java.io
Class File

java.lang.Object sample code for java.lang.Object definition code for java.lang.Object 
  extended by java.io.File
All Implemented Interfaces:
Serializable sample code for java.io.Serializable definition code for java.io.Serializable , Comparable sample code for java.lang.Comparable definition code for java.lang.Comparable <File sample code for java.io.File definition code for java.io.File >

public class File
extends Object sample code for java.lang.Object definition code for java.lang.Object
implements Serializable sample code for java.io.Serializable definition code for java.io.Serializable , Comparable sample code for java.lang.Comparable definition code for java.lang.Comparable <File sample code for java.io.File definition code for java.io.File >

An abstract representation of file and directory pathnames.

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:

  1. An optional system-dependent prefix string, such as a disk-drive specifier, "/" for the UNIX root directory, or "\\\\" for a Microsoft Windows UNC pathname, and
  2. A sequence of zero or more string names.
Each name in an abstract pathname except for the last denotes a directory; the last name may denote either a directory or a file. The empty abstract pathname has no prefix and an empty name sequence.

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 separator sample code for java.io.File.separator definition code for java.io.File.separator and separatorChar sample code for java.io.File.separatorChar definition code for java.io.File.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 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:

Instances of the File class are immutable; that is, once created, the abstract pathname represented by a File object will never change.

Since:
JDK1.0
See Also:
Serialized Form

Field Summary
static String sample code for java.lang.String definition code for java.lang.String pathSeparator sample code for java.io.File.pathSeparator definition code for java.io.File.pathSeparator
          The system-dependent path-separator character, represented as a string for convenience.
static char pathSeparatorChar sample code for java.io.File.pathSeparatorChar definition code for java.io.File.pathSeparatorChar
          The system-dependent path-separator character.
static String sample code for java.lang.String definition code for java.lang.String separator sample code for java.io.File.separator definition code for java.io.File.separator
          The system-dependent default name-separator character, represented as a string for convenience.
static char separatorChar sample code for java.io.File.separatorChar definition code for java.io.File.separatorChar
          The system-dependent default name-separator character.
 
Constructor Summary
File sample code for java.io.File.File(java.io.File, java.lang.String) definition code for java.io.File.File(java.io.File, java.lang.String) (File sample code for java.io.File definition code for java.io.File  parent, String sample code for java.lang.String definition code for java.lang.String  child)
          Creates a new File instance from a parent abstract pathname and a child pathname string.
File sample code for java.io.File.File(java.lang.String) definition code for java.io.File.File(java.lang.String) (String sample code for java.lang.String definition code for java.lang.String  pathname)
          Creates a new File instance by converting the given pathname string into an abstract pathname.
File sample code for java.io.File.File(java.lang.String, java.lang.String) definition code for java.io.File.File(java.lang.String, java.lang.String) (String sample code for java.lang.String definition code for java.lang.String  parent, String sample code for java.lang.String definition code for java.lang.String  child)
          Creates a new File instance from a parent pathname string and a child pathname string.
File sample code for java.io.File.File(java.net.URI) definition code for java.io.File.File(java.net.URI) (URI sample code for java.net.URI definition code for java.net.URI  uri)
          Creates a new File instance by converting the given file: URI into an abstract pathname.
 
