Also see:

java.lang.System#getProperty(java.lang.String)

Also see:

java.lang.System#getProperty(java.lang.String)

 public File(String pathname) 
{
        if (pathname == null) {
            throw new NullPointerException();
        }
        this.path = fs.normalize(pathname);
        this.prefixLength = fs.prefixLength(this.path);
}

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.

Parameters:

pathname - A pathname string

Throws:

NullPointerException - If the pathname argument is null

 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);
}

Creates a new File instance by converting the given file: URI into an abstract pathname.

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

new File( f.toURI ()).equals( f.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.

Parameters:

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

IllegalArgumentException - If the preconditions on the parameter do not hold

Also see:

toURI()
java.net.URI
since: 1.4 -

 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 pathname string and a child pathname string.

If 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.

Otherwise the 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.

Parameters:

parent - The parent pathname string

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 from a parent abstract pathname and a child pathname string.

If 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.

Otherwise the 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.

Parameters:

parent - The parent abstract pathname

child - The child pathname string

Throws:

NullPointerException - If child is null

 public boolean canExecute() 
{
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkExec(path);
        }
        return fs.checkAccess(this, FileSystem.ACCESS_EXECUTE);
}

Tests whether the application can execute the file denoted by this abstract pathname.

 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 read the file denoted by this abstract pathname.

 public boolean canWrite() 
{
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkWrite(path);
        }
        return fs.checkAccess(this, FileSystem.ACCESS_WRITE);
}

Tests whether the application can modify the file denoted by this abstract pathname.

 public int compareTo(File pathname) 
{
        return fs.compare(this, pathname);
}

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.

 public boolean createNewFile() throws IOException 
{
        SecurityManager security = System.getSecurityManager();
        if (security != null) security.checkWrite(path);
        return fs.createFileExclusively(path);
}

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.

Note: this method should not be used for file-locking, as the resulting protocol cannot be made to work reliably. The FileLock facility should be used instead.

 public static File createTempFile(String prefix,
    String suffix) throws IOException 
{
        return createTempFile(prefix, suffix, null);
}

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 java.lang.String, java.io.File) createTempFile(prefix, suffix, null) .

The 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.

 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 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:

1. The file denoted by the returned abstract pathname did not exist before this method was invoked, and
2. Neither this method nor any of its variants will return the same abstract pathname again in the current invocation of the virtual machine.
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 #deleteOnExit method.

The 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.

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 ('.') 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.

If the 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.

 public boolean delete() 
{
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkDelete(path);
        }
        return fs.delete(this);
}

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.

Note that the java.nio.file.Files class defines the delete method to throw an IOException when a file cannot be deleted. This is useful for error reporting and to diagnose why a file cannot be deleted.

 public  void deleteOnExit() 
{
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkDelete(path);
        }
        DeleteOnExitHook.add(path);
}

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.

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 FileLock facility should be used instead.

 public boolean equals(Object obj) 
{
        if ((obj != null) && (obj instanceof File)) {
            return compareTo((File)obj) == 0;
        }
        return false;
}

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.

 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 or directory denoted by this abstract pathname exists.

 public File getAbsoluteFile() 
{
        String absPath = getAbsolutePath();
        return new File(absPath, fs.prefixLength(absPath));
}

Returns the absolute form of this abstract pathname. Equivalent to new File(this.#getAbsolutePath ).

 public String getAbsolutePath() 
{
        return fs.resolve(this);
}

Returns the absolute pathname string of this abstract pathname.

If this abstract pathname is already absolute, then the pathname string is simply returned as if by the #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.

 public File getCanonicalFile() throws IOException 
{
        String canonPath = getCanonicalPath();
        return new File(canonPath, fs.prefixLength(canonPath));
}

Returns the canonical form of this abstract pathname. Equivalent to new File(this.#getCanonicalPath ).

 public String getCanonicalPath() throws IOException 
{
        return fs.canonicalize(fs.resolve(this));
}

Returns the canonical pathname string of this abstract pathname.

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 #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.

 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 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.

 public String getName() 
{
        int index = path.lastIndexOf(separatorChar);
        if (index <  prefixLength) return path.substring(prefixLength);
        return path.substring(index + 1);
}

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.

 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 pathname string of this abstract pathname's parent, or null if this pathname does not name a parent directory.

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.

 public File getParentFile() 
{
        String p = this.getParent();
        if (p == null) return null;
        return new File(p, this.prefixLength);
}

Returns the abstract pathname of this abstract pathname's parent, or null if this pathname does not name a parent directory.

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.

 public String getPath() 
{
        return path;
}

Converts this abstract pathname into a pathname string. The resulting string uses the default name-separator character to separate the names in the name sequence.

 int getPrefixLength() 
{
        return prefixLength;
}

Returns the length of this abstract pathname's prefix. For use by FileSystem classes.

 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 size of the partition named by this abstract pathname.

 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);
}

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 #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.

 public int hashCode() 
{
        return fs.hashCode(this);
}

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.

 public boolean isAbsolute() 
{
        return fs.isAbsolute(this);
}

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 "\\\\".

