User interfaces and operating systems use system-dependent pathname + * strings to name files and directories. This class presents an + * abstract, system-independent view of hierarchical pathnames. An + * abstract pathname has two components: + * + *
"/" for the UNIX root
+ * directory, or "\\\\" for a Microsoft Windows UNC pathname, and
+ * The conversion of a pathname string to or from an abstract pathname is
+ * inherently system-dependent. When an abstract pathname is converted into a
+ * pathname string, each name is separated from the next by a single copy of
+ * the default separator character. The default name-separator
+ * character is defined by the system property file.separator, and
+ * is made available in the public static fields {@link
+ * #separator} and {@link #separatorChar} of this class.
+ * When a pathname string is converted into an abstract pathname, the names
+ * within it may be separated by the default name-separator character or by any
+ * other name-separator character that is supported by the underlying system.
+ *
+ *
A pathname, whether abstract or in string form, may be either
+ * absolute or relative. An absolute pathname is complete in
+ * that no other information is required in order to locate the file that it
+ * denotes. A relative pathname, in contrast, must be interpreted in terms of
+ * information taken from some other pathname. By default the classes in the
+ * java.io package always resolve relative pathnames against the
+ * current user directory. This directory is named by the system property
+ * user.dir, and is typically the directory in which the Java
+ * virtual machine was invoked.
+ *
+ *
The parent of an abstract pathname may be obtained by invoking + * the {@link #getParent} method of this class and consists of the pathname's + * prefix and each name in the pathname's name sequence except for the last. + * Each directory's absolute pathname is an ancestor of any File + * object with an absolute abstract pathname which begins with the directory's + * absolute pathname. For example, the directory denoted by the abstract + * pathname "/usr" is an ancestor of the directory denoted by the + * pathname "/usr/local/bin". + * + *
The prefix concept is used to handle root directories on UNIX platforms, + * and drive specifiers, root directories and UNC pathnames on Microsoft Windows platforms, + * as follows: + * + *
"/". Relative pathnames have no prefix. The abstract pathname
+ * denoting the root directory has the prefix "/" and an empty
+ * name sequence.
+ *
+ * ":" and
+ * possibly followed by "\\" if the pathname is absolute. The
+ * prefix of a UNC pathname is "\\\\"; the hostname and the share
+ * name are the first two names in the name sequence. A relative pathname that
+ * does not specify a drive has no prefix.
+ *
+ * Instances of this class may or may not denote an actual file-system + * object such as a file or a directory. If it does denote such an object + * then that object resides in a partition. A partition is an + * operating system-specific portion of storage for a file system. A single + * storage device (e.g. a physical disk-drive, flash memory, CD-ROM) may + * contain multiple partitions. The object, if any, will reside on the + * partition named by some ancestor of the absolute + * form of this pathname. + * + *
A file system may implement restrictions to certain operations on the + * actual file-system object, such as reading, writing, and executing. These + * restrictions are collectively known as access permissions. The file + * system may have multiple sets of access permissions on a single object. + * For example, one set may apply to the object's owner, and another + * may apply to all other users. The access permissions on an object may + * cause some methods in this class to fail. + * + *
Instances of the File class are immutable; that is, once
+ * created, the abstract pathname represented by a File object
+ * will never change.
+ *
+ *
The {@code java.nio.file}
+ * package defines interfaces and classes for the Java virtual machine to access
+ * files, file attributes, and file systems. This API may be used to overcome
+ * many of the limitations of the {@code java.io.File} class.
+ * The {@link #toPath toPath} method may be used to obtain a {@link
+ * Path} that uses the abstract path represented by a {@code File} object to
+ * locate a file. The resulting {@code Path} may be used with the {@link
+ * java.nio.file.Files} class to provide more efficient and extensive access to
+ * additional file operations, file attributes, and I/O exceptions to help
+ * diagnose errors when an operation on a file fails.
+ *
+ * @author unascribed
+ * @since JDK1.0
+ */
+
+public class File
+ implements Serializable, Comparable If Otherwise the If Otherwise the The exact form of a file: URI is system-dependent, hence
+ * the transformation performed by this constructor is also
+ * system-dependent.
+ *
+ * For a given abstract pathname f it is guaranteed that
+ *
+ * The parent of an abstract pathname consists of the
+ * pathname's prefix, if any, and each name in the pathname's name
+ * sequence except for the last. If the name sequence is empty then
+ * the pathname does not name a parent directory.
+ *
+ * @return The pathname string of the parent directory named by this
+ * abstract pathname, or The parent of an abstract pathname consists of the
+ * pathname's prefix, if any, and each name in the pathname's name
+ * sequence except for the last. If the name sequence is empty then
+ * the pathname does not name a parent directory.
+ *
+ * @return The abstract pathname of the parent directory named by this
+ * abstract pathname, or If this abstract pathname is already absolute, then the pathname
+ * string is simply returned as if by the A canonical pathname is both absolute and unique. The precise
+ * definition of canonical form is system-dependent. This method first
+ * converts this pathname to absolute form if necessary, as if by invoking the
+ * {@link #getAbsolutePath} method, and then maps it to its unique form in a
+ * system-dependent way. This typically involves removing redundant names
+ * such as "." and ".." from the pathname, resolving
+ * symbolic links (on UNIX platforms), and converting drive letters to a
+ * standard case (on Microsoft Windows platforms).
+ *
+ * Every pathname that denotes an existing file or directory has a
+ * unique canonical form. Every pathname that denotes a nonexistent file
+ * or directory also has a unique canonical form. The canonical form of
+ * the pathname of a nonexistent file or directory may be different from
+ * the canonical form of the same pathname after the file or directory is
+ * created. Similarly, the canonical form of the pathname of an existing
+ * file or directory may be different from the canonical form of the same
+ * pathname after the file or directory is deleted.
+ *
+ * @return The canonical pathname string denoting the same file or
+ * directory as this abstract pathname
+ *
+ * @throws IOException
+ * If an I/O error occurs, which is possible because the
+ * construction of the canonical pathname may require
+ * filesystem queries
+ *
+ * @throws SecurityException
+ * If a required system property value cannot be accessed, or
+ * if a security manager exists and its The exact form of the URI is system-dependent. If it can be
+ * determined that the file denoted by this abstract pathname is a
+ * directory, then the resulting URI will end with a slash.
+ *
+ * For a given abstract pathname f, it is guaranteed that
+ *
+ * Note that when this abstract pathname represents a UNC pathname then
+ * all components of the UNC (including the server name component) are encoded
+ * in the {@code URI} path. The authority component is undefined, meaning
+ * that it is represented as {@code null}. The {@link Path} class defines the
+ * {@link Path#toUri toUri} method to encode the server name in the authority
+ * component of the resulting {@code URI}. The {@link #toPath toPath} method
+ * may be used to obtain a {@code Path} representing this abstract pathname.
+ *
+ * @return An absolute, hierarchical URI with a scheme equal to
+ * "file", a path representing this abstract pathname,
+ * and undefined authority, query, and fragment components
+ * @throws SecurityException If a required system property value cannot
+ * be accessed.
+ *
+ * @see #File(java.net.URI)
+ * @see java.net.URI
+ * @see java.net.URI#toURL()
+ * @since 1.4
+ */
+ public URI toURI() {
+ try {
+ File f = getAbsoluteFile();
+ String sp = slashify(f.getPath(), f.isDirectory());
+ if (sp.startsWith("//"))
+ sp = "//" + sp;
+ return new URI("file", null, sp, null);
+ } catch (URISyntaxException x) {
+ throw new Error(x); // Can't happen
+ }
+ }
+
+
+ /* -- Attribute accessors -- */
+
+ /**
+ * Tests whether the application can read the file denoted by this
+ * abstract pathname.