Method Summary
 boolean canRead sample code for java.io.File.canRead() definition code for java.io.File.canRead() ()
          Tests whether the application can read the file denoted by this abstract pathname.
 boolean canWrite sample code for java.io.File.canWrite() definition code for java.io.File.canWrite() ()
          Tests whether the application can modify the file denoted by this abstract pathname.
 int compareTo sample code for java.io.File.compareTo(java.io.File) definition code for java.io.File.compareTo(java.io.File) (File sample code for java.io.File definition code for java.io.File  pathname)
          Compares two abstract pathnames lexicographically.
 boolean createNewFile sample code for java.io.File.createNewFile() definition code for java.io.File.createNewFile() ()
          Atomically creates a new, empty file named by this abstract pathname if and only if a file with this name does not yet exist.
static File sample code for java.io.File definition code for java.io.File createTempFile sample code for java.io.File.createTempFile(java.lang.String, java.lang.String) definition code for java.io.File.createTempFile(java.lang.String, java.lang.String) (String sample code for java.lang.String definition code for java.lang.String  prefix, String sample code for java.lang.String definition code for java.lang.String  suffix)
          Creates an empty file in the default temporary-file directory, using the given prefix and suffix to generate its name.
static File sample code for java.io.File definition code for java.io.File createTempFile sample code for java.io.File.createTempFile(java.lang.String, java.lang.String, java.io.File) definition code for java.io.File.createTempFile(java.lang.String, java.lang.String, java.io.File) (String sample code for java.lang.String definition code for java.lang.String  prefix, String sample code for java.lang.String definition code for java.lang.String  suffix, File sample code for java.io.File definition code for java.io.File  directory)
           Creates a new empty file in the specified directory, using the given prefix and suffix strings to generate its name.
 boolean delete sample code for java.io.File.delete() definition code for java.io.File.delete() ()
          Deletes the file or directory denoted by this abstract pathname.
 void deleteOnExit sample code for java.io.File.deleteOnExit() definition code for java.io.File.deleteOnExit() ()
          Requests that the file or directory denoted by this abstract pathname be deleted when the virtual machine terminates.
 boolean equals sample code for java.io.File.equals(java.lang.Object) definition code for java.io.File.equals(java.lang.Object) (Object sample code for java.lang.Object definition code for java.lang.Object  obj)
          Tests this abstract pathname for equality with the given object.
 boolean exists sample code for java.io.File.exists() definition code for java.io.File.exists() ()
          Tests whether the file or directory denoted by this abstract pathname exists.
 File sample code for java.io.File definition code for java.io.File getAbsoluteFile sample code for java.io.File.getAbsoluteFile() definition code for java.io.File.getAbsoluteFile() ()
          Returns the absolute form of this abstract pathname.
 String sample code for java.lang.String definition code for java.lang.String getAbsolutePath sample code for java.io.File.getAbsolutePath() definition code for java.io.File.getAbsolutePath() ()
          Returns the absolute pathname string of this abstract pathname.
 File sample code for java.io.File definition code for java.io.File getCanonicalFile sample code for java.io.File.getCanonicalFile() definition code for java.io.File.getCanonicalFile() ()
          Returns the canonical form of this abstract pathname.
 String sample code for java.lang.String definition code for java.lang.String getCanonicalPath sample code for java.io.File.getCanonicalPath() definition code for java.io.File.getCanonicalPath() ()
          Returns the canonical pathname string of this abstract pathname.
 String sample code for java.lang.String definition code for java.lang.String getName sample code for java.io.File.getName() definition code for java.io.File.getName() ()
          Returns the name of the file or directory denoted by this abstract pathname.
 String sample code for java.lang.String definition code for java.lang.String getParent sample code for java.io.File.getParent() definition code for java.io.File.getParent() ()
          Returns the pathname string of this abstract pathname's parent, or null if this pathname does not name a parent directory.
 File sample code for java.io.File definition code for java.io.File getParentFile sample code for java.io.File.getParentFile() definition code for java.io.File.getParentFile() ()
          Returns the abstract pathname of this abstract pathname's parent, or null if this pathname does not name a parent directory.
 String sample code for java.lang.String definition code for java.lang.String getPath sample code for java.io.File.getPath() definition code for java.io.File.getPath() ()
          Converts this abstract pathname into a pathname string.
 int hashCode sample code for java.io.File.hashCode() definition code for java.io.File.hashCode() ()
