A Path represents a path that is hierarchical and composed of a sequence of directory and file name elements separated by a special separator or delimiter. A root component, that identifies a file system hierarchy, may also be present. The name element that is farthest from the root of the directory hierarchy is the name of a file or directory. The other name elements are directory names. A Path can represent a root, a root and a sequence of names, or simply one or more name elements. A Path is considered to be an empty path if it consists solely of one name element that is empty. Accessing a file using an empty path is equivalent to accessing the default directory of the file system. Path defines the getFileName, getParent, getRoot, and subpath methods to access the path components or a subsequence of its name elements.
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In addition to accessing the components of a path, a Path also defines the resolve and resolveSibling methods to combine paths. The relativize method that can be used to construct a relative path between two paths. Paths can be compared, and tested against each other using the startsWith and endsWith methods.
Paths may be used with the Files class to operate on files, directories, and other types of files. For example, suppose we want a BufferedReader 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 default provider are generally interoperable with the java.io.File class. Paths created by other providers are unlikely to be interoperable with the abstract path names represented by java.io.File. The toPath method may be used to obtain a Path from the abstract path name represented by a java.io.File object. The resulting Path can be used to operate on the same file as the java.io.File object. In addition, the toFile method is useful to construct a File from the String representation of a Path.
Note that while this method is very convenient, using it will imply an assumed reference to the default FileSystem and limit the utility of the calling code. Hence it should not be used in library code intended for flexible reuse. A more flexible alternative is to use an existing Path instance as an anchor, such as: Path dir = ... Path path = dir.resolve("file");
In the case of the default provider, identified by the URI scheme "file", the given URI has a non-empty path component, and undefined query and fragment components. Whether the authority component may be present is platform specific. The returned Path is associated with the default file system.
The parent of this path object consists of this path's root component, if any, and each element in the path except for the farthest 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 the normalize method, to eliminate redundant names, for cases where shell-like navigation is required.
This path starts with the given path if this path's root component starts 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 then false 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 has N elements, and no root component, and this path has N or more elements, then this path ends with the given path if the last N 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 path ends 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.
The precise definition of this method is implementation dependent but in general it derives from this path, a path that does not contain redundant 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.
If the other parameter is an absolute path then this method trivially returns other. If other is an empty 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 a root component, in which case this method joins the given path to this path and returns a resulting path that ends with the given path. Where the given path has a root component then resolution is highly implementation dependent and therefore unspecified.
Relativization is the inverse of resolution. This method attempts to construct a relative path that when resolved 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 a root 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 are equal then an empty path is returned.
When symbolic links are supported, then whether the resulting path, when resolved against this path, yields a path that can be used to locate the same file as other 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".
In the case of the default provider, the URI is hierarchical with a path 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 the URI may be used to construct a java.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 resulting URI will end with a slash.
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 a compound 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.
If this path is already absolute 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.
The precise definition of this method is implementation dependent but in general it derives from this path, an absolute path that locates the same 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.
The options array may be used to indicate how symbolic links are handled. By default, symbolic links are resolved to their final target. If the option NOFOLLOW_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 the real 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.
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. The events parameter is the events to register and may contain the following events: ENTRY_CREATE - entry created or moved into the directory
ENTRY_DELETE - entry deleted or moved out of the directory
ENTRY_MODIFY - entry in directory was modified
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