+ *
+ * @return Where it is required to distinguish an I/O exception from the case
+ * that the file is not a directory, or where several attributes of the
+ * same file are required at the same time, then the {@link
+ * java.nio.file.Files#readAttributes(Path,Class,LinkOption[])
+ * Files.readAttributes} method may be used.
+ *
+ * @return Where it is required to distinguish an I/O exception from the case
+ * that the file is not a normal file, or where several attributes of the
+ * same file are required at the same time, then the {@link
+ * java.nio.file.Files#readAttributes(Path,Class,LinkOption[])
+ * Files.readAttributes} method may be used.
+ *
+ * @return Where it is required to distinguish an I/O exception from the case
+ * where {@code 0L} is returned, or where several attributes of the
+ * same file are required at the same time, or where the time of last
+ * access or the creation time are required, then the {@link
+ * java.nio.file.Files#readAttributes(Path,Class,LinkOption[])
+ * Files.readAttributes} method may be used.
+ *
+ * @return A Where it is required to distinguish an I/O exception from the case
+ * that {@code 0L} is returned, or where several attributes of the same file
+ * are required at the same time, then the {@link
+ * java.nio.file.Files#readAttributes(Path,Class,LinkOption[])
+ * Files.readAttributes} method may be used.
+ *
+ * @return The length, in bytes, of the file denoted by this abstract
+ * pathname, or
+ * Note: this method should not be used for file-locking, as
+ * the resulting protocol cannot be made to work reliably. The
+ * {@link java.nio.channels.FileLock FileLock}
+ * facility should be used instead.
+ *
+ * @return Note that the {@link java.nio.file.Files} class defines the {@link
+ * java.nio.file.Files#delete(Path) delete} method to throw an {@link IOException}
+ * when a file cannot be deleted. This is useful for error reporting and to
+ * diagnose why a file cannot be deleted.
+ *
+ * @return Once deletion has been requested, it is not possible to cancel the
+ * request. This method should therefore be used with care.
+ *
+ *
+ * Note: this method should not be used for file-locking, as
+ * the resulting protocol cannot be made to work reliably. The
+ * {@link java.nio.channels.FileLock FileLock}
+ * facility should be used instead.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its If this abstract pathname does not denote a directory, then this
+ * method returns {@code null}. Otherwise an array of strings is
+ * returned, one for each file or directory in the directory. Names
+ * denoting the directory itself and the directory's parent directory are
+ * not included in the result. Each string is a file name rather than a
+ * complete path.
+ *
+ * There is no guarantee that the name strings in the resulting array
+ * will appear in any specific order; they are not, in particular,
+ * guaranteed to appear in alphabetical order.
+ *
+ * Note that the {@link java.nio.file.Files} class defines the {@link
+ * java.nio.file.Files#newDirectoryStream(Path) newDirectoryStream} method to
+ * open a directory and iterate over the names of the files in the directory.
+ * This may use less resources when working with very large directories, and
+ * may be more responsive when working with remote directories.
+ *
+ * @return An array of strings naming the files and directories in the
+ * directory denoted by this abstract pathname. The array will be
+ * empty if the directory is empty. Returns {@code null} if
+ * this abstract pathname does not denote a directory, or if an
+ * I/O error occurs.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * SecurityManager#checkRead(String)} method denies read access to
+ * the directory
+ */
+ public String[] list() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkRead(path);
+ }
+ return fs.list(this);
+ }
+
+ /**
+ * Returns an array of strings naming the files and directories in the
+ * directory denoted by this abstract pathname that satisfy the specified
+ * filter. The behavior of this method is the same as that of the
+ * {@link #list()} method, except that the strings in the returned array
+ * must satisfy the filter. If the given {@code filter} is {@code null}
+ * then all names are accepted. Otherwise, a name satisfies the filter if
+ * and only if the value {@code true} results when the {@link
+ * FilenameFilter#accept FilenameFilter.accept(File, String)} method
+ * of the filter is invoked on this abstract pathname and the name of a
+ * file or directory in the directory that it denotes.
+ *
+ * @param filter
+ * A filename filter
+ *
+ * @return An array of strings naming the files and directories in the
+ * directory denoted by this abstract pathname that were accepted
+ * by the given {@code filter}. The array will be empty if the
+ * directory is empty or if no names were accepted by the filter.
+ * Returns {@code null} if this abstract pathname does not denote
+ * a directory, or if an I/O error occurs.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * SecurityManager#checkRead(String)} method denies read access to
+ * the directory
+ *
+ * @see java.nio.file.Files#newDirectoryStream(Path,String)
+ */
+ public String[] list(FilenameFilter filter) {
+ String names[] = list();
+ if ((names == null) || (filter == null)) {
+ return names;
+ }
+ List If this abstract pathname does not denote a directory, then this
+ * method returns {@code null}. Otherwise an array of {@code File} objects
+ * is returned, one for each file or directory in the directory. Pathnames
+ * denoting the directory itself and the directory's parent directory are
+ * not included in the result. Each resulting abstract pathname is
+ * constructed from this abstract pathname using the {@link #File(File,
+ * String) File(File, String)} constructor. Therefore if this
+ * pathname is absolute then each resulting pathname is absolute; if this
+ * pathname is relative then each resulting pathname will be relative to
+ * the same directory.
+ *
+ * There is no guarantee that the name strings in the resulting array
+ * will appear in any specific order; they are not, in particular,
+ * guaranteed to appear in alphabetical order.
+ *
+ * Note that the {@link java.nio.file.Files} class defines the {@link
+ * java.nio.file.Files#newDirectoryStream(Path) newDirectoryStream} method
+ * to open a directory and iterate over the names of the files in the
+ * directory. This may use less resources when working with very large
+ * directories.
+ *
+ * @return An array of abstract pathnames denoting the files and
+ * directories in the directory denoted by this abstract pathname.
+ * The array will be empty if the directory is empty. Returns
+ * {@code null} if this abstract pathname does not denote a
+ * directory, or if an I/O error occurs.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * SecurityManager#checkRead(String)} method denies read access to
+ * the directory
+ *
+ * @since 1.2
+ */
+ public File[] listFiles() {
+ String[] ss = list();
+ if (ss == null) return null;
+ int n = ss.length;
+ File[] fs = new File[n];
+ for (int i = 0; i < n; i++) {
+ fs[i] = new File(ss[i], this);
+ }
+ return fs;
+ }
+
+ /**
+ * Returns an array of abstract pathnames denoting the files and
+ * directories in the directory denoted by this abstract pathname that
+ * satisfy the specified filter. The behavior of this method is the same
+ * as that of the {@link #listFiles()} method, except that the pathnames in
+ * the returned array must satisfy the filter. If the given {@code filter}
+ * is {@code null} then all pathnames are accepted. Otherwise, a pathname
+ * satisfies the filter if and only if the value {@code true} results when
+ * the {@link FilenameFilter#accept
+ * FilenameFilter.accept(File, String)} method of the filter is
+ * invoked on this abstract pathname and the name of a file or directory in
+ * the directory that it denotes.
+ *
+ * @param filter
+ * A filename filter
+ *
+ * @return An array of abstract pathnames denoting the files and
+ * directories in the directory denoted by this abstract pathname.
+ * The array will be empty if the directory is empty. Returns
+ * {@code null} if this abstract pathname does not denote a
+ * directory, or if an I/O error occurs.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * SecurityManager#checkRead(String)} method denies read access to
+ * the directory
+ *
+ * @since 1.2
+ * @see java.nio.file.Files#newDirectoryStream(Path,String)
+ */
+ public File[] listFiles(FilenameFilter filter) {
+ String ss[] = list();
+ if (ss == null) return null;
+ ArrayList Many aspects of the behavior of this method are inherently
+ * platform-dependent: The rename operation might not be able to move a
+ * file from one filesystem to another, it might not be atomic, and it
+ * might not succeed if a file with the destination abstract pathname
+ * already exists. The return value should always be checked to make sure
+ * that the rename operation was successful.
