/**@class java.nio.file.FileSystem implements java.io.Closeable @extends java.lang.Object Provides an interface to a file system and is the factory for objects to access files and other objects in the file system. <p> The default file system, obtained by invoking the {@link java.nio.file.FileSystems#getDefault java.nio.file.FileSystems.getDefault} method, provides access to the file system that is accessible to the Java virtual machine. The {@link java.nio.file.FileSystems} class defines methods to create file systems that provide access to other types of (custom) file systems. <p> A file system is the factory for several types of objects: <ul> <li><p> The {@link #getPath getPath} method converts a system dependent <em>path string</em>, returning a {@link java.nio.file.Path} object that may be used to locate and access a file. </p></li> <li><p> The {@link #getPathMatcher getPathMatcher} method is used to create a {@link java.nio.file.PathMatcher} that performs match operations on paths. </p></li> <li><p> The {@link #getFileStores getFileStores} method returns an iterator over the underlying {@link java.nio.file.FileStore file-stores}. </p></li> <li><p> The {@link #getUserPrincipalLookupService getUserPrincipalLookupService} method returns the {@link UserPrincipalLookupService} to lookup users or groups by name. </p></li> <li><p> The {@link #newWatchService newWatchService} method creates a {@link java.nio.file.WatchService} that may be used to watch objects for changes and events. </p></li> </ul> <p> File systems vary greatly. In some cases the file system is a single hierarchy of files with one top-level root directory. In other cases it may have several distinct file hierarchies, each with its own top-level root directory. The {@link #getRootDirectories getRootDirectories} method may be used to iterate over the root directories in the file system. A file system is typically composed of one or more underlying {@link java.nio.file.FileStore file-stores} that provide the storage for the files. Theses file stores can also vary in the features they support, and the file attributes or <em>meta-data</em> that they associate with files. <p> A file system is open upon creation and can be closed by invoking its {@link #close() close} method. Once closed, any further attempt to access objects in the file system cause {@link java.nio.file.ClosedFileSystemException} to be thrown. File systems created by the default {@link java.nio.file.FileSystemProvider provider} cannot be closed. <p> A {@code FileSystem} can provide read-only or read-write access to the file system. Whether or not a file system provides read-only access is established when the {@code FileSystem} is created and can be tested by invoking its {@link #isReadOnly() isReadOnly} method. Attempts to write to file stores by means of an object associated with a read-only file system throws {@link java.nio.file.ReadOnlyFileSystemException}. <p> File systems are safe for use by multiple concurrent threads. The {@link #close close} method may be invoked at any time to close a file system but whether a file system is <i>asynchronously closeable</i> is provider specific and therefore unspecified. In other words, if a thread is accessing an object in a file system, and another thread invokes the {@code close} method then it may require to block until the first operation is complete. Closing a file system causes all open channels, watch services, and other {@link Closeable closeable} objects associated with the file system to be closed. @since 1.7 */ var FileSystem = { /**Returns the provider that created this file system. @return {Object {java.nio.file.spi.FileSystemProvider}} The provider that created this file system. */ provider : function( ) {}, /**Closes this file system. <p> After a file system is closed then all subsequent access to the file system, either by methods defined by this class or on objects associated with this file system, throw {@link java.nio.file.ClosedFileSystemException}. If the file system is already closed then invoking this method has no effect. <p> Closing a file system will close all open {@link java.nio.channels.Channel channels}, {@link java.nio.file.DirectoryStream directory-streams}, {@link java.nio.file.WatchService watch-service}, and other closeable objects associated with this file system. The {@link java.nio.file.FileSystems#getDefault default} file system cannot be closed. @throws IOException If an I/O error occurs @throws UnsupportedOperationException Thrown in the case of the default file system */ close : function( ) {}, /**Tells whether or not this file system is open. <p> File systems created by the default provider are always open. @return {Boolean} {@code true} if, and only if, this file system is open */ isOpen : function( ) {}, /**Tells whether or not this file system allows only read-only access to its file stores. @return {Boolean} {@code true} if, and only if, this file system provides read-only access */ isReadOnly : function( ) {}, /**Returns the name separator, represented as a string. <p> The name separator is used to separate names in a path string. An implementation may support multiple name separators in which case this method returns an implementation specific <em>default</em> name separator. This separator is used when creating path strings by invoking the {@link java.nio.file.Path#toString() toString()} method. <p> In the case of the default provider, this method returns the same separator as {@link java.io.File#separator}. @return {String} The name separator */ getSeparator : function( ) {}, /**Returns an object to iterate over the paths of the root directories. <p> A file system provides access to a file store that may be composed of a number of distinct file hierarchies, each with its own top-level root directory. Unless denied by the security manager, each element in the returned iterator