import java.nio.file.Path;
import java.nio.file.Paths;

public class FilePaths {
    public static void main(String[] args) {
        // Paths.get() should be used to construct paths in a portable way.
        // It takes any number of arguments and constructs a hierarchical path from them.
        Path p = Paths.get("dir1", "dir2", "filename");
        System.out.println("p: " + p);

        // You should always use Paths.get() instead of concatenating
        // / or \ manually. In addition to providing portability,
        // Paths.get() will also normalize paths by removing superfluous
        // separators and directory changes.
        System.out.println(Paths.get("dir1//", "filename"));
        System.out.println(Paths.get("dir1/../dir1", "filename"));

        // getParent() and getFileName() can be used to split a path to the
        // directory and the file.
        System.out.println("p.getParent(): " + p.getParent());
        System.out.println("p.getFileName(): " + p.getFileName());

        // We can check whether a path is absolute.
        System.out.println(Paths.get("dir/file").isAbsolute());
        System.out.println(Paths.get("/dir/file").isAbsolute());

        String filename = "config.json";

        // Some file names have extensions following a dot. We can
        // split the extension out of such names.
        int dotIndex = filename.lastIndexOf('.');
        String ext = (dotIndex == -1) ? "" : filename.substring(dotIndex);
        System.out.println(ext);

        // To find the file's name with the extension removed,
        // use substring.
        System.out.println(filename.substring(0, filename.length() - ext.length()));

        // relativize() finds a relative path between a base and a target.
        // It returns a Path that can be empty if the two paths are the same.
        Path base = Paths.get("a/b");
        Path target = Paths.get("a/b/t/file");
        Path rel = base.relativize(target);
        System.out.println(rel);

        target = Paths.get("a/c/t/file");
        rel = base.relativize(target);
        System.out.println(rel);
    }
}