public interfacePathextendsComparable<Path>,Iterable<Path>,Watchable
APath represents a path that is hierarchical and composed of a sequence of directory and file name elements separated by a special separator or delimiter. Aroot component, that identifies a file system hierarchy, may also be present. The name element that isfarthest from the root of the directory hierarchy is the name of a file or directory. The other name elements are directory names. APath can represent a root, a root and a sequence of names, or simply one or more name elements. APath is considered to be anempty path if it consists solely of one name element that is empty. Accessing a file using anempty path is equivalent to accessing the default directory of the file system.Path defines thegetFileName,getParent,getRoot, andsubpath methods to access the path components or a subsequence of its name elements.
In addition to accessing the components of a path, aPath also defines theresolve andresolveSibling methods to combine paths. Therelativize method that can be used to construct a relative path between two paths. Paths can becompared, and tested against each other using thestartsWith andendsWith methods.
This interface extendsWatchable interface so that a directory located by a path can beregistered with aWatchService and entries in the directory watched.
WARNING: This interface is only intended to be implemented by those developing custom file system implementations. Methods may be added to this interface in future releases.
Paths may be used with theFiles class to operate on files, directories, and other types of files. For example, suppose we want aBufferedReader to read text from a file "access.log". The file is located in a directory "logs" relative to the current working directory and is UTF-8 encoded.
Path path = FileSystems.getDefault().getPath("logs", "access.log"); BufferedReader reader = Files.newBufferedReader(path, StandardCharsets.UTF_8); Paths associated with the defaultprovider are generally interoperable with thejava.io.File class. Paths created by other providers are unlikely to be interoperable with the abstract path names represented byjava.io.File. ThetoPath method may be used to obtain aPath from the abstract path name represented by ajava.io.File object. The resultingPath can be used to operate on the same file as thejava.io.File object. In addition, thetoFile method is useful to construct aFile from theString representation of aPath.
Implementations of this interface are immutable and safe for use by multiple concurrent threads.
Paths| Modifier and Type | Method | Description |
|---|---|---|
int | compareTo(Path other) | Compares two abstract paths lexicographically. |
boolean | endsWith(Path other) | Tests if this path ends with the given path. |
boolean | endsWith(String other) | Tests if this path ends with a Path, constructed by converting the given path string, in exactly the manner specified by theendsWith(Path) method. |
boolean | equals(Object other) | Tests this path for equality with the given object. |
Path | getFileName() | Returns the name of the file or directory denoted by this path as a Path object. |
FileSystem | getFileSystem() | Returns the file system that created this object. |
Path | getName(int index) | Returns a name element of this path as a Path object. |
int | getNameCount() | Returns the number of name elements in the path. |
Path | getParent() | Returns theparent path, or null if this path does not have a parent. |
Path | getRoot() | Returns the root component of this path as a Path object, ornull if this path does not have a root component. |
int | hashCode() | Computes a hash code for this path. |
boolean | isAbsolute() | Tells whether or not this path is absolute. |
Iterator<Path> | iterator() | Returns an iterator over the name elements of this path. |
Path | normalize() | Returns a path that is this path with redundant name elements eliminated. |
WatchKey | register(WatchService watcher,WatchEvent.Kind<?>... events) | Registers the file located by this path with a watch service. |
WatchKey | register(WatchService watcher,WatchEvent.Kind<?>[] events,WatchEvent.Modifier... modifiers) | Registers the file located by this path with a watch service. |
Path | relativize(Path other) | Constructs a relative path between this path and a given path. |
Path | resolve(Path other) | Resolve the given path against this path. |
Path | resolve(String other) | Converts a given path string to a Path and resolves it against thisPath in exactly the manner specified by theresolve method. |
Path | resolveSibling(Path other) | Resolves the given path against this path's parent path. |
Path | resolveSibling(String other) | Converts a given path string to a Path and resolves it against this path'sparent path in exactly the manner specified by theresolveSibling method. |
boolean | startsWith(Path other) | Tests if this path starts with the given path. |
boolean | startsWith(String other) | Tests if this path starts with a Path, constructed by converting the given path string, in exactly the manner specified by thestartsWith(Path) method. |
Path | subpath(int beginIndex, int endIndex) | Returns a relative Path that is a subsequence of the name elements of this path. |
Path | toAbsolutePath() | Returns a Path object representing the absolute path of this path. |
File | toFile() | Returns a File object representing this path. |
Path | toRealPath(LinkOption... options) | Returns thereal path of an existing file. |
String | toString() | Returns the string representation of this path. |
URI | toUri() | Returns a URI to represent this path. |
forEach,spliteratorFileSystem getFileSystem()
boolean isAbsolute()
An absolute path is complete in that it doesn't need to be combined with other path information in order to locate a file.