corresponds to the root directory of a distinct file hierarchy. The order of the elements is not defined. The file hierarchies may change during the lifetime of the Java virtual machine. For example, in some implementations, the insertion of removable media may result in the creation of a new file hierarchy with its own top-level directory. <p> When a security manager is installed, it is invoked to check access to the each root directory. If denied, the root directory is not returned by the iterator. In the case of the default provider, the {@link SecurityManager#checkRead(String)} method is invoked to check read access to each root directory. It is system dependent if the permission checks are done when the iterator is obtained or during iteration. @return {Object {java.lang.Iterable}} An object to iterate over the root directories */ getRootDirectories : function( ) {}, /**Returns an object to iterate over the underlying file stores. <p> The elements of the returned iterator are the {@link java.nio.file.FileStore java.nio.file.FileStores} for this file system. The order of the elements is not defined and the file stores may change during the lifetime of the Java virtual machine. When an I/O error occurs, perhaps because a file store is not accessible, then it is not returned by the iterator. <p> In the case of the default provider, and a security manager is installed, the security manager is invoked to check {@link RuntimePermission}<tt>("getFileStoreAttributes")</tt>. If denied, then no file stores are returned by the iterator. In addition, the security manager's {@link SecurityManager#checkRead(String)} method is invoked to check read access to the file store's <em>top-most</em> directory. If denied, the file store is not returned by the iterator. It is system dependent if the permission checks are done when the iterator is obtained or during iteration. <p> <b>Usage Example:</b> Suppose we want to print the space usage for all file stores: <pre> for (FileStore store: FileSystems.getDefault().getFileStores()) { long total = store.getTotalSpace() / 1024; long used = (store.getTotalSpace() - store.getUnallocatedSpace()) / 1024; long avail = store.getUsableSpace() / 1024; System.out.format("%-20s %12d %12d %12d%n", store, total, used, avail); } </pre> @return {Object {java.lang.Iterable}} An object to iterate over the backing file stores */ getFileStores : function( ) {}, /**Returns the set of the {@link FileAttributeView#name names} of the file attribute views supported by this {@code FileSystem}. <p> The {@link BasicFileAttributeView} is required to be supported and therefore the set contains at least one element, "basic". <p> The {@link java.nio.file.FileStore#supportsFileAttributeView(String) supportsFileAttributeView(String)} method may be used to test if an underlying {@link java.nio.file.FileStore} supports the file attributes identified by a file attribute view. @return {Object {java.util.Set}} An unmodifiable set of the names of the supported file attribute views */ supportedFileAttributeViews : function( ) {}, /**Converts a path string, or a sequence of strings that when joined form a path string, to a {@code Path}. If {@code more} does not specify any elements then the value of the {@code first} parameter is the path string to convert. If {@code more} specifies one or more elements then each non-empty string, including {@code first}, is considered to be a sequence of name elements (see {@link java.nio.file.Path}) and is joined to form a path string. The details as to how the Strings are joined is provider specific but typically they will be joined using the {@link #getSeparator name-separator} as the separator. For example, if the name separator is "{@code /}" and {@code getPath("/foo","bar","gus")} is invoked, then the path string {@code "/foo/bar/gus"} is converted to a {@code Path}. A {@code Path} representing an empty path is returned if {@code first} is the empty string and {@code more} does not contain any non-empty strings. <p> The parsing and conversion to a path object is inherently implementation dependent. In the simplest case, the path string is rejected, and {@link java.nio.file.InvalidPathException} thrown, if the path string contains characters that cannot be converted to characters that are <em>legal</em> to the file store. For example, on UNIX systems, the NUL (\u0000) character is not allowed to be present in a path. An implementation may choose to reject path strings that contain names that are longer than those allowed by any file store, and where an implementation supports a complex path syntax, it may choose to reject path strings that are <em>badly formed</em>. <p> In the case of the default provider, path strings are parsed based on the definition of paths at the platform or virtual file system level. For example, an operating system may not allow specific characters to be present in a file name, but a specific underlying file store may impose different or additional restrictions on the set of legal characters. <p> This method throws {@link java.nio.file.InvalidPathException} when the path string cannot be converted to a path. Where possible, and where applicable, the exception is created with an {@link java.nio.file.InvalidPathException#getIndex index} value indicating the first position in the {@code path} parameter that caused the path string to be rejected. @param {String} first the path string or initial part of the path string @param {Object {java.lang.String[]}} more additional strings to be joined to form the path string @return {Object {java.nio.file.Path}} the resulting {@code Path} @throws InvalidPathException If the path string cannot be converted */ getPath : function( ) {}, /**Returns a {@code PathMatcher} that performs match operations on the {@code String} representation of {@link java.nio.file.Path} objects by interpreting a given pattern. The {@code syntaxAndPattern} parameter identifies the syntax and the pattern and takes the form: <blockquote><pre> <i>syntax</i><b>:</b><i>pattern</i> </pre></blockquote> where {@code ':'} stands for itself. <p> A {@code FileSystem} implementation supports the "{@code glob}" and "{@code regex}" syntaxes, and may support others. The value of the syntax component is compared without regard to case. <p> When the syntax is "{@code glob}" then the {@code String} representation of the path is matched using a limited pattern language that resembles regular expressions but with a simpler syntax. For example: <blockquote> <table border="0" summary="Pattern Language"> <tr> <td>{@code *.java}</td> <td>Matches a path that represents a file name ending in {@code .java}</td> </tr> <tr> <td>{@code *.