          Computes a hash code for this abstract pathname.
 boolean isAbsolute sample code for java.io.File.isAbsolute() definition code for java.io.File.isAbsolute() ()
          Tests whether this abstract pathname is absolute.
 boolean isDirectory sample code for java.io.File.isDirectory() definition code for java.io.File.isDirectory() ()
          Tests whether the file denoted by this abstract pathname is a directory.
 boolean isFile sample code for java.io.File.isFile() definition code for java.io.File.isFile() ()
          Tests whether the file denoted by this abstract pathname is a normal file.
 boolean isHidden sample code for java.io.File.isHidden() definition code for java.io.File.isHidden() ()
          Tests whether the file named by this abstract pathname is a hidden file.
 long lastModified sample code for java.io.File.lastModified() definition code for java.io.File.lastModified() ()
          Returns the time that the file denoted by this abstract pathname was last modified.
 long length sample code for java.io.File.length() definition code for java.io.File.length() ()
          Returns the length of the file denoted by this abstract pathname.
 String sample code for java.lang.String definition code for java.lang.String [] list sample code for java.io.File.list() definition code for java.io.File.list() ()
          Returns an array of strings naming the files and directories in the directory denoted by this abstract pathname.
 String sample code for java.lang.String definition code for java.lang.String [] list sample code for java.io.File.list(java.io.FilenameFilter) definition code for java.io.File.list(java.io.FilenameFilter) (FilenameFilter sample code for java.io.FilenameFilter definition code for java.io.FilenameFilter  filter)
          Returns an array of strings naming the files and directories in the directory denoted by this abstract pathname that satisfy the specified filter.
 File sample code for java.io.File definition code for java.io.File [] listFiles sample code for java.io.File.listFiles() definition code for java.io.File.listFiles() ()
          Returns an array of abstract pathnames denoting the files in the directory denoted by this abstract pathname.
 File sample code for java.io.File definition code for java.io.File [] listFiles sample code for java.io.File.listFiles(java.io.FileFilter) definition code for java.io.File.listFiles(java.io.FileFilter) (FileFilter sample code for java.io.FileFilter definition code for java.io.FileFilter  filter)
          Returns an array of abstract pathnames denoting the files and directories in the directory denoted by this abstract pathname that satisfy the specified filter.
 File sample code for java.io.File definition code for java.io.File [] listFiles sample code for java.io.File.listFiles(java.io.FilenameFilter) definition code for java.io.File.listFiles(java.io.FilenameFilter) (FilenameFilter sample code for java.io.FilenameFilter definition code for java.io.FilenameFilter  filter)
          Returns an array of abstract pathnames denoting the files and directories in the directory denoted by this abstract pathname that satisfy the specified filter.
static File sample code for java.io.File definition code for java.io.File [] listRoots sample code for java.io.File.listRoots() definition code for java.io.File.listRoots() ()
          List the available filesystem roots.
 boolean mkdir sample code for java.io.File.mkdir() definition code for java.io.File.mkdir() ()
          Creates the directory named by this abstract pathname.
 boolean mkdirs sample code for java.io.File.mkdirs() definition code for java.io.File.mkdirs() ()
          Creates the directory named by this abstract pathname, including any necessary but nonexistent parent directories.
 boolean renameTo sample code for java.io.File.renameTo(java.io.File) definition code for java.io.File.renameTo(java.io.File) (File sample code for java.io.File definition code for java.io.File  dest)
          Renames the file denoted by this abstract pathname.
 boolean setLastModified sample code for java.io.File.setLastModified(long) definition code for java.io.File.setLastModified(long) (long time)
          Sets the last-modified time of the file or directory named by this abstract pathname.
 boolean setReadOnly sample code for java.io.File.setReadOnly() definition code for java.io.File.setReadOnly() ()
          Marks the file or directory named by this abstract pathname so that only read operations are allowed.
 String sample code for java.lang.String definition code for java.lang.String toString sample code for java.io.File.toString() definition code for java.io.File.toString() ()
          Returns the pathname string of this abstract pathname.
 URI sample code for java.net.URI definition code for java.net.URI toURI sample code for java.io.File.toURI() definition code for java.io.File.toURI() ()
          Constructs a file: URI that represents this abstract pathname.
 URL sample code for java.net.URL definition code for java.net.URL toURL sample code for java.io.File.toURL() definition code for java.io.File.toURL() ()
          Converts this abstract pathname into a file: URL.
 