true if, and only if, this path is absolutePath getRoot()
Path object, ornull if this path does not have a root component.nullPath getFileName()
Path object. The file name is thefarthest element from the root in the directory hierarchy.null if this path has zero elementsPath getParent()
null if this path does not have a parent. The parent of this path object consists of this path's root component, if any, and each element in the path except for thefarthest from the root in the directory hierarchy. This method does not access the file system; the path or its parent may not exist. Furthermore, this method does not eliminate special names such as "." and ".." that may be used in some implementations. On UNIX for example, the parent of "/a/b/c" is "/a/b", and the parent of"x/y/." is "x/y". This method may be used with thenormalize method, to eliminate redundant names, for cases whereshell-like navigation is required.
If this path has one or more elements, and no root component, then this method is equivalent to evaluating the expression:
subpath(0, getNameCount()-1);
int getNameCount()
0 if this path only represents a root componentPath getName(int index)
Path object. Theindex parameter is the index of the name element to return. The element that isclosest to the root in the directory hierarchy has index0. The element that isfarthest from the root has indexcount-1.
index - the index of the elementIllegalArgumentException - ifindex is negative,index is greater than or equal to the number of elements, or this path has zero name elementsPath subpath(int beginIndex, int endIndex)
Path that is a subsequence of the name elements of this path. ThebeginIndex andendIndex parameters specify the subsequence of name elements. The name that isclosest to the root in the directory hierarchy has index0. The name that isfarthest from the root has indexcount-1. The returnedPath object has the name elements that begin atbeginIndex and extend to the element at indexendIndex-1.
beginIndex - the index of the first element, inclusiveendIndex - the index of the last element, exclusivePath object that is a subsequence of the name elements in thisPathIllegalArgumentException - ifbeginIndex is negative, or greater than or equal to the number of elements. IfendIndex is less than or equal tobeginIndex, or larger than the number of elements.boolean startsWith(Path other)
This pathstarts with the given path if this path's root componentstarts with the root component of the given path, and this path starts with the same name elements as the given path. If the given path has more name elements than this path thenfalse is returned.
Whether or not the root component of this path starts with the root component of the given path is file system specific. If this path does not have a root component and the given path has a root component then this path does not start with the given path.
If the given path is associated with a differentFileSystem to this path thenfalse is returned.
other - the given pathtrue if this path starts with the given path; otherwisefalseboolean startsWith(String other)
Path, constructed by converting the given path string, in exactly the manner specified by thestartsWith(Path) method. On UNIX for example, the path "foo/bar" starts with "foo" and "foo/bar". It does not start with "f" or "fo".other - the given path stringtrue if this path starts with the given path; otherwisefalseInvalidPathException - If the path string cannot be converted to a Path.boolean endsWith(Path other)
If the given path hasN elements, and no root component, and this path hasN or more elements, then this path ends with the given path if the lastN elements of each path, starting at the element farthest from the root, are equal.