+ *
+ * Note that the {@link java.nio.file.Files} class defines the {@link
+ * java.nio.file.Files#move move} method to move or rename a file in a
+ * platform independent manner.
+ *
+ * @param dest The new abstract pathname for the named file
+ *
+ * @return All platforms support file-modification times to the nearest second,
+ * but some provide more precision. The argument will be truncated to fit
+ * the supported precision. If the operation succeeds and no intervening
+ * operations on the file take place, then the next invocation of the
+ * The {@link java.nio.file.Files} class defines methods that operate on
+ * file attributes including file permissions. This may be used when finer
+ * manipulation of file permissions is required.
+ *
+ * @param writable
+ * If An invocation of this method of the form file.setWritable(arg)
+ * behaves in exactly the same way as the invocation
+ *
+ * The {@link java.nio.file.Files} class defines methods that operate on
+ * file attributes including file permissions. This may be used when finer
+ * manipulation of file permissions is required.
+ *
+ * @param readable
+ * If An invocation of this method of the form file.setReadable(arg)
+ * behaves in exactly the same way as the invocation
+ *
+ * The {@link java.nio.file.Files} class defines methods that operate on
+ * file attributes including file permissions. This may be used when finer
+ * manipulation of file permissions is required.
+ *
+ * @param executable
+ * If An invocation of this method of the form file.setExcutable(arg)
+ * behaves in exactly the same way as the invocation
+ *
+ * A particular Java platform may support zero or more
+ * hierarchically-organized file systems. Each file system has a
+ * {@code root} directory from which all other files in that file system
+ * can be reached. Windows platforms, for example, have a root directory
+ * for each active drive; UNIX platforms have a single root directory,
+ * namely {@code "/"}. The set of available filesystem roots is affected
+ * by various system-level operations such as the insertion or ejection of
+ * removable media and the disconnecting or unmounting of physical or
+ * virtual disk drives.
+ *
+ * This method returns an array of {@code File} objects that denote the
+ * root directories of the available filesystem roots. It is guaranteed
+ * that the canonical pathname of any file physically present on the local
+ * machine will begin with one of the roots returned by this method.
+ *
+ * The canonical pathname of a file that resides on some other machine
+ * and is accessed via a remote-filesystem protocol such as SMB or NFS may
+ * or may not begin with one of the roots returned by this method. If the
+ * pathname of a remote file is syntactically indistinguishable from the
+ * pathname of a local file then it will begin with one of the roots
+ * returned by this method. Thus, for example, {@code File} objects
+ * denoting the root directories of the mapped network drives of a Windows
+ * platform will be returned by this method, while {@code File} objects
+ * containing UNC pathnames will not be returned by this method.
+ *
+ * Unlike most methods in this class, this method does not throw
+ * security exceptions. If a security manager exists and its {@link
+ * SecurityManager#checkRead(String)} method denies read access to a
+ * particular root directory, then that directory will not appear in the
+ * result.
+ *
+ * @return An array of {@code File} objects denoting the available
+ * filesystem roots, or {@code null} if the set of roots could not
+ * be determined. The array will be empty if there are no
+ * filesystem roots.
+ *
+ * @since 1.2
+ * @see java.nio.file.FileStore
+ */
+ public static File[] listRoots() {
+ return fs.listRoots();
+ }
+
+
+ /* -- Disk usage -- */
+
+ /**
+ * Returns the size of the partition named by this
+ * abstract pathname.
+ *
+ * @return The size, in bytes, of the partition or 0L if this
+ * abstract pathname does not name a partition
+ *
+ * @throws SecurityException
+ * If a security manager has been installed and it denies
+ * {@link RuntimePermission}("getFileSystemAttributes")
+ * or its {@link SecurityManager#checkRead(String)} method denies
+ * read access to the file named by this abstract pathname
+ *
+ * @since 1.6
+ */
+ public long getTotalSpace() {
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkPermission(new RuntimePermission("getFileSystemAttributes"));
+ sm.checkRead(path);
+ }
+ return fs.getSpace(this, FileSystem.SPACE_TOTAL);
+ }
+
+ /**
+ * Returns the number of unallocated bytes in the partition named by this abstract path name.
+ *
+ * The returned number of unallocated bytes is a hint, but not
+ * a guarantee, that it is possible to use most or any of these
+ * bytes. The number of unallocated bytes is most likely to be
+ * accurate immediately after this call. It is likely to be made
+ * inaccurate by any external I/O operations including those made
+ * on the system outside of this virtual machine. This method
+ * makes no guarantee that write operations to this file system
+ * will succeed.
+ *
+ * @return The number of unallocated bytes on the partition 0L
+ * if the abstract pathname does not name a partition. This
+ * value will be less than or equal to the total file system size
+ * returned by {@link #getTotalSpace}.
+ *
+ * @throws SecurityException
+ * If a security manager has been installed and it denies
+ * {@link RuntimePermission}("getFileSystemAttributes")
+ * or its {@link SecurityManager#checkRead(String)} method denies
+ * read access to the file named by this abstract pathname
+ *
+ * @since 1.6
+ */
+ public long getFreeSpace() {
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkPermission(new RuntimePermission("getFileSystemAttributes"));
+ sm.checkRead(path);
+ }
+ return fs.getSpace(this, FileSystem.SPACE_FREE);
+ }
+
+ /**
+ * Returns the number of bytes available to this virtual machine on the
+ * partition named by this abstract pathname. When
+ * possible, this method checks for write permissions and other operating
+ * system restrictions and will therefore usually provide a more accurate
+ * estimate of how much new data can actually be written than {@link
+ * #getFreeSpace}.
+ *
+ * The returned number of available bytes is a hint, but not a
+ * guarantee, that it is possible to use most or any of these bytes. The
+ * number of unallocated bytes is most likely to be accurate immediately
+ * after this call. It is likely to be made inaccurate by any external
+ * I/O operations including those made on the system outside of this
+ * virtual machine. This method makes no guarantee that write operations
+ * to this file system will succeed.
+ *
+ * @return The number of available bytes on the partition or 0L
+ * if the abstract pathname does not name a partition. On
+ * systems where this information is not available, this method
+ * will be equivalent to a call to {@link #getFreeSpace}.
+ *
+ * @throws SecurityException
+ * If a security manager has been installed and it denies
+ * {@link RuntimePermission}("getFileSystemAttributes")
+ * or its {@link SecurityManager#checkRead(String)} method denies
+ * read access to the file named by this abstract pathname
+ *
+ * @since 1.6
+ */
+ public long getUsableSpace() {
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkPermission(new RuntimePermission("getFileSystemAttributes"));
+ sm.checkRead(path);
+ }
+ return fs.getSpace(this, FileSystem.SPACE_USABLE);
+ }
+
+ /* -- Temporary files -- */
+
+ private static class TempDirectory {
+ private TempDirectory() { }
+
+ // temporary directory location
+ private static final File tmpdir = new File(fs.normalize(AccessController
+ .doPrivileged(new GetPropertyAction("java.io.tmpdir"))));
+ static File location() {
+ return tmpdir;
+ }
+
+ // file name generation
+ private static final SecureRandom random = new SecureRandom();
+ static File generateFile(String prefix, String suffix, File dir) {
+ long n = random.nextLong();
+ if (n == Long.MIN_VALUE) {
+ n = 0; // corner case
+ } else {
+ n = Math.abs(n);
+ }
+ return new File(dir, prefix + Long.toString(n) + suffix);
+ }
+ }
+
+ /**
+ * Creates a new empty file in the specified directory, using the
+ * given prefix and suffix strings to generate its name. If this method
+ * returns successfully then it is guaranteed that:
+ *
+ * The To create the new file, the prefix and the suffix may first be
+ * adjusted to fit the limitations of the underlying platform. If the
+ * prefix is too long then it will be truncated, but its first three
+ * characters will always be preserved. If the suffix is too long then it
+ * too will be truncated, but if it begins with a period character
+ * ( If the The {@link
+ * java.nio.file.Files#createTempFile(String,String,java.nio.file.attribute.FileAttribute[])
+ * Files.createTempFile} method provides an alternative method to create an
+ * empty file in the temporary-file directory. Files created by that method
+ * may have more restrictive access permissions to files created by this
+ * method and so may be more suited to security-sensitive applications.
