这句代码没有意义吗？为何提示我：Null pointer access？

[whlweb]

	public static void novelcatalogview() throws IOException {
		ArrayList<Novel> novellist = null;
		ArrayList<Novel> novellist2 = null;
		String category = null;
		System.out.println("----------------------------------");
		System.out.println("0.返回上一级菜单");
		System.out.println("1.武侠");
		System.out.println("2.言情");
		System.out.println("----------------------------------");
		System.out.print("请选择：");
		int choice = input.nextInt();
		if (choice == 0) {
			return;
		} else if (choice == 1) {
			category = "武侠";
		} else if (choice == 2) {
			category = "言情";
		} else {
			System.out.println("输入错误，请重新选择！");
			novelcatalogview();
		}
		System.out.println("----------------" + category
				+ "小说列表----------------");
		System.out.println("序号" + "\t" + "名称" + "\t" + "简介");

			novellist = cb.getNovelList();
			for (Novel novel : novellist) {
				if (novel.getCategory().equals("category")) {



				novellist2.add(novel);

//为何上一句提示我 “Null pointer access: The variable novellist2 can only be null at this location”
//novellist2 写在这里只能是 null吗?这句代码没有意义？


				}
				 for (int i=0;i<novellist2.size();i++) {
				 System.out.println(i+1 + "\t" + novel.getName() + "\t"
				 + novel.getDescription());
				 }
			}
		
		System.out.println("----------------小说列表结束----------------");
		System.out.println("阅读和下载请输入文件序号，上传请输入-1，返回请输入0：");
		int choice2 = input.nextInt();
		if (choice2 == 0) {
			return;
		} else if (choice2 != -1) {

		}

	}

}

[小小X]

ArrayList<Novel> novellist2 = new ArrayList<Novel>();

[whlweb]

[Quote=引用 1 楼 yangjunloveyu 的回复:]
ArrayList<Novel> novellist2 = new ArrayList<Novel>();
[/Quote]
多谢多谢！
要不然我就掉坑里了 哈哈