If the given path has a root component then this path ends with the given path if the root component of this pathends with the root component of the given path, and the corresponding elements of both paths are equal. Whether or not the root component of this path ends with the root component of the given path is file system specific. If this path does not have a root component and the given path has a root component then this path does not end with the given path.
If the given path is associated with a differentFileSystem to this path thenfalse is returned.
other - the given pathtrue if this path ends with the given path; otherwisefalseboolean endsWith(String other)
Path, constructed by converting the given path string, in exactly the manner specified by theendsWith(Path) method. On UNIX for example, the path "foo/bar" ends with "foo/bar" and "bar". It does not end with "r" or "/bar". Note that trailing separators are not taken into account, and so invoking this method on thePath"foo/bar" with theString "bar/" returnstrue.other - the given path stringtrue if this path ends with the given path; otherwisefalseInvalidPathException - If the path string cannot be converted to a Path.Path normalize()
The precise definition of this method is implementation dependent but in general it derives from this path, a path that does not containredundant name elements. In many file systems, the "." and ".." are special names used to indicate the current directory and parent directory. In such file systems all occurrences of "." are considered redundant. If a ".." is preceded by a non-".." name then both names are considered redundant (the process to identify such names is repeated until it is no longer applicable).
This method does not access the file system; the path may not locate a file that exists. Eliminating ".." and a preceding name from a path may result in the path that locates a different file than the original path. This can arise when the preceding name is a symbolic link.
getParent(),toRealPath(java.nio.file.LinkOption...)Path resolve(Path other)
If theother parameter is anabsolute path then this method trivially returnsother. Ifother is anempty path then this method trivially returns this path. Otherwise this method considers this path to be a directory and resolves the given path against this path. In the simplest case, the given path does not have aroot component, in which case this methodjoins the given path to this path and returns a resulting path thatends with the given path. Where the given path has a root component then resolution is highly implementation dependent and therefore unspecified.
other - the path to resolve against this pathrelativize(java.nio.file.Path)Path resolve(String other)
Path and resolves it against thisPath in exactly the manner specified by theresolve method. For example, suppose that the name separator is "/" and a path represents "foo/bar", then invoking this method with the path string "gus" will result in thePath "foo/bar/gus".other - the path string to resolve against this pathInvalidPathException - if the path string cannot be converted to a Path.FileSystem.getPath(java.lang.String, java.lang.String...)Path resolveSibling(Path other)
parent path. This is useful where a file name needs to bereplaced with another file name. For example, suppose that the name separator is "/" and a path represents "dir1/dir2/foo", then invoking this method with thePath "bar" will result in thePath "dir1/dir2/bar". If this path does not have a parent path, orother isabsolute, then this method returnsother. Ifother is an empty path then this method returns this path's parent, or where this path doesn't have a parent, the empty path.other - the path to resolve against this path's parentresolve(Path)Path resolveSibling(String other)
Path and resolves it against this path'sparent path in exactly the manner specified by theresolveSibling method.other - the path string to resolve against this path's parentInvalidPathException - if the path string cannot be converted to a Path.FileSystem.getPath(java.lang.String, java.lang.String...)Path relativize(Path other)
Relativization is the inverse ofresolution. This method attempts to construct arelative path that whenresolved against this path, yields a path that locates the same file as the given path. For example, on UNIX, if this path is"/a/b" and the given path is"/a/b/c/d" then the resulting relative path would be"c/d". Where this path and the given path do not have aroot component, then a relative path can be constructed. A relative path cannot be constructed if only one of the paths have a root component. Where both paths have a root component then it is implementation dependent if a relative path can be constructed. If this path and the given path areequal then anempty path is returned.