Methods inherited from class java.lang.Object sample code for java.lang.Object definition code for java.lang.Object
clone sample code for java.lang.Object.clone() definition code for java.lang.Object.clone() , finalize sample code for java.lang.Object.finalize() definition code for java.lang.Object.finalize() , getClass sample code for java.lang.Object.getClass() definition code for java.lang.Object.getClass() , notify sample code for java.lang.Object.notify() definition code for java.lang.Object.notify() , notifyAll sample code for java.lang.Object.notifyAll() definition code for java.lang.Object.notifyAll() , wait sample code for java.lang.Object.wait() definition code for java.lang.Object.wait() , wait sample code for java.lang.Object.wait(long) definition code for java.lang.Object.wait(long) , wait sample code for java.lang.Object.wait(long, int) definition code for java.lang.Object.wait(long, int)
 

Field Detail

separatorChar sample code for java.io.File.separatorChar

public static final char separatorChar
The system-dependent default name-separator character. This field is initialized to contain the first character of the value of the system property file.separator. On UNIX systems the value of this field is '/'; on Microsoft Windows systems it is '\\'.

See Also:
System.getProperty(java.lang.String) sample code for java.lang.System.getProperty(java.lang.String) definition code for java.lang.System.getProperty(java.lang.String)

separator sample code for java.io.File.separator

public static final String sample code for java.lang.String definition code for java.lang.String  separator
The system-dependent default name-separator character, represented as a string for convenience. This string contains a single character, namely separatorChar sample code for java.io.File.separatorChar definition code for java.io.File.separatorChar .


pathSeparatorChar sample code for java.io.File.pathSeparatorChar

public static final char pathSeparatorChar
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 Also:
System.getProperty(java.lang.String) sample code for java.lang.System.getProperty(java.lang.String) definition code for java.lang.System.getProperty(java.lang.String)

pathSeparator sample code for java.io.File.pathSeparator

public static final String sample code for java.lang.String definition code for java.lang.String  pathSeparator
The system-dependent path-separator character, represented as a string for convenience. This string contains a single character, namely pathSeparatorChar sample code for java.io.File.pathSeparatorChar definition code for java.io.File.pathSeparatorChar .

Constructor Detail

File sample code for java.io.File(java.lang.String) definition code for java.io.File(java.lang.String)

public File(String sample code for java.lang.String definition code for java.lang.String  pathname)
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 sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - If the pathname argument is null

File sample code for java.io.File(java.lang.String, java.lang.String) definition code for java.io.File(java.lang.String, java.lang.String)

public File(String sample code for java.lang.String definition code for java.lang.String  parent,
            String sample code for java.lang.String definition code for java.lang.String  child)
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 sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - If child is null

File sample code for java.io.File(java.io.File, java.lang.String) definition code for java.io.File(java.io.File, java.lang.String)

public File(File sample code for java.io.File definition code for java.io.File  parent,
            String sample code for java.lang.String definition code for java.lang.String  child)
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 sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - If child is null

File sample code for java.io.File(java.net.URI) definition code for java.io.File(java.net.URI)

public File(URI sample code for java.net.URI definition code for java.net.URI  uri)
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 sample code for java.io.File.toURI() definition code for java.io.File.toURI() ()).equals( f.getAbsoluteFile sample code for java.io.File.getAbsoluteFile() definition code for java.io.File.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 sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - If uri is null
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - If the preconditions on the parameter do not hold
Since:
1.4
See Also:
toURI() sample code for java.io.File.toURI() definition code for java.io.File.toURI() , URI sample code for java.net.URI definition code for java.net.URI
Method Detail

getName sample code for java.io.File.getName() definition code for java.io.File.getName()

public String sample code for java.lang.String definition code for java.lang.String  getName()
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.

Returns:
The name of the file or directory denoted by this abstract pathname, or the empty string if this pathname's name sequence is empty

getParent sample code for java.io.File.getParent() definition code for java.io.File.getParent()

public String sample code for java.lang.String definition code for java.lang.String  getParent()
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.

Returns:
The pathname string of the parent directory named by this abstract pathname, or null if this pathname does not name a parent

getParentFile sample code for java.io.File.getParentFile() definition code for java.io.File.getParentFile()

public File sample code for java.io.File definition code for java.io.File  getParentFile()
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.

Returns:
The abstract pathname of the parent directory named by this abstract pathname, or null if this pathname does not name a parent
Since:
1.2

getPath sample code for java.io.File.getPath() definition code for java.io.File.getPath()

public String sample code for java.lang.String definition code for java.lang.String  getPath()
Converts this abstract pathname into a pathname string. The resulting string uses the default name-separator character sample code for java.io.File.separator definition code for java.io.File.separator to separate the names in the name sequence.

Returns:
The string form of this abstract pathname

isAbsolute sample code for java.io.File.isAbsolute() definition code for java.io.File.isAbsolute()

public boolean isAbsolute()
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 "\\\\".

Returns:
true if this abstract pathname is absolute, false otherwise

getAbsolutePath sample code for java.io.File.getAbsolutePath() definition code for java.io.File.getAbsolutePath()

public String sample code for java.lang.String definition code for java.lang.String  getAbsolutePath()
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() sample code for java.io.File.getPath() definition code for java.io.File.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.

Returns:
The absolute pathname string denoting the same file or directory as this abstract pathname
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a required system property value cannot be accessed.
See Also:
isAbsolute() sample code for java.io.File.isAbsolute() definition code for java.io.File.isAbsolute()

getAbsoluteFile sample code for java.io.File.getAbsoluteFile() definition code for java.io.File.getAbsoluteFile()

public File sample code for java.io.File definition code for java.io.File  getAbsoluteFile()
Returns the absolute form of this abstract pathname. Equivalent to new File(this.getAbsolutePath() sample code for java.io.File.getAbsolutePath() definition code for java.io.File.getAbsolutePath() ()).

