無法將枚舉數組添加到Collection

Question

此代碼不起作用;

ArrayList<BlockFace> cardinalDirections = new ArrayList<>(); 
    cardinalDirections.addAll(new BlockFace[] {BlockFace.NORTH, BlockFace.SOUTH, BlockFace.EAST, BlockFace.WEST}); 

這也不是;

ArrayList<BlockFace> cardinalDirections = Arrays.asList(new BlockFace[] {BlockFace.NORTH, BlockFace.SOUTH, BlockFace.EAST, BlockFace.WEST}); 

它只工作，如果我手動添加每個元素一次，或迭代通過數組;

ArrayList<BlockFace> cardinalDirections = new ArrayList<>(); 
    for (BlockFace face : new BlockFace[] {BlockFace.NORTH, BlockFace.SOUTH, BlockFace.EAST, BlockFace.WEST}) 
     cardinalDirections.add(face); 

爲什麼前兩個例子不起作用？

Answer 1

您的方法不起作用，因爲ArrayList.addAll需要Collection而不是數組。

轉換枚舉ArrayList的

List<BlockFace> list = Arrays.asList(BlockFace.values());