首先，检查您使用的Java版本是否正确？
由于Java 9才支持List接口的static工厂方法，请参见List.of。
private static List<Item> defaultItems() {
//java 8
return Arrays.asList(
new Item(1L, "Burger", 599L, "Tasty", "https://cdn.auth0.com/blog/whatabyte/burger-sm.png"),
new Item(2L, "Pizza", 299L, "Cheesy", "https://cdn.auth0.com/blog/whatabyte/pizza-sm.png"),
new Item(3L, "Tea", 199L, "Informative", "https://cdn.auth0.com/blog/whatabyte/tea-sm.png")
);
// //java 11
// return List.of(
// new Item(1L, "Burger", 599L, "Tasty", "https://cdn.auth0.com/blog/whatabyte/burger-sm.png"),
// new Item(2L, "Pizza", 299L, "Cheesy", "https://cdn.auth0.com/blog/whatabyte/pizza-sm.png"),
// new Item(3L, "Tea", 199L, "Informative", "https://cdn.auth0.com/blog/whatabyte/tea-sm.png")
// );
}
java-8-how-to-initialize-list-of-list-in-one-line