Returns:
The absolute abstract pathname denoting the same file or directory as this abstract pathname
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a required system property value cannot be accessed.
Since:
1.2

getCanonicalPath sample code for java.io.File.getCanonicalPath() definition code for java.io.File.getCanonicalPath()

public String sample code for java.lang.String definition code for java.lang.String  getCanonicalPath()
                        throws IOException sample code for java.io.IOException definition code for java.io.IOException 
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() sample code for java.io.File.getAbsolutePath() definition code for java.io.File.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.

Returns:
The canonical pathname string denoting the same file or directory as this abstract pathname
Throws:
IOException sample code for java.io.IOException definition code for java.io.IOException - If an I/O error occurs, which is possible because the construction of the canonical pathname may require filesystem queries
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a required system property value cannot be accessed, or if a security manager exists and its SecurityManager.checkRead(java.io.FileDescriptor) sample code for java.lang.SecurityManager.checkRead(java.io.FileDescriptor) definition code for java.lang.SecurityManager.checkRead(java.io.FileDescriptor) method denies read access to the file
Since:
JDK1.1

getCanonicalFile sample code for java.io.File.getCanonicalFile() definition code for java.io.File.getCanonicalFile()

public File sample code for java.io.File definition code for java.io.File  getCanonicalFile()
                      throws IOException sample code for java.io.IOException definition code for java.io.IOException 
Returns the canonical form of this abstract pathname. Equivalent to new File(this.getCanonicalPath() sample code for java.io.File.getCanonicalPath() definition code for java.io.File.getCanonicalPath() ()).

Returns:
The canonical pathname string denoting the same file or directory as this abstract pathname
Throws:
IOException sample code for java.io.IOException definition code for java.io.IOException - If an I/O error occurs, which is possible because the construction of the canonical pathname may require filesystem queries
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a required system property value cannot be accessed, or if a security manager exists and its SecurityManager.checkRead(java.io.FileDescriptor) sample code for java.lang.SecurityManager.checkRead(java.io.FileDescriptor) definition code for java.lang.SecurityManager.checkRead(java.io.FileDescriptor) method denies read access to the file
Since:
1.2

toURL sample code for java.io.File.toURL() definition code for java.io.File.toURL()

public URL sample code for java.net.URL definition code for java.net.URL  toURL()
          throws MalformedURLException sample code for java.net.MalformedURLException definition code for java.net.MalformedURLException 
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.

Usage note: 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 toURI sample code for java.io.File.toURI() definition code for java.io.File.toURI() method, and then converting the URI into a URL via the URI.toURL sample code for java.net.URI.toURL() definition code for java.net.URI.toURL() method.

Returns:
A URL object representing the equivalent file URL
Throws:
MalformedURLException sample code for java.net.MalformedURLException definition code for java.net.MalformedURLException - If the path cannot be parsed as a URL
Since:
1.2
See Also:
toURI() sample code for java.io.File.toURI() definition code for java.io.File.toURI() , URI sample code for java.net.URI definition code for java.net.URI , URI.toURL() sample code for java.net.URI.toURL() definition code for java.net.URI.toURL() , URL sample code for java.net.URL definition code for java.net.URL

toURI sample code for java.io.File.toURI() definition code for java.io.File.toURI()

public URI sample code for java.net.URI definition code for java.net.URI  toURI()
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 sample code for java.io.File.File(java.net.URI) definition code for java.io.File.File(java.net.URI) ( f.toURI()).equals( f.getAbsoluteFile sample code for java.io.File.getAbsoluteFile() definition code for java.io.File.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.

Returns:
An absolute, hierarchical URI with a scheme equal to "file", a path representing this abstract pathname, and undefined authority, query, and fragment components
Since:
1.4
See Also:
File(java.net.URI) sample code for java.io.File.File(java.net.URI) definition code for java.io.File.File(java.net.URI) , URI sample code for java.net.URI definition code for java.net.URI , URI.toURL() sample code for java.net.URI.toURL() definition code for java.net.URI.toURL()

canRead sample code for java.io.File.canRead() definition code for java.io.File.canRead()

public boolean canRead()
Tests whether the application can read the file denoted by this abstract pathname.

Returns:
true if and only if the file specified by this abstract pathname exists and can be read by the application; false otherwise
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the file

canWrite sample code for java.io.File.canWrite() definition code for java.io.File.canWrite()

public boolean canWrite()
Tests whether the application can modify the file denoted by this abstract pathname.

