Java Reference
In-Depth Information
Creating a Path Object
A
FileSystem
object acts as a factory to create a
Path
object. You can use the
getPath()
method of the
FileSystem
class to create a
Path
object. The following snippet of code creates a
Path
object for file path
C:\poems\luci1.txt
on
Windows:
Path p1 = FileSystems.getDefault().getPath("C:\\poems\\luci1.txt");
You can pass components of a path separately to the
getPath()
method when constructing a
Path
object. Java
will take care of using an appropriate platform-dependent file name separators. The following statement creates a
Path
object to represent the
C:\poems\luci1.txt
path on Windows:
Path p2 = FileSystems.getDefault().getPath("C:", "poems", "luci1.txt");
The
Path
API includes a utility class called
Paths
whose sole job is to create a
Path
object from the components
of a path string or a
URI
. The
Paths.get()
static method creates a
Path
object. Internally, it delegates the call to the
default
FileSystem
object. The following snippet of code creates
Path
objects to represent the same path,
C:\poems\luci1.txt
:
Path p3 = Paths.get("C:\\poems\\luci1.txt");
Path p4 = Paths.get("C:", "poems", "luci1.txt");
■
You can create a
Path
object from an empty path such as
Paths.get("")
. a
Path
object with an empty path
refers to the default directory of the file system. a default directory is the same as the current working directory.
Tip
Accessing Components of a Path
A path in a file system consists of one or more components. The methods of the
Path
interface let you access those
components.
The
getNameCount()
method returns the number of components in a
Path
object excluding the root. For
example, the path
C:\poems\luci1.txt
consists of three components: a root of
C:
, and two components named
poems
and
luci1.txt
. In this case, the
getNameCount()
method will return 2. The
getName(int index)
method returns the
component name at the specified
index
. The component that is closest to the root has an index of 0. The component
that is farthest from the root has an index of
count - 1
. In the path
C:\poems\luci1.txt
, the
poems
component has
an index of 0 and the
luci1.txt
component has an index of 1.
The
getParent()
method returns the parent of a path. If a path does not have a parent, it returns
null
. The
parent of a path is the path itself without the farthest component from the root. For example, the parent of the path
C:\poems\luci.txt
is
C:\poems
. The relative path
test.txt
has no parent.
The
getRoot()
method returns the root of the path. If a path does not have a root, it returns
null
. For example,
the path
C:\poems\luci1.txt
on Windows has
C:\
as its root.
The
getFileName()
method returns the file name denoted by the path. If a path has no file name, it returns
null
.
The file name is the farthest component from the root. For example, in the path
C:\poems\luci1.txt
,
luci1.txt
is
the file name.
You can check if a path represents an absolute path by using the
isAbsolute()
method. Note that a path does not
have to exist in the file system to get information about its components. The
Path
API uses the information provided
in the path string to give you all these pieces of information.
