Java nio。 空路径

Question

Can anyone tell me where Paths.get("") points to?

Here is the code and the output.

public static void main(String[] args) {
    Path path = Paths.get("");
    System.out.printf("`%s`%n", path);
    System.out.printf("`%s`%n", path.normalize());
    System.out.println(Files.exists(path));
    System.out.println(Files.isExecutable(path));
}

``
``
true
true

Answer 1

It maps to the directory from which you run your program. Convert it to an absolute path to test yourself. System.out.println(Paths.get("").toAbsolutePath());

Answer 2

System.out.println(Paths.get("").toAbsolutePath());

/Users/andrew/workspace/scratch

Looks like it's the current working directory. On my machine, Java is reporting that it's executable because the 'x' flag on the directory is true for the current user.

From the javadocs :

This method checks that a file exists and that this Java virtual machine has appropriate privileges to execute the file. The semantics may differ when checking access to a directory. For example, on UNIX systems, checking for execute access checks that the Java virtual machine has permission to search the directory in order to access file or subdirectories.

Answer 3

As documentation says it has link to existing File System:

using it will imply an assumed reference to the default FileSystem and limit the utility of the calling code

You can check with small update:

public static void main(String[] args) {
        Path path = Paths.get("");

        System.out.printf("`%s`%n", path);
        System.out.printf("`%s`%n", path.normalize());
        System.out.println(Files.exists(path));
        System.out.println(Files.isExecutable(path));

        System.out.println(path.toFile().getAbsolutePath());
    }

Last output is something like:

C:\\Users\\Nazar\\Projects\\IdeaProjects\\test-project