+ *
+ * @param prefix The prefix string to be used in generating the file's
+ * name; must be at least three characters long
+ *
+ * @param suffix The suffix string to be used in generating the file's
+ * name; may be
+ * @serialData Default fields followed by separator character.
+ */
+ private synchronized void writeObject(java.io.ObjectOutputStream s)
+ throws IOException
+ {
+ s.defaultWriteObject();
+ s.writeChar(this.separatorChar); // Add the separator character
+ }
+
+ /**
+ * readObject is called to restore this filename.
+ * The original separator character is read. If it is different
+ * than the separator character on this system, then the old separator
+ * is replaced by the local separator.
+ */
+ private synchronized void readObject(java.io.ObjectInputStream s)
+ throws IOException, ClassNotFoundException
+ {
+ ObjectInputStream.GetField fields = s.readFields();
+ String pathField = (String)fields.get("path", null);
+ char sep = s.readChar(); // read the previous separator char
+ if (sep != separatorChar)
+ pathField = pathField.replace(sep, separatorChar);
+ this.path = fs.normalize(pathField);
+ this.prefixLength = fs.prefixLength(this.path);
+ }
+
+ /** use serialVersionUID from JDK 1.0.2 for interoperability */
+ private static final long serialVersionUID = 301077366599181567L;
+
+ // -- Integration with java.nio.file --
+
+ private volatile transient Path filePath;
+
+ /**
+ * Returns a {@link Path java.nio.file.Path} object constructed from the
+ * this abstract path. The resulting {@code Path} is associated with the
+ * {@link java.nio.file.FileSystems#getDefault default-filesystem}.
+ *
+ * The first invocation of this method works as if invoking it were
+ * equivalent to evaluating the expression:
+ * If this abstract pathname is the empty abstract pathname then this
+ * method returns a {@code Path} that may be used to access the current
+ * user directory.
+ *
+ * @return a {@code Path} constructed from this abstract path
+ *
+ * @throws java.nio.file.InvalidPathException
+ * if a {@code Path} object cannot be constructed from the abstract
+ * path (see {@link java.nio.file.FileSystem#getPath FileSystem.getPath})
+ *
+ * @since 1.7
+ * @see Path#toFile
+ */
+ public Path toPath() {
+ Path result = filePath;
+ if (result == null) {
+ synchronized (this) {
+ result = filePath;
+ if (result == null) {
+ result = FileSystems.getDefault().getPath(path);
+ filePath = result;
+ }
+ }
+ }
+ return result;
+ }
+}
file.separator. On UNIX systems the value of this
+ * field is '/'; on Microsoft Windows systems it is '\\'.
+ *
+ * @see java.lang.System#getProperty(java.lang.String)
+ */
+ public static final char separatorChar = fs.getSeparator();
+
+ /**
+ * The system-dependent default name-separator character, represented as a
+ * string for convenience. This string contains a single character, namely
+ * {@link #separatorChar}.
+ */
+ public static final String separator = "" + separatorChar;
+
+ /**
+ * The system-dependent path-separator character. This field is
+ * initialized to contain the first character of the value of the system
+ * property path.separator. This character is used to
+ * separate filenames in a sequence of files given as a path list.
+ * On UNIX systems, this character is ':'; on Microsoft Windows systems it
+ * is ';'.
+ *
+ * @see java.lang.System#getProperty(java.lang.String)
+ */
+ public static final char pathSeparatorChar = fs.getPathSeparator();
+
+ /**
+ * The system-dependent path-separator character, represented as a string
+ * for convenience. This string contains a single character, namely
+ * {@link #pathSeparatorChar}.
+ */
+ public static final String pathSeparator = "" + pathSeparatorChar;
+
+
+ /* -- Constructors -- */
+
+ /**
+ * Internal constructor for already-normalized pathname strings.
+ */
+ private File(String pathname, int prefixLength) {
+ this.path = pathname;
+ this.prefixLength = prefixLength;
+ }
+
+ /**
+ * Internal constructor for already-normalized pathname strings.
+ * The parameter order is used to disambiguate this method from the
+ * public(File, String) constructor.
+ */
+ private File(String child, File parent) {
+ assert parent.path != null;
+ assert (!parent.path.equals(""));
+ this.path = fs.resolve(parent.path, child);
+ this.prefixLength = parent.prefixLength;
+ }
+
+ /**
+ * Creates a new File instance by converting the given
+ * pathname string into an abstract pathname. If the given string is
+ * the empty string, then the result is the empty abstract pathname.
+ *
+ * @param pathname A pathname string
+ * @throws NullPointerException
+ * If the pathname argument is null
+ */
+ public File(String pathname) {
+ if (pathname == null) {
+ throw new NullPointerException();
+ }
+ this.path = fs.normalize(pathname);
+ this.prefixLength = fs.prefixLength(this.path);
+ }
+
+ /* Note: The two-argument File constructors do not interpret an empty
+ parent abstract pathname as the current user directory. An empty parent
+ instead causes the child to be resolved against the system-dependent
+ directory defined by the FileSystem.getDefaultParent method. On Unix
+ this default is "/", while on Microsoft Windows it is "\\". This is required for
+ compatibility with the original behavior of this class. */
+
+ /**
+ * Creates a new File instance from a parent pathname string
+ * and a child pathname string.
+ *
+ * parent is null then the new
+ * File instance is created as if by invoking the
+ * single-argument File constructor on the given
+ * child pathname string.
+ *
+ * parent pathname string is taken to denote
+ * a directory, and the child pathname string is taken to
+ * denote either a directory or a file. If the child pathname
+ * string is absolute then it is converted into a relative pathname in a
+ * system-dependent way. If parent is the empty string then
+ * the new File instance is created by converting
+ * child into an abstract pathname and resolving the result
+ * against a system-dependent default directory. Otherwise each pathname
+ * string is converted into an abstract pathname and the child abstract
+ * pathname is resolved against the parent.
+ *
+ * @param parent The parent pathname string
+ * @param child The child pathname string
+ * @throws NullPointerException
+ * If child is null
+ */
+ public File(String parent, String child) {
+ if (child == null) {
+ throw new NullPointerException();
+ }
+ if (parent != null) {
+ if (parent.equals("")) {
+ this.path = fs.resolve(fs.getDefaultParent(),
+ fs.normalize(child));
+ } else {
+ this.path = fs.resolve(fs.normalize(parent),
+ fs.normalize(child));
+ }
+ } else {
+ this.path = fs.normalize(child);
+ }
+ this.prefixLength = fs.prefixLength(this.path);
+ }
+
+ /**
+ * Creates a new File instance from a parent abstract
+ * pathname and a child pathname string.
+ *
+ * parent is null then the new
+ * File instance is created as if by invoking the
+ * single-argument File constructor on the given
+ * child pathname string.
+ *
+ * parent abstract pathname is taken to
+ * denote a directory, and the child pathname string is taken
+ * to denote either a directory or a file. If the child
+ * pathname string is absolute then it is converted into a relative
+ * pathname in a system-dependent way. If parent is the empty
+ * abstract pathname then the new File instance is created by
+ * converting child into an abstract pathname and resolving
+ * the result against a system-dependent default directory. Otherwise each
+ * pathname string is converted into an abstract pathname and the child
+ * abstract pathname is resolved against the parent.