*}</td> <td>Matches file names containing a dot</td> </tr> <tr> <td>{@code *.{java,class}}</td> <td>Matches file names ending with {@code .java} or {@code .class}</td> </tr> <tr> <td>{@code foo.?}</td> <td>Matches file names starting with {@code foo.} and a single character extension</td> </tr> <tr> <td><tt>/home/*/*</tt> <td>Matches <tt>/home/gus/data</tt></td> </tr> <tr> <td><tt>/home/**</tt> <td>Matches <tt>/home/gus</tt> and <tt>/home/gus/data</tt></td> </tr> </table> </blockquote> <p> The following rules are used to interpret glob patterns: <ul> <li><p> The {@code *} character matches zero or more {@link Character characters} of a {@link java.nio.file.Path#getName(int) name} component without crossing directory boundaries. </p></li> <li><p> The {@code **} characters matches zero or more {@link Character characters} crossing directory boundaries. </p></li> <li><p> The {@code ?} character matches exactly one character of a name component.</p></li> <li><p> The backslash character ({@code \}) is used to escape characters that would otherwise be interpreted as special characters. The expression {@code \\} matches a single backslash and "\{" matches a left brace for example. </p></li> <li><p> The {@code [ ]} characters are a <i>bracket expression</i> that match a single character of a name component out of a set of characters. For example, {@code [abc]} matches {@code "a"}, {@code "b"}, or {@code "c"}. The hyphen ({@code -}) may be used to specify a range so {@code [a-z]} specifies a range that matches from {@code "a"} to {@code "z"} (inclusive). These forms can be mixed so [abce-g] matches {@code "a"}, {@code "b"}, {@code "c"}, {@code "e"}, {@code "f"} or {@code "g"}. If the character after the {@code [} is a {@code !} then it is used for negation so {@code [!a-c]} matches any character except {@code "a"}, {@code "b"}, or {@code "c"}. <p> Within a bracket expression the {@code *}, {@code ?} and {@code \} characters match themselves. The ({@code -}) character matches itself if it is the first character within the brackets, or the first character after the {@code !} if negating.</p></li> <li><p> The {@code { }} characters are a group of subpatterns, where the group matches if any subpattern in the group matches. The {@code ","} character is used to separate the subpatterns. Groups cannot be nested. </p></li> <li><p> Leading period<tt>/</tt>dot characters in file name are treated as regular characters in match operations. For example, the {@code "*"} glob pattern matches file name {@code ".login"}. The {@link java.nio.file.Files#isHidden} method may be used to test whether a file is considered hidden. </p></li> <li><p> All other characters match themselves in an implementation dependent manner. This includes characters representing any {@link java.nio.file.FileSystem#getSeparator name-separators}. </p></li> <li><p> The matching of {@link java.nio.file.Path#getRoot root} components is highly implementation-dependent and is not specified. </p></li> </ul> <p> When the syntax is "{@code regex}" then the pattern component is a regular expression as defined by the {@link java.util.regex.Pattern} class. <p> For both the glob and regex syntaxes, the matching details, such as whether the matching is case sensitive, are implementation-dependent and therefore not specified. @param {String} syntaxAndPattern The syntax and pattern @return {Object {java.nio.file.PathMatcher}} A path matcher that may be used to match paths against the pattern @throws IllegalArgumentException If the parameter does not take the form: {@code syntax:pattern} @throws java.util.regex.PatternSyntaxException If the pattern is invalid @throws UnsupportedOperationException If the pattern syntax is not known to the implementation @see Files#newDirectoryStream(Path,String) */ getPathMatcher : function( ) {}, /**Returns the {@code UserPrincipalLookupService} for this file system <i>(optional operation)</i>. The resulting lookup service may be used to lookup user or group names. <p> <b>Usage Example:</b> Suppose we want to make "joe" the owner of a file: <pre> UserPrincipalLookupService lookupService = FileSystems.getDefault().getUserPrincipalLookupService(); Files.setOwner(path, lookupService.lookupPrincipalByName("joe")); </pre> @throws UnsupportedOperationException If this {@code FileSystem} does not does have a lookup service @return {Object {java.nio.file.attribute.UserPrincipalLookupService}} The {@code UserPrincipalLookupService} for this file system */ getUserPrincipalLookupService : function( ) {}, /**Constructs a new {@link java.nio.file.WatchService} <i>(optional operation)</i>. <p> This method constructs a new watch service that may be used to watch registered objects for changes and events. @return {Object {java.nio.file.WatchService}} a new watch service @throws UnsupportedOperationException If this {@code FileSystem} does not support watching file system objects for changes and events. This exception is not thrown by {@code FileSystems} created by the default provider. @throws IOException If an I/O error occurs */ newWatchService : function( ) {}, };