java - Files.createDirectory的返回值有什么用

Question

Files.createDirectory的签名是

public static Path createDirectory(Path dir, FileAttribute<?>... attrs) IOException

文档是这么说的

Parameters:

• dir - the directory to create
• attrs - an optional list of file attributes to set atomically when creating the directory

Returns:

• the directory

这只是为了允许方法链接，还是还有更多的内容？例如，在这段代码中

Path directory = Paths.get("./results");
Path created = Path.createDirectory(directory);

我们应该使用目录还是创建？

我检查了 OpenJDK 的源代码它返回参数，但它是由标准保证的吗？

Answer 1

据Java 8 OCP Guide (第 462 页)，方法链接是此策略的目的:

Many of the methods in the Path interface transform the path value in some way and return a new Path object, allowing the methods to be chained.