 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 directory.

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 Files.readAttributes method may be used.

 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 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.

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 Files.readAttributes method may be used.

 public boolean isHidden() 
{
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkRead(path);
        }
        return ((fs.getBooleanAttributes(this) & FileSystem.BA_HIDDEN) != 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.

 public long lastModified() 
{
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkRead(path);
        }
        return fs.getLastModifiedTime(this);
}

Returns the time that the file denoted by this abstract pathname was last modified.

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 Files.readAttributes method may be used.

 public long length() 
{
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkRead(path);
        }
        return fs.getLength(this);
}

Returns the length of the file denoted by this abstract pathname. The return value is unspecified if this pathname denotes a directory.

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 Files.readAttributes method may be used.

 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.

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 java.nio.file.Files class defines the 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.

 public String[] list(FilenameFilter filter) 
{
        String names[] = list();
        if ((names == null) || (filter == null)) {
            return names;
        }
        List< String > v = new ArrayList<  >();
        for (int i = 0 ; i <  names.length ; i++) {
            if (filter.accept(this, names[i])) {
                v.add(names[i]);
            }
        }
        return v.toArray(new String[v.size()]);
}

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 #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 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.

 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 in the directory denoted by this abstract pathname.

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 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 java.nio.file.Files class defines the 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.

 public File[] listFiles(FilenameFilter filter) 
{
        String ss[] = list();
        if (ss == null) return null;
        ArrayList< File > files = new ArrayList<  >();
        for (String s : ss)
            if ((filter == null) || filter.accept(this, s))
                files.add(new File(s, this));
        return files.toArray(new File[files.size()]);
}

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 #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 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.

 public File[] listFiles(FileFilter filter) 
{
        String ss[] = list();
        if (ss == null) return null;
        ArrayList< File > files = new ArrayList<  >();
        for (String s : ss) {
            File f = new File(s, this);
            if ((filter == null) || filter.accept(f))
                files.add(f);
        }
        return files.toArray(new File[files.size()]);
}

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 #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 FileFilter.accept(File) method of the filter is invoked on the pathname.

 public static File[] listRoots() 
{
        return fs.listRoots();
}

List the available filesystem roots.

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 SecurityManager#checkRead(String) method denies read access to a particular root directory, then that directory will not appear in the result.

 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.

 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());
}

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.

 public boolean renameTo(File dest) 
{
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkWrite(path);
            security.checkWrite(dest.path);
        }
        return fs.rename(this, dest);
}

Renames the file denoted by this abstract pathname.

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 java.nio.file.Files class defines the move method to move or rename a file in a platform independent manner.

 public boolean setExecutable(boolean executable) 
{
        return setExecutable(executable, true);
}

A convenience method to set the owner's execute permission for this abstract pathname.

An invocation of this method of the form file.setExcutable(arg) behaves in exactly the same way as the invocation

    file.setExecutable(arg, true) 

 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);
}

Sets the owner's or everybody's execute permission for this abstract pathname.

The 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.

 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);
}

Sets the last-modified time of the file or directory named by this abstract pathname.

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 #lastModified method will return the (possibly truncated) time argument that was passed to this method.

 public boolean setReadOnly() 
{
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkWrite(path);
        }
        return fs.setReadOnly(this);
}

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.

 public boolean setReadable(boolean readable) 
{
        return setReadable(readable, true);
}

A convenience method to set the owner's read permission for this abstract pathname.

An invocation of this method of the form file.setReadable(arg) behaves in exactly the same way as the invocation

    file.setReadable(arg, true) 

 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);
}

Sets the owner's or everybody's read permission for this abstract pathname.

The 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.

 public boolean setWritable(boolean writable) 
{
        return setWritable(writable, true);
}

A convenience method to set the owner's write permission for this abstract pathname.

An invocation of this method of the form file.setWritable(arg) behaves in exactly the same way as the invocation

    file.setWritable(arg, true) 

 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);
}

Sets the owner's or everybody's write permission for this abstract pathname.

The 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.

 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;
}

Returns a java.nio.file.Path object constructed from the this abstract path. The resulting {@code Path} is associated with the default-filesystem .

The first invocation of this method works as if invoking it were equivalent to evaluating the expression:

 FileSystems.getDefault (). getPath (this. getPath ());

Subsequent invocations of this method return the same {@code Path}.

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.

 public String toString() 
{
        return getPath();
}

Returns the pathname string of this abstract pathname. This is just the string returned by the #getPath method.

 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
        }
}

Constructs a file: URI that represents this abstract pathname.

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

new File ( f.toURI()).equals( f.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.

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 Path class defines the toUri method to encode the server name in the authority component of the resulting {@code URI}. The toPath method may be used to obtain a {@code Path} representing this abstract pathname.

 public URL toURL() throws MalformedURLException 
{
        return new URL("file", "", slashify(getAbsolutePath(), isDirectory()));
}

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.