

MyArrayList<String> list = new MyArrayList<>();
list.add("hello");
list.add("world");
System.out.println(list.get(0)); // output: hello
list.set(1, "java");
System.out.println(list.get(1)); // output: java
System.out.println(list.remove(0)); // output: hello
System.out.println(list.contains("java")); // output: true
System.out.println(list.size()); // output: 1
System.out.println(list.isEmpty()); // output: false