public class Collection {
	private Object[] obj;

	public Object[] getObj() {
		return obj;
	}

	public void setObj(Object[] obj) {
		this.obj = obj;
	}

	public boolean isEmpty() {
		return obj.length > 0 ? false : true;
	};

	public void makeEmpty() {
		obj = new Object[] {};
	}

	public void insert(Object o) {
		//扩展数组容量
		Object[] temp = new Object[obj.length + 1];
		//拷贝原有数组
		for (int i = 0; i < obj.length; i++) {
			temp[i] = obj[i];
		}
		//末位添加新元素
		temp[obj.length] = o;
		obj = temp;
	}

	public boolean isPresent(Object o) {
		if (obj.length == 0) {
			return false;
		}
		//遍历判断
		for (Object ob : obj) {
			if (o.equals(ob))
				return true;
		}
		return false;
	}

	/**
	 * <p>
	 * 此处写的很复杂，应该有更简单的方法实现
	 * </p>
	 */
	public void remove(Object o) {
		if (obj.length == 0) {
			return;
		}
		int count = 0;
		for (int i = 0; i < obj.length; i++) {
			if (o.equals(obj[i])) {
				obj[i] = null;
				count++;
			}
		}

		Object[] temp = new Object[obj.length - count];
		int i = 0;
		for (Object ob : obj) {
			if (ob != null) {
				temp[i] = ob;
				i++;
			}
		}
		obj = temp;
	}

	@Override
	public String toString() {
		return "obj=" + Arrays.toString(obj);
	}

	public static void main(String[] args) {
		Object[] ob = new Object[] { 1, 2, "haha", 4, true, 6, 3042F };
		Collection test2 = new Collection();
		test2.setObj(ob);
		System.err.println(test2.toString());
		test2.insert(8);
		System.err.println(test2.toString());
		test2.remove(4);
		System.err.println(test2.toString());
		test2.remove("haha");
		System.err.println(test2.toString());
	}
}