Returns:
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 sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkWrite(java.lang.String) sample code for java.lang.SecurityManager.checkWrite(java.lang.String) definition code for java.lang.SecurityManager.checkWrite(java.lang.String) method denies write access to the file

exists sample code for java.io.File.exists() definition code for java.io.File.exists()

public boolean exists()
Tests whether the file or directory denoted by this abstract pathname exists.

Returns:
true if and only if the file or directory denoted by this abstract pathname exists; false otherwise
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the file or directory

isDirectory sample code for java.io.File.isDirectory() definition code for java.io.File.isDirectory()

public boolean isDirectory()
Tests whether the file denoted by this abstract pathname is a directory.

Returns:
true if and only if the file denoted by this abstract pathname exists and is a directory; false otherwise
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the file

isFile sample code for java.io.File.isFile() definition code for java.io.File.isFile()

public boolean isFile()
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.

Returns:
true if and only if the file denoted by this abstract pathname exists and is a normal file; false otherwise
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the file

isHidden sample code for java.io.File.isHidden() definition code for java.io.File.isHidden()

public boolean isHidden()
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.

Returns:
true if and only if the file denoted by this abstract pathname is hidden according to the conventions of the underlying platform
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the file
Since:
1.2

lastModified sample code for java.io.File.lastModified() definition code for java.io.File.lastModified()

public long lastModified()
Returns the time that the file denoted by this abstract pathname was last modified.

Returns:
A 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 sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the file

length sample code for java.io.File.length() definition code for java.io.File.length()

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

Returns:
The length, in bytes, of the file denoted by this abstract pathname, or 0L if the file does not exist
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the file

createNewFile sample code for java.io.File.createNewFile() definition code for java.io.File.createNewFile()

public boolean createNewFile()
                      throws IOException sample code for java.io.IOException definition code for java.io.IOException 
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 sample code for java.nio.channels.FileLock definition code for java.nio.channels.FileLock facility should be used instead.

Returns:
true if the named file does not exist and was successfully created; false if the named file already exists
Throws:
IOException sample code for java.io.IOException definition code for java.io.IOException - If an I/O error occurred
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkWrite(java.lang.String) sample code for java.lang.SecurityManager.checkWrite(java.lang.String) definition code for java.lang.SecurityManager.checkWrite(java.lang.String) method denies write access to the file
Since:
1.2

delete sample code for java.io.File.delete() definition code for java.io.File.delete()

public boolean delete()
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.

Returns:
true if and only if the file or directory is successfully deleted; false otherwise
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkDelete(java.lang.String) sample code for java.lang.SecurityManager.checkDelete(java.lang.String) definition code for java.lang.SecurityManager.checkDelete(java.lang.String) method denies delete access to the file

deleteOnExit sample code for java.io.File.deleteOnExit() definition code for java.io.File.deleteOnExit()

public void deleteOnExit()
Requests that the file or directory denoted by this abstract pathname be deleted when the virtual machine terminates. 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 sample code for java.nio.channels.FileLock definition code for java.nio.channels.FileLock facility should be used instead.

Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkDelete(java.lang.String) sample code for java.lang.SecurityManager.checkDelete(java.lang.String) definition code for java.lang.SecurityManager.checkDelete(java.lang.String) method denies delete access to the file
Since:
1.2
See Also:
delete() sample code for java.io.File.delete() definition code for java.io.File.delete()

list sample code for java.io.File.list() definition code for java.io.File.list()

public String sample code for java.lang.String definition code for java.lang.String [] list()
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 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.

Returns:
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 null if this abstract pathname does not denote a directory, or if an I/O error occurs.
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the directory

list sample code for java.io.File.list(java.io.FilenameFilter) definition code for java.io.File.list(java.io.FilenameFilter)

public String sample code for java.lang.String definition code for java.lang.String [] list(FilenameFilter sample code for java.io.FilenameFilter definition code for java.io.FilenameFilter  filter)
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() sample code for java.io.File.list() definition code for java.io.File.list() method, except that the strings in the returned array must satisfy the filter. If the given filter is null then all names are accepted. Otherwise, a name satisfies the filter if and only if the value true results when the FilenameFilter.accept(java.io.File, java.lang.String) sample code for java.io.FilenameFilter.accept(java.io.File, java.lang.String) definition code for java.io.FilenameFilter.accept(java.io.File, java.lang.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.