For any twonormalized pathsp andq, whereq does not have a root component,
p.relativize(p.resolve(q)).equals(q)
When symbolic links are supported, then whether the resulting path, when resolved against this path, yields a path that can be used to locate thesame file asother is implementation dependent. For example, if this path is"/a/b" and the given path is"/a/x" then the resulting relative path may be"../x". If"b" is a symbolic link then is implementation dependent if"a/b/../x" would locate the same file as"/a/x".
other - the path to relativize against this pathIllegalArgumentException - ifother is not aPath that can be relativized against this pathURI toUri()
This method constructs an absoluteURI with ascheme equal to the URI scheme that identifies the provider. The exact form of the scheme specific part is highly provider dependent.
In the case of the default provider, the URI is hierarchical with apath component that is absolute. The query and fragment components are undefined. Whether the authority component is defined or not is implementation dependent. There is no guarantee that theURI may be used to construct ajava.io.File. In particular, if this path represents a Universal Naming Convention (UNC) path, then the UNC server name may be encoded in the authority component of the resulting URI. In the case of the default provider, and the file exists, and it can be determined that the file is a directory, then the resultingURI will end with a slash.
The default provider provides a similarround-trip guarantee to theFile class. For a givenPathp it is guaranteed that
so long as the originalPaths.get(p.toUri()).equals(p.toAbsolutePath())
Path, theURI, and the newPath are all created in (possibly different invocations of) the same Java virtual machine. Whether other providers make any guarantees is provider specific and therefore unspecified.When a file system is constructed to access the contents of a file as a file system then it is highly implementation specific if the returned URI represents the given path in the file system or it represents acompound URI that encodes the URI of the enclosing file system. A format for compound URIs is not defined in this release; such a scheme may be added in a future release.
IOError - if an I/O error occurs obtaining the absolute path, or where a file system is constructed to access the contents of a file as a file system, and the URI of the enclosing file system cannot be obtainedSecurityException - In the case of the default provider, and a security manager is installed, thetoAbsolutePath method throws a security exception.Path toAbsolutePath()
Path object representing the absolute path of this path. If this path is alreadyabsolute then this method simply returns this path. Otherwise, this method resolves the path in an implementation dependent manner, typically by resolving the path against a file system default directory. Depending on the implementation, this method may throw an I/O error if the file system is not accessible.
Path object representing the absolute pathIOError - if an I/O error occursSecurityException - In the case of the default provider, a security manager is installed, and this path is not absolute, then the security manager'scheckPropertyAccess method is invoked to check access to the system propertyuser.dirPath toRealPath(LinkOption... options) throwsIOException
The precise definition of this method is implementation dependent but in general it derives from this path, anabsolute path that locates thesame file as this path, but with name elements that represent the actual name of the directories and the file. For example, where filename comparisons on a file system are case insensitive then the name elements represent the names in their actual case. Additionally, the resulting path has redundant name elements removed.
If this path is relative then its absolute path is first obtained, as if by invoking thetoAbsolutePath method.
Theoptions array may be used to indicate how symbolic links are handled. By default, symbolic links are resolved to their final target. If the optionNOFOLLOW_LINKS is present then this method does not resolve symbolic links. Some implementations allow special names such as ".." to refer to the parent directory. When deriving thereal path, and a ".." (or equivalent) is preceded by a non-".." name then an implementation will typically cause both names to be removed. When not resolving symbolic links and the preceding name is a symbolic link then the names are only removed if it guaranteed that the resulting path will locate the same file as this path.
options - options indicating how symbolic links are handledIOException - if the file does not exist or an I/O error occursSecurityException - In the case of the default provider, and a security manager is installed, itscheckRead method is invoked to check read access to the file, and where this path is not absolute, itscheckPropertyAccess method is invoked to check access to the system propertyuser.dirFile toFile()
File object representing this path. Where thisPath is associated with the default provider, then this method is equivalent to returning aFile object constructed with theString representation of this path. If this path was created by invoking theFiletoPath method then there is no guarantee that theFile object returned by this method isequal to the originalFile.
