| /* |
| * Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.nio.file; |
| |
| import java.nio.file.attribute.*; |
| import java.nio.file.spi.FileSystemProvider; |
| import java.util.Set; |
| import java.io.Closeable; |
| import java.io.IOException; |
| |
| /** |
| * 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 FileSystems#getDefault |
| * FileSystems.getDefault} method, provides access to the file system that is |
| * accessible to the Java virtual machine. The {@link 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 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 PathMatcher} that performs match operations on |
| * paths. </p></li> |
| * <li><p> The {@link #getFileStores getFileStores} method returns an iterator |
| * over the underlying {@link 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 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 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 ClosedFileSystemException} to be |
| * thrown. File systems created by the default {@link 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 |
| * 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 |
| */ |
| |
| public abstract class FileSystem |
| implements Closeable |
| { |
| /** |
| * Initializes a new instance of this class. |
| */ |
| protected FileSystem() { |
| } |
| |
| /** |
| * Returns the provider that created this file system. |
| * |
| * @return The provider that created this file system. |
| */ |
| public abstract FileSystemProvider provider(); |
| |
| /** |
| * 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 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 DirectoryStream directory-streams}, |
| * {@link WatchService watch-service}, and other closeable objects associated |
| * with this file system. The {@link 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 |
| */ |
| @Override |
| public abstract void close() throws IOException; |
| |
| /** |
| * Tells whether or not this file system is open. |
| * |
| * <p> File systems created by the default provider are always open. |
| * |
| * @return {@code true} if, and only if, this file system is open |
| */ |
| public abstract boolean isOpen(); |
| |
| /** |
| * Tells whether or not this file system allows only read-only access to |
| * its file stores. |
| * |
| * @return {@code true} if, and only if, this file system provides |
| * read-only access |
| */ |
| public abstract boolean isReadOnly(); |
| |
| /** |
| * 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 |
| * 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 The name separator |
| */ |
| public abstract String getSeparator(); |
| |
| /** |
| * 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 An object to iterate over the root directories |
| */ |
| public abstract Iterable<Path> getRootDirectories(); |
| |
| /** |
| * Returns an object to iterate over the underlying file stores. |
| * |
| * <p> The elements of the returned iterator are the {@link |
| * FileStore 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}{@code ("getFileStoreAttributes")}. 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 An object to iterate over the backing file stores |
| */ |
| public abstract Iterable<FileStore> getFileStores(); |
| |
| /** |
| * 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 FileStore#supportsFileAttributeView(String) |
| * supportsFileAttributeView(String)} method may be used to test if an |
| * underlying {@link FileStore} supports the file attributes identified by a |
| * file attribute view. |
| * |
| * @return An unmodifiable set of the names of the supported file attribute |
| * views |
| */ |
| public abstract Set<String> supportedFileAttributeViews(); |
| |
| /** |
| * 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 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 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 InvalidPathException} when the path string |
| * cannot be converted to a path. Where possible, and where applicable, |
| * the exception is created with an {@link InvalidPathException#getIndex |
| * index} value indicating the first position in the {@code path} parameter |
| * that caused the path string to be rejected. |
| * |
| * @param first |
| * the path string or initial part of the path string |
| * @param more |
| * additional strings to be joined to form the path string |
| * |
| * @return the resulting {@code Path} |
| * |
| * @throws InvalidPathException |
| * If the path string cannot be converted |
| */ |
| public abstract Path getPath(String first, String... more); |
| |
| /** |
| * Returns a {@code PathMatcher} that performs match operations on the |
| * {@code String} representation of {@link 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><code>/home/*/*</code> |
| * <td>Matches <code>/home/gus/data</code> on UNIX platforms</td> |
| * </tr> |
| * <tr> |
| * <td><code>/home/**</code> |
| * <td>Matches <code>/home/gus</code> and |
| * <code>/home/gus/data</code> on UNIX platforms</td> |
| * </tr> |
| * <tr> |
| * <td><code>C:\\*</code> |
| * <td>Matches <code>C:\foo</code> and <code>C:\bar</code> on the Windows |
| * platform (note that the backslash is escaped; as a string literal in the |
| * Java Language the pattern would be <code>"C:\\\\*"</code>) </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 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<code>/</code>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 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 |
| * FileSystem#getSeparator name-separators}. </p></li> |
| * |
| * <li><p> The matching of {@link 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 syntaxAndPattern |
| * The syntax and pattern |
| * |
| * @return 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) |
| */ |
| public abstract PathMatcher getPathMatcher(String syntaxAndPattern); |
| |
| /** |
| * 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 The {@code UserPrincipalLookupService} for this file system |
| */ |
| public abstract UserPrincipalLookupService getUserPrincipalLookupService(); |
| |
| /** |
| * Constructs a new {@link 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 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 |
| */ |
| public abstract WatchService newWatchService() throws IOException; |
| } |