+ *
+ * @param parent The parent abstract pathname
+ * @param child The child pathname string
+ * @throws NullPointerException
+ * If child is null
+ */
+ public File(File parent, String child) {
+ if (child == null) {
+ throw new NullPointerException();
+ }
+ if (parent != null) {
+ if (parent.path.equals("")) {
+ this.path = fs.resolve(fs.getDefaultParent(),
+ fs.normalize(child));
+ } else {
+ this.path = fs.resolve(parent.path,
+ fs.normalize(child));
+ }
+ } else {
+ this.path = fs.normalize(child);
+ }
+ this.prefixLength = fs.prefixLength(this.path);
+ }
+
+ /**
+ * Creates a new File instance by converting the given
+ * file: URI into an abstract pathname.
+ *
+ *
+ * new File( f.{@link #toURI() toURI}()).equals( f.{@link #getAbsoluteFile() getAbsoluteFile}())
+ *
+ *
+ * so long as the original abstract pathname, the URI, and the new abstract
+ * pathname are all created in (possibly different invocations of) the same
+ * Java virtual machine. This relationship typically does not hold,
+ * however, when a file: URI that is created in a virtual machine
+ * on one operating system is converted into an abstract pathname in a
+ * virtual machine on a different operating system.
+ *
+ * @param uri
+ * An absolute, hierarchical URI with a scheme equal to
+ * "file", a non-empty path component, and undefined
+ * authority, query, and fragment components
+ *
+ * @throws NullPointerException
+ * If uri is null
+ *
+ * @throws IllegalArgumentException
+ * If the preconditions on the parameter do not hold
+ *
+ * @see #toURI()
+ * @see java.net.URI
+ * @since 1.4
+ */
+ public File(URI uri) {
+
+ // Check our many preconditions
+ if (!uri.isAbsolute())
+ throw new IllegalArgumentException("URI is not absolute");
+ if (uri.isOpaque())
+ throw new IllegalArgumentException("URI is not hierarchical");
+ String scheme = uri.getScheme();
+ if ((scheme == null) || !scheme.equalsIgnoreCase("file"))
+ throw new IllegalArgumentException("URI scheme is not \"file\"");
+ if (uri.getAuthority() != null)
+ throw new IllegalArgumentException("URI has an authority component");
+ if (uri.getFragment() != null)
+ throw new IllegalArgumentException("URI has a fragment component");
+ if (uri.getQuery() != null)
+ throw new IllegalArgumentException("URI has a query component");
+ String p = uri.getPath();
+ if (p.equals(""))
+ throw new IllegalArgumentException("URI path component is empty");
+
+ // Okay, now initialize
+ p = fs.fromURIPath(p);
+ if (File.separatorChar != '/')
+ p = p.replace('/', File.separatorChar);
+ this.path = fs.normalize(p);
+ this.prefixLength = fs.prefixLength(this.path);
+ }
+
+
+ /* -- Path-component accessors -- */
+
+ /**
+ * Returns the name of the file or directory denoted by this abstract
+ * pathname. This is just the last name in the pathname's name
+ * sequence. If the pathname's name sequence is empty, then the empty
+ * string is returned.
+ *
+ * @return The name of the file or directory denoted by this abstract
+ * pathname, or the empty string if this pathname's name sequence
+ * is empty
+ */
+ public String getName() {
+ int index = path.lastIndexOf(separatorChar);
+ if (index < prefixLength) return path.substring(prefixLength);
+ return path.substring(index + 1);
+ }
+
+ /**
+ * Returns the pathname string of this abstract pathname's parent, or
+ * null if this pathname does not name a parent directory.
+ *
+ * null if this pathname
+ * does not name a parent
+ */
+ public String getParent() {
+ int index = path.lastIndexOf(separatorChar);
+ if (index < prefixLength) {
+ if ((prefixLength > 0) && (path.length() > prefixLength))
+ return path.substring(0, prefixLength);
+ return null;
+ }
+ return path.substring(0, index);
+ }
+
+ /**
+ * Returns the abstract pathname of this abstract pathname's parent,
+ * or null if this pathname does not name a parent
+ * directory.
+ *
+ * null if this pathname
+ * does not name a parent
+ *
+ * @since 1.2
+ */
+ public File getParentFile() {
+ String p = this.getParent();
+ if (p == null) return null;
+ return new File(p, this.prefixLength);
+ }
+
+ /**
+ * Converts this abstract pathname into a pathname string. The resulting
+ * string uses the {@link #separator default name-separator character} to
+ * separate the names in the name sequence.
+ *
+ * @return The string form of this abstract pathname
+ */
+ public String getPath() {
+ return path;
+ }
+
+
+ /* -- Path operations -- */
+
+ /**
+ * Tests whether this abstract pathname is absolute. The definition of
+ * absolute pathname is system dependent. On UNIX systems, a pathname is
+ * absolute if its prefix is "/". On Microsoft Windows systems, a
+ * pathname is absolute if its prefix is a drive specifier followed by
+ * "\\", or if its prefix is "\\\\".
+ *
+ * @return true if this abstract pathname is absolute,
+ * false otherwise
+ */
+ public boolean isAbsolute() {
+ return fs.isAbsolute(this);
+ }
+
+ /**
+ * Returns the absolute pathname string of this abstract pathname.
+ *
+ * {@link #getPath}
+ * method. If this abstract pathname is the empty abstract pathname then
+ * the pathname string of the current user directory, which is named by the
+ * system property user.dir, is returned. Otherwise this
+ * pathname is resolved in a system-dependent way. On UNIX systems, a
+ * relative pathname is made absolute by resolving it against the current
+ * user directory. On Microsoft Windows systems, a relative pathname is made absolute
+ * by resolving it against the current directory of the drive named by the
+ * pathname, if any; if not, it is resolved against the current user
+ * directory.
+ *
+ * @return The absolute pathname string denoting the same file or
+ * directory as this abstract pathname
+ *
+ * @throws SecurityException
+ * If a required system property value cannot be accessed.
+ *
+ * @see java.io.File#isAbsolute()
+ */
+ public String getAbsolutePath() {
+ return fs.resolve(this);
+ }
+
+ /**
+ * Returns the absolute form of this abstract pathname. Equivalent to
+ * new File(this.{@link #getAbsolutePath}).
+ *
+ * @return The absolute abstract pathname denoting the same file or
+ * directory as this abstract pathname
+ *
+ * @throws SecurityException
+ * If a required system property value cannot be accessed.
+ *
+ * @since 1.2
+ */
+ public File getAbsoluteFile() {
+ String absPath = getAbsolutePath();
+ return new File(absPath, fs.prefixLength(absPath));
+ }
+
+ /**
+ * Returns the canonical pathname string of this abstract pathname.
+ *
+ * {@link
+ * java.lang.SecurityManager#checkRead} method denies
+ * read access to the file
+ *
+ * @since JDK1.1
+ * @see Path#toRealPath
+ */
+ public String getCanonicalPath() throws IOException {
+ return fs.canonicalize(fs.resolve(this));
+ }
+
+ /**
+ * Returns the canonical form of this abstract pathname. Equivalent to
+ * new File(this.{@link #getCanonicalPath}).