File object representing this pathUnsupportedOperationException - if thisPath is not associated with the default providerWatchKey register(WatchService watcher,WatchEvent.Kind<?>[] events,WatchEvent.Modifier... modifiers) throwsIOException
In this release, this path locates a directory that exists. The directory is registered with the watch service so that entries in the directory can be watched. Theevents parameter is the events to register and may contain the following events:
ENTRY_CREATE - entry created or moved into the directoryENTRY_DELETE - entry deleted or moved out of the directoryENTRY_MODIFY - entry in directory was modified Thecontext for these events is the relative path between the directory located by this path, and the path that locates the directory entry that is created, deleted, or modified.
The set of events may include additional implementation specific event that are not defined by the enumStandardWatchEventKinds
Themodifiers parameter specifiesmodifiers that qualify how the directory is registered. This release does not define anystandard modifiers. It may contain implementation specific modifiers.
Where a file is registered with a watch service by means of a symbolic link then it is implementation specific if the watch continues to depend on the existence of the symbolic link after it is registered.
register in interface Watchablewatcher - the watch service to which this object is to be registeredevents - the events for which this object should be registeredmodifiers - the modifiers, if any, that modify how the object is registeredUnsupportedOperationException - if unsupported events or modifiers are specifiedIllegalArgumentException - if an invalid combination of events or modifiers is specifiedClosedWatchServiceException - if the watch service is closedNotDirectoryException - if the file is registered to watch the entries in a directory and the file is not a directory(optional specific exception)IOException - if an I/O error occursSecurityException - In the case of the default provider, and a security manager is installed, thecheckRead method is invoked to check read access to the file.WatchKey register(WatchService watcher,WatchEvent.Kind<?>... events) throwsIOException
An invocation of this method behaves in exactly the same way as the invocation
watchable.register(watcher, events, new WatchEvent.Modifier[0]);Usage Example: Suppose we wish to register a directory for entry create, delete, and modify events:
Path dir = ... WatchService watcher = ... WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);
register in interface Watchablewatcher - The watch service to which this object is to be registeredevents - The events for which this object should be registeredUnsupportedOperationException - If unsupported events are specifiedIllegalArgumentException - If an invalid combination of events is specifiedClosedWatchServiceException - If the watch service is closedNotDirectoryException - If the file is registered to watch the entries in a directory and the file is not a directory(optional specific exception)IOException - If an I/O error occursSecurityException - In the case of the default provider, and a security manager is installed, thecheckRead method is invoked to check read access to the file.Iterator<Path> iterator()
The first element returned by the iterator represents the name element that is closest to the root in the directory hierarchy, the second element is the next closest, and so on. The last element returned is the name of the file or directory denoted by this path. Theroot component, if present, is not returned by the iterator.
int compareTo(Path other)
This method may not be used to compare paths that are associated with different file system providers.
compareTo in interface Comparable<Path>other - the path compared to this path.equal to this path, a value less than zero if this path is lexicographically less than the argument, or a value greater than zero if this path is lexicographically greater than the argumentClassCastException - if the paths are associated with different providersboolean equals(Object other)
If the given object is not a Path, or is a Path associated with a differentFileSystem, then this method returnsfalse.
Whether or not two path are equal depends on the file system implementation. In some cases the paths are compared without regard to case, and others are case sensitive. This method does not access the file system and the file is not required to exist. Where required, theisSameFile method may be used to check if two paths locate the same file.
This method satisfies the general contract of theObject.equals method.
equals in class Objectother - the object to which this object is to be comparedtrue if, and only if, the given object is aPath that is identical to thisPathObject.hashCode(),HashMapint hashCode()
The hash code is based upon the components of the path, and satisfies the general contract of theObject.hashCode method.
hashCode in class ObjectObject.equals(java.lang.Object),System.identityHashCode(java.lang.Object)String toString()
If this path was created by converting a path string using thegetPath method then the path string returned by this method may differ from the original String used to create the path.
The returned path string uses the default nameseparator to separate names in the path.