Parameters:
filter - A filename filter
Returns:
An array of strings naming the files and directories in the directory denoted by this abstract pathname that were accepted by the given filter. The array will be empty if the directory is empty or if no names were accepted by the filter. Returns null if this abstract pathname does not denote a directory, or if an I/O error occurs.
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the directory

listFiles sample code for java.io.File.listFiles() definition code for java.io.File.listFiles()

public File sample code for java.io.File definition code for java.io.File [] listFiles()
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 null. Otherwise an array of 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) sample code for java.io.File.File(java.io.File, java.lang.String) definition code for java.io.File.File(java.io.File, java.lang.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.

Returns:
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 null if this abstract pathname does not denote a directory, or if an I/O error occurs.
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the directory
Since:
1.2

listFiles sample code for java.io.File.listFiles(java.io.FilenameFilter) definition code for java.io.File.listFiles(java.io.FilenameFilter)

public File sample code for java.io.File definition code for java.io.File [] listFiles(FilenameFilter sample code for java.io.FilenameFilter definition code for java.io.FilenameFilter  filter)
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() sample code for java.io.File.listFiles() definition code for java.io.File.listFiles() method, except that the pathnames in the returned array must satisfy the filter. If the given filter is null then all pathnames are accepted. Otherwise, a pathname satisfies the filter if and only if the value true results when the FilenameFilter.accept(java.io.File, java.lang.String) sample code for java.io.FilenameFilter.accept(java.io.File, java.lang.String) definition code for java.io.FilenameFilter.accept(java.io.File, java.lang.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.

Parameters:
filter - A filename filter
Returns:
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 null if this abstract pathname does not denote a directory, or if an I/O error occurs.
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the directory
Since:
1.2

listFiles sample code for java.io.File.listFiles(java.io.FileFilter) definition code for java.io.File.listFiles(java.io.FileFilter)

public File sample code for java.io.File definition code for java.io.File [] listFiles(FileFilter sample code for java.io.FileFilter definition code for java.io.FileFilter  filter)
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() sample code for java.io.File.listFiles() definition code for java.io.File.listFiles() method, except that the pathnames in the returned array must satisfy the filter. If the given filter is null then all pathnames are accepted. Otherwise, a pathname satisfies the filter if and only if the value true results when the FileFilter.accept(java.io.File) sample code for java.io.FileFilter.accept(java.io.File) definition code for java.io.FileFilter.accept(java.io.File) method of the filter is invoked on the pathname.

Parameters:
filter - A file filter
Returns:
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 null if this abstract pathname does not denote a directory, or if an I/O error occurs.
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to the directory
Since:
1.2

mkdir sample code for java.io.File.mkdir() definition code for java.io.File.mkdir()

public boolean mkdir()
Creates the directory named by this abstract pathname.

Returns:
true if and only if the directory was created; false otherwise
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkWrite(java.lang.String) sample code for java.lang.SecurityManager.checkWrite(java.lang.String) definition code for java.lang.SecurityManager.checkWrite(java.lang.String) method does not permit the named directory to be created

mkdirs sample code for java.io.File.mkdirs() definition code for java.io.File.mkdirs()

public boolean mkdirs()
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.

Returns:
true if and only if the directory was created, along with all necessary parent directories; false otherwise
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkRead(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for 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 SecurityManager.checkWrite(java.lang.String) sample code for java.lang.SecurityManager.checkWrite(java.lang.String) definition code for java.lang.SecurityManager.checkWrite(java.lang.String) method does not permit the named directory and all necessary parent directories to be created

renameTo sample code for java.io.File.renameTo(java.io.File) definition code for java.io.File.renameTo(java.io.File)

public boolean renameTo(File sample code for java.io.File definition code for java.io.File  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.

Parameters:
dest - The new abstract pathname for the named file
Returns:
true if and only if the renaming succeeded; false otherwise
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkWrite(java.lang.String) sample code for java.lang.SecurityManager.checkWrite(java.lang.String) definition code for java.lang.SecurityManager.checkWrite(java.lang.String) method denies write access to either the old or new pathnames
NullPointerException sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - If parameter dest is null

setLastModified sample code for java.io.File.setLastModified(long) definition code for java.io.File.setLastModified(long)

public boolean setLastModified(long 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() sample code for java.io.File.lastModified() definition code for java.io.File.lastModified() method will return the (possibly truncated) time argument that was passed to this method.