+ *
+ * @return The canonical pathname string denoting the same file or
+ * directory as this abstract pathname
+ *
+ * @throws IOException
+ * If an I/O error occurs, which is possible because the
+ * construction of the canonical pathname may require
+ * filesystem queries
+ *
+ * @throws SecurityException
+ * If a required system property value cannot be accessed, or
+ * if a security manager exists and its {@link
+ * java.lang.SecurityManager#checkRead} method denies
+ * read access to the file
+ *
+ * @since 1.2
+ * @see Path#toRealPath
+ */
+ public File getCanonicalFile() throws IOException {
+ String canonPath = getCanonicalPath();
+ return new File(canonPath, fs.prefixLength(canonPath));
+ }
+
+ private static String slashify(String path, boolean isDirectory) {
+ String p = path;
+ if (File.separatorChar != '/')
+ p = p.replace(File.separatorChar, '/');
+ if (!p.startsWith("/"))
+ p = "/" + p;
+ if (!p.endsWith("/") && isDirectory)
+ p = p + "/";
+ return p;
+ }
+
+ /**
+ * Converts this abstract pathname into a file: URL. The
+ * exact form of the URL is system-dependent. If it can be determined that
+ * the file denoted by this abstract pathname is a directory, then the
+ * resulting URL will end with a slash.
+ *
+ * @return A URL object representing the equivalent file URL
+ *
+ * @throws MalformedURLException
+ * If the path cannot be parsed as a URL
+ *
+ * @see #toURI()
+ * @see java.net.URI
+ * @see java.net.URI#toURL()
+ * @see java.net.URL
+ * @since 1.2
+ *
+ * @deprecated This method does not automatically escape characters that
+ * are illegal in URLs. It is recommended that new code convert an
+ * abstract pathname into a URL by first converting it into a URI, via the
+ * {@link #toURI() toURI} method, and then converting the URI into a URL
+ * via the {@link java.net.URI#toURL() URI.toURL} method.
+ */
+ @Deprecated
+ public URL toURL() throws MalformedURLException {
+ return new URL("file", "", slashify(getAbsolutePath(), isDirectory()));
+ }
+
+ /**
+ * Constructs a file: URI that represents this abstract pathname.
+ *
+ *
+ * new {@link #File(java.net.URI) File}( f.toURI()).equals( f.{@link #getAbsoluteFile() getAbsoluteFile}())
+ *
+ *
+ * so long as the original abstract pathname, the URI, and the new abstract
+ * pathname are all created in (possibly different invocations of) the same
+ * Java virtual machine. Due to the system-dependent nature of abstract
+ * pathnames, however, this relationship typically does not hold when a
+ * file: URI that is created in a virtual machine on one operating
+ * system is converted into an abstract pathname in a virtual machine on a
+ * different operating system.
+ *
+ * true if and only if the file specified by this
+ * abstract pathname exists and can be read by the
+ * application; false otherwise
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkRead(java.lang.String)}
+ * method denies read access to the file
+ */
+ public boolean canRead() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkRead(path);
+ }
+ return fs.checkAccess(this, FileSystem.ACCESS_READ);
+ }
+
+ /**
+ * Tests whether the application can modify the file denoted by this
+ * abstract pathname.
+ *
+ * @return true if and only if the file system actually
+ * contains a file denoted by this abstract pathname and
+ * the application is allowed to write to the file;
+ * false otherwise.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method denies write access to the file
+ */
+ public boolean canWrite() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkWrite(path);
+ }
+ return fs.checkAccess(this, FileSystem.ACCESS_WRITE);
+ }
+
+ /**
+ * Tests whether the file or directory denoted by this abstract pathname
+ * exists.
+ *
+ * @return true if and only if the file or directory denoted
+ * by this abstract pathname exists; false otherwise
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkRead(java.lang.String)}
+ * method denies read access to the file or directory
+ */
+ public boolean exists() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkRead(path);
+ }
+ return ((fs.getBooleanAttributes(this) & FileSystem.BA_EXISTS) != 0);
+ }
+
+ /**
+ * Tests whether the file denoted by this abstract pathname is a
+ * directory.
+ *
+ * true if and only if the file denoted by this
+ * abstract pathname exists and is a directory;
+ * false otherwise
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkRead(java.lang.String)}
+ * method denies read access to the file
+ */
+ public boolean isDirectory() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkRead(path);
+ }
+ return ((fs.getBooleanAttributes(this) & FileSystem.BA_DIRECTORY)
+ != 0);
+ }
+
+ /**
+ * Tests whether the file denoted by this abstract pathname is a normal
+ * file. A file is normal if it is not a directory and, in
+ * addition, satisfies other system-dependent criteria. Any non-directory
+ * file created by a Java application is guaranteed to be a normal file.
+ *
+ * true if and only if the file denoted by this
+ * abstract pathname exists and is a normal file;
+ * false otherwise
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkRead(java.lang.String)}
+ * method denies read access to the file
+ */
+ public boolean isFile() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkRead(path);
+ }
+ return ((fs.getBooleanAttributes(this) & FileSystem.BA_REGULAR) != 0);
+ }
+
+ /**
+ * Tests whether the file named by this abstract pathname is a hidden
+ * file. The exact definition of hidden is system-dependent. On
+ * UNIX systems, a file is considered to be hidden if its name begins with
+ * a period character ('.'). On Microsoft Windows systems, a file is
+ * considered to be hidden if it has been marked as such in the filesystem.
+ *
+ * @return true if and only if the file denoted by this
+ * abstract pathname is hidden according to the conventions of the
+ * underlying platform
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkRead(java.lang.String)}
+ * method denies read access to the file
+ *
+ * @since 1.2
+ */
+ public boolean isHidden() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkRead(path);
+ }
+ return ((fs.getBooleanAttributes(this) & FileSystem.BA_HIDDEN) != 0);
+ }
+
+ /**
+ * Returns the time that the file denoted by this abstract pathname was
+ * last modified.
+ *
+ * long value representing the time the file was
+ * last modified, measured in milliseconds since the epoch
+ * (00:00:00 GMT, January 1, 1970), or 0L if the
+ * file does not exist or if an I/O error occurs
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkRead(java.lang.String)}
+ * method denies read access to the file
+ */
+ public long lastModified() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkRead(path);
+ }
+ return fs.getLastModifiedTime(this);
+ }
+
+ /**
+ * Returns the length of the file denoted by this abstract pathname.
+ * The return value is unspecified if this pathname denotes a directory.
+ *
+ * 0L if the file does not exist. Some
+ * operating systems may return 0L for pathnames
+ * denoting system-dependent entities such as devices or pipes.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkRead(java.lang.String)}
+ * method denies read access to the file
+ */
+ public long length() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkRead(path);
+ }
+ return fs.getLength(this);
+ }
+
+
+ /* -- File operations -- */
+
+ /**
+ * Atomically creates a new, empty file named by this abstract pathname if
+ * and only if a file with this name does not yet exist. The check for the
+ * existence of the file and the creation of the file if it does not exist
+ * are a single operation that is atomic with respect to all other
+ * filesystem activities that might affect the file.
+ * true if the named file does not exist and was
+ * successfully created; false if the named file
+ * already exists
+ *
+ * @throws IOException
+ * If an I/O error occurred
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method denies write access to the file
+ *
+ * @since 1.2
+ */
+ public boolean createNewFile() throws IOException {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) security.checkWrite(path);
+ return fs.createFileExclusively(path);
+ }
+
+ /**
+ * Deletes the file or directory denoted by this abstract pathname. If
+ * this pathname denotes a directory, then the directory must be empty in
+ * order to be deleted.
+ *
+ * true if and only if the file or directory is
+ * successfully deleted; false otherwise
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkDelete} method denies
+ * delete access to the file
+ */
+ public boolean delete() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkDelete(path);
+ }
+ return fs.delete(this);
+ }
+
+ /**
+ * Requests that the file or directory denoted by this abstract
+ * pathname be deleted when the virtual machine terminates.
+ * Files (or directories) are deleted in the reverse order that
+ * they are registered. Invoking this method to delete a file or
+ * directory that is already registered for deletion has no effect.
+ * Deletion will be attempted only for normal termination of the
+ * virtual machine, as defined by the Java Language Specification.
+ *
+ * {@link
+ * java.lang.SecurityManager#checkDelete} method denies
+ * delete access to the file
+ *
+ * @see #delete
+ *
+ * @since 1.2
+ */
+ public void deleteOnExit() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkDelete(path);
+ }
+ DeleteOnExitHook.add(path);
+ }
+
+ /**
+ * Returns an array of strings naming the files and directories in the
+ * directory denoted by this abstract pathname.
+ *
+ * true if and only if the directory was
+ * created; false otherwise
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method does not permit the named directory to be created
+ */
+ public boolean mkdir() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkWrite(path);
+ }
+ return fs.createDirectory(this);
+ }
+
+ /**
+ * Creates the directory named by this abstract pathname, including any
+ * necessary but nonexistent parent directories. Note that if this
+ * operation fails it may have succeeded in creating some of the necessary
+ * parent directories.
+ *
+ * @return true if and only if the directory was created,
+ * along with all necessary parent directories; false
+ * otherwise
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkRead(java.lang.String)}
+ * method does not permit verification of the existence of the
+ * named directory and all necessary parent directories; or if
+ * the {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method does not permit the named directory and all necessary
+ * parent directories to be created
+ */
+ public boolean mkdirs() {
+ if (exists()) {
+ return false;
+ }
+ if (mkdir()) {
+ return true;
+ }
+ File canonFile = null;
+ try {
+ canonFile = getCanonicalFile();
+ } catch (IOException e) {
+ return false;
+ }
+
+ File parent = canonFile.getParentFile();
+ return (parent != null && (parent.mkdirs() || parent.exists()) &&
+ canonFile.mkdir());
+ }
+
+ /**
+ * Renames the file denoted by this abstract pathname.
+ *
+ * true if and only if the renaming succeeded;
+ * false otherwise
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method denies write access to either the old or new pathnames
+ *
+ * @throws NullPointerException
+ * If parameter dest is null
+ */
+ public boolean renameTo(File dest) {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkWrite(path);
+ security.checkWrite(dest.path);
+ }
+ return fs.rename(this, dest);
+ }
+
+ /**
+ * Sets the last-modified time of the file or directory named by this
+ * abstract pathname.
+ *
+ * {@link #lastModified} method will return the (possibly
+ * truncated) time argument that was passed to this method.
+ *
+ * @param time The new last-modified time, measured in milliseconds since
+ * the epoch (00:00:00 GMT, January 1, 1970)
+ *
+ * @return true if and only if the operation succeeded;
+ * false otherwise
+ *
+ * @throws IllegalArgumentException If the argument is negative
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method denies write access to the named file
+ *
+ * @since 1.2
+ */
+ public boolean setLastModified(long time) {
+ if (time < 0) throw new IllegalArgumentException("Negative time");
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkWrite(path);
+ }
+ return fs.setLastModifiedTime(this, time);
+ }
+
+ /**
+ * Marks the file or directory named by this abstract pathname so that
+ * only read operations are allowed. After invoking this method the file
+ * or directory is guaranteed not to change until it is either deleted or
+ * marked to allow write access. Whether or not a read-only file or
+ * directory may be deleted depends upon the underlying system.
+ *
+ * @return true if and only if the operation succeeded;
+ * false otherwise
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method denies write access to the named file
+ *
+ * @since 1.2
+ */
+ public boolean setReadOnly() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkWrite(path);
+ }
+ return fs.setReadOnly(this);
+ }
+
+ /**
+ * Sets the owner's or everybody's write permission for this abstract
+ * pathname.
+ *
+ * true, sets the access permission to allow write
+ * operations; if false to disallow write operations
+ *
+ * @param ownerOnly
+ * If true, the write permission applies only to the
+ * owner's write permission; otherwise, it applies to everybody. If
+ * the underlying file system can not distinguish the owner's write
+ * permission from that of others, then the permission will apply to
+ * everybody, regardless of this value.
+ *
+ * @return true if and only if the operation succeeded. The
+ * operation will fail if the user does not have permission to change
+ * the access permissions of this abstract pathname.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method denies write access to the named file
+ *
+ * @since 1.6
+ */
+ public boolean setWritable(boolean writable, boolean ownerOnly) {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkWrite(path);
+ }
+ return fs.setPermission(this, FileSystem.ACCESS_WRITE, writable, ownerOnly);
+ }
+
+ /**
+ * A convenience method to set the owner's write permission for this abstract
+ * pathname.
+ *
+ *
+ * file.setWritable(arg, true)
+ *
+ * @param writable
+ * If true, sets the access permission to allow write
+ * operations; if false to disallow write operations
+ *
+ * @return true if and only if the operation succeeded. The
+ * operation will fail if the user does not have permission to
+ * change the access permissions of this abstract pathname.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method denies write access to the file
+ *
+ * @since 1.6
+ */
+ public boolean setWritable(boolean writable) {
+ return setWritable(writable, true);
+ }
+
+ /**
+ * Sets the owner's or everybody's read permission for this abstract
+ * pathname.
+ *
+ * true, sets the access permission to allow read
+ * operations; if false to disallow read operations
+ *
+ * @param ownerOnly
+ * If true, the read permission applies only to the
+ * owner's read permission; otherwise, it applies to everybody. If
+ * the underlying file system can not distinguish the owner's read
+ * permission from that of others, then the permission will apply to
+ * everybody, regardless of this value.
+ *
+ * @return true if and only if the operation succeeded. The
+ * operation will fail if the user does not have permission to
+ * change the access permissions of this abstract pathname. If
+ * readable is false and the underlying
+ * file system does not implement a read permission, then the
+ * operation will fail.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method denies write access to the file
+ *
+ * @since 1.6
+ */
+ public boolean setReadable(boolean readable, boolean ownerOnly) {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkWrite(path);
+ }
+ return fs.setPermission(this, FileSystem.ACCESS_READ, readable, ownerOnly);
+ }
+
+ /**
+ * A convenience method to set the owner's read permission for this abstract
+ * pathname.
+ *
+ *
+ * file.setReadable(arg, true)
+ *
+ * @param readable
+ * If true, sets the access permission to allow read
+ * operations; if false to disallow read operations
+ *
+ * @return true if and only if the operation succeeded. The
+ * operation will fail if the user does not have permission to
+ * change the access permissions of this abstract pathname. If
+ * readable is false and the underlying
+ * file system does not implement a read permission, then the
+ * operation will fail.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method denies write access to the file
+ *
+ * @since 1.6
+ */
+ public boolean setReadable(boolean readable) {
+ return setReadable(readable, true);
+ }
+
+ /**
+ * Sets the owner's or everybody's execute permission for this abstract
+ * pathname.
+ *
+ * true, sets the access permission to allow execute
+ * operations; if false to disallow execute operations
+ *
+ * @param ownerOnly
+ * If true, the execute permission applies only to the
+ * owner's execute permission; otherwise, it applies to everybody.
+ * If the underlying file system can not distinguish the owner's
+ * execute permission from that of others, then the permission will
+ * apply to everybody, regardless of this value.
+ *
+ * @return true if and only if the operation succeeded. The
+ * operation will fail if the user does not have permission to
+ * change the access permissions of this abstract pathname. If
+ * executable is false and the underlying
+ * file system does not implement an execute permission, then the
+ * operation will fail.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method denies write access to the file
+ *
+ * @since 1.6
+ */
+ public boolean setExecutable(boolean executable, boolean ownerOnly) {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkWrite(path);
+ }
+ return fs.setPermission(this, FileSystem.ACCESS_EXECUTE, executable, ownerOnly);
+ }
+
+ /**
+ * A convenience method to set the owner's execute permission for this abstract
+ * pathname.
+ *
+ *
+ * file.setExecutable(arg, true)
+ *
+ * @param executable
+ * If true, sets the access permission to allow execute
+ * operations; if false to disallow execute operations
+ *
+ * @return true if and only if the operation succeeded. The
+ * operation will fail if the user does not have permission to
+ * change the access permissions of this abstract pathname. If
+ * executable is false and the underlying
+ * file system does not implement an excute permission, then the
+ * operation will fail.
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method denies write access to the file
+ *
+ * @since 1.6
+ */
+ public boolean setExecutable(boolean executable) {
+ return setExecutable(executable, true);
+ }
+
+ /**
+ * Tests whether the application can execute the file denoted by this
+ * abstract pathname.
+ *
+ * @return true if and only if the abstract pathname exists
+ * and the application is allowed to execute the file
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkExec(java.lang.String)}
+ * method denies execute access to the file
+ *
+ * @since 1.6
+ */
+ public boolean canExecute() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkExec(path);
+ }
+ return fs.checkAccess(this, FileSystem.ACCESS_EXECUTE);
+ }
+
+
+ /* -- Filesystem interface -- */
+
+ /**
+ * List the available filesystem roots.
+ *
+ *
+ *
+ *
+ * This method provides only part of a temporary-file facility. To arrange
+ * for a file created by this method to be deleted automatically, use the
+ * {@link #deleteOnExit} method.
+ *
+ * prefix argument must be at least three characters
+ * long. It is recommended that the prefix be a short, meaningful string
+ * such as "hjb" or "mail". The
+ * suffix argument may be null, in which case the
+ * suffix ".tmp" will be used.
+ *
+ * '.') then the period and the first three characters
+ * following it will always be preserved. Once these adjustments have been
+ * made the name of the new file will be generated by concatenating the
+ * prefix, five or more internally-generated characters, and the suffix.
+ *
+ * directory argument is null then the
+ * system-dependent default temporary-file directory will be used. The
+ * default temporary-file directory is specified by the system property
+ * java.io.tmpdir. On UNIX systems the default value of this
+ * property is typically "/tmp" or "/var/tmp"; on
+ * Microsoft Windows systems it is typically "C:\\WINNT\\TEMP". A different
+ * value may be given to this system property when the Java virtual machine
+ * is invoked, but programmatic changes to this property are not guaranteed
+ * to have any effect upon the temporary directory used by this method.
+ *
+ * @param prefix The prefix string to be used in generating the file's
+ * name; must be at least three characters long
+ *
+ * @param suffix The suffix string to be used in generating the file's
+ * name; may be null, in which case the
+ * suffix ".tmp" will be used
+ *
+ * @param directory The directory in which the file is to be created, or
+ * null if the default temporary-file
+ * directory is to be used
+ *
+ * @return An abstract pathname denoting a newly-created empty file
+ *
+ * @throws IllegalArgumentException
+ * If the prefix argument contains fewer than three
+ * characters
+ *
+ * @throws IOException If a file could not be created
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method does not allow a file to be created
+ *
+ * @since 1.2
+ */
+ public static File createTempFile(String prefix, String suffix,
+ File directory)
+ throws IOException
+ {
+ if (prefix.length() < 3)
+ throw new IllegalArgumentException("Prefix string too short");
+ if (suffix == null)
+ suffix = ".tmp";
+
+ File tmpdir = (directory != null) ? directory : TempDirectory.location();
+ SecurityManager sm = System.getSecurityManager();
+ File f;
+ do {
+ f = TempDirectory.generateFile(prefix, suffix, tmpdir);
+ if (sm != null) {
+ try {
+ sm.checkWrite(f.getPath());
+ } catch (SecurityException se) {
+ // don't reveal temporary directory location
+ if (directory == null)
+ throw new SecurityException("Unable to create temporary file");
+ throw se;
+ }
+ }
+ } while (!fs.createFileExclusively(f.getPath()));
+ return f;
+ }
+
+ /**
+ * Creates an empty file in the default temporary-file directory, using
+ * the given prefix and suffix to generate its name. Invoking this method
+ * is equivalent to invoking {@link #createTempFile(java.lang.String,
+ * java.lang.String, java.io.File)
+ * createTempFile(prefix, suffix, null)}.
+ *
+ * null, in which case the
+ * suffix ".tmp" will be used
+ *
+ * @return An abstract pathname denoting a newly-created empty file
+ *
+ * @throws IllegalArgumentException
+ * If the prefix argument contains fewer than three
+ * characters
+ *
+ * @throws IOException If a file could not be created
+ *
+ * @throws SecurityException
+ * If a security manager exists and its {@link
+ * java.lang.SecurityManager#checkWrite(java.lang.String)}
+ * method does not allow a file to be created
+ *
+ * @since 1.2
+ * @see java.nio.file.Files#createTempDirectory(String,FileAttribute[])
+ */
+ public static File createTempFile(String prefix, String suffix)
+ throws IOException
+ {
+ return createTempFile(prefix, suffix, null);
+ }
+
+ /* -- Basic infrastructure -- */
+
+ /**
+ * Compares two abstract pathnames lexicographically. The ordering
+ * defined by this method depends upon the underlying system. On UNIX
+ * systems, alphabetic case is significant in comparing pathnames; on Microsoft Windows
+ * systems it is not.
+ *
+ * @param pathname The abstract pathname to be compared to this abstract
+ * pathname
+ *
+ * @return Zero if the argument is equal to this abstract pathname, a
+ * value less than zero if this abstract pathname is
+ * lexicographically less than the argument, or a value greater
+ * than zero if this abstract pathname is lexicographically
+ * greater than the argument
+ *
+ * @since 1.2
+ */
+ public int compareTo(File pathname) {
+ return fs.compare(this, pathname);
+ }
+
+ /**
+ * Tests this abstract pathname for equality with the given object.
+ * Returns true if and only if the argument is not
+ * null and is an abstract pathname that denotes the same file
+ * or directory as this abstract pathname. Whether or not two abstract
+ * pathnames are equal depends upon the underlying system. On UNIX
+ * systems, alphabetic case is significant in comparing pathnames; on Microsoft Windows
+ * systems it is not.
+ *
+ * @param obj The object to be compared with this abstract pathname
+ *
+ * @return true if and only if the objects are the same;
+ * false otherwise
+ */
+ public boolean equals(Object obj) {
+ if ((obj != null) && (obj instanceof File)) {
+ return compareTo((File)obj) == 0;
+ }
+ return false;
+ }
+
+ /**
+ * Computes a hash code for this abstract pathname. Because equality of
+ * abstract pathnames is inherently system-dependent, so is the computation
+ * of their hash codes. On UNIX systems, the hash code of an abstract
+ * pathname is equal to the exclusive or of the hash code
+ * of its pathname string and the decimal value
+ * 1234321. On Microsoft Windows systems, the hash
+ * code is equal to the exclusive or of the hash code of
+ * its pathname string converted to lower case and the decimal
+ * value 1234321. Locale is not taken into account on
+ * lowercasing the pathname string.
+ *
+ * @return A hash code for this abstract pathname
+ */
+ public int hashCode() {
+ return fs.hashCode(this);
+ }
+
+ /**
+ * Returns the pathname string of this abstract pathname. This is just the
+ * string returned by the {@link #getPath} method.
+ *
+ * @return The string form of this abstract pathname
+ */
+ public String toString() {
+ return getPath();
+ }
+
+ /**
+ * WriteObject is called to save this filename.
+ * The separator character is saved also so it can be replaced
+ * in case the path is reconstituted on a different host type.
+ *
+ * Subsequent invocations of this method return the same {@code Path}.
+ *
+ *
+ * {@link java.nio.file.FileSystems#getDefault FileSystems.getDefault}().{@link
+ * java.nio.file.FileSystem#getPath getPath}(this.{@link #getPath getPath}());
+ *