Parameters:
time - The new last-modified time, measured in milliseconds since the epoch (00:00:00 GMT, January 1, 1970)
Returns:
true if and only if the operation succeeded; false otherwise
Throws:
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - If the argument is negative
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkWrite(java.lang.String) sample code for java.lang.SecurityManager.checkWrite(java.lang.String) definition code for java.lang.SecurityManager.checkWrite(java.lang.String) method denies write access to the named file
Since:
1.2

setReadOnly sample code for java.io.File.setReadOnly() definition code for java.io.File.setReadOnly()

public boolean setReadOnly()
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.

Returns:
true if and only if the operation succeeded; false otherwise
Throws:
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkWrite(java.lang.String) sample code for java.lang.SecurityManager.checkWrite(java.lang.String) definition code for java.lang.SecurityManager.checkWrite(java.lang.String) method denies write access to the named file
Since:
1.2

listRoots sample code for java.io.File.listRoots() definition code for java.io.File.listRoots()

public static File sample code for java.io.File definition code for java.io.File [] listRoots()
List the available filesystem roots.

A particular Java platform may support zero or more hierarchically-organized file systems. Each file system has a 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 "/". 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 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, File objects denoting the root directories of the mapped network drives of a Windows platform will be returned by this method, while 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(java.lang.String) sample code for java.lang.SecurityManager.checkRead(java.lang.String) definition code for java.lang.SecurityManager.checkRead(java.lang.String) method denies read access to a particular root directory, then that directory will not appear in the result.

Returns:
An array of File objects denoting the available filesystem roots, or null if the set of roots could not be determined. The array will be empty if there are no filesystem roots.
Since:
1.2

createTempFile sample code for java.io.File.createTempFile(java.lang.String, java.lang.String, java.io.File) definition code for java.io.File.createTempFile(java.lang.String, java.lang.String, java.io.File)

public static File sample code for java.io.File definition code for java.io.File  createTempFile(String sample code for java.lang.String definition code for java.lang.String  prefix,
                                  String sample code for java.lang.String definition code for java.lang.String  suffix,
                                  File sample code for java.io.File definition code for java.io.File  directory)
                           throws IOException sample code for java.io.IOException definition code for java.io.IOException 

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() sample code for java.io.File.deleteOnExit() definition code for java.io.File.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.

Parameters:
prefix - The prefix string to be used in generating the file's name; must be at least three characters long
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
directory - The directory in which the file is to be created, or null if the default temporary-file directory is to be used
Returns:
An abstract pathname denoting a newly-created empty file
Throws:
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - If the prefix argument contains fewer than three characters
IOException sample code for java.io.IOException definition code for java.io.IOException - If a file could not be created
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkWrite(java.lang.String) sample code for java.lang.SecurityManager.checkWrite(java.lang.String) definition code for java.lang.SecurityManager.checkWrite(java.lang.String) method does not allow a file to be created
Since:
1.2

createTempFile sample code for java.io.File.createTempFile(java.lang.String, java.lang.String) definition code for java.io.File.createTempFile(java.lang.String, java.lang.String)

public static File sample code for java.io.File definition code for java.io.File  createTempFile(String sample code for java.lang.String definition code for java.lang.String  prefix,
                                  String sample code for java.lang.String definition code for java.lang.String  suffix)
                           throws IOException sample code for java.io.IOException definition code for java.io.IOException 
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 createTempFile(prefix, suffix, null) sample code for java.io.File.createTempFile(java.lang.String, java.lang.String, java.io.File) definition code for java.io.File.createTempFile(java.lang.String, java.lang.String, java.io.File) .

Parameters:
prefix - The prefix string to be used in generating the file's name; must be at least three characters long
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
Returns:
An abstract pathname denoting a newly-created empty file
Throws:
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - If the prefix argument contains fewer than three characters
IOException sample code for java.io.IOException definition code for java.io.IOException - If a file could not be created
SecurityException sample code for java.lang.SecurityException definition code for java.lang.SecurityException - If a security manager exists and its SecurityManager.checkWrite(java.lang.String) sample code for java.lang.SecurityManager.checkWrite(java.lang.String) definition code for java.lang.SecurityManager.checkWrite(java.lang.String) method does not allow a file to be created
Since:
1.2

compareTo sample code for java.io.File.compareTo(java.io.File) definition code for java.io.File.compareTo(java.io.File)

public int compareTo(File sample code for java.io.File definition code for java.io.File  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.

Specified by:
compareTo sample code for java.lang.Comparable.compareTo(T) definition code for java.lang.Comparable.compareTo(T) in interface Comparable sample code for java.lang.Comparable definition code for java.lang.Comparable <File sample code for java.io.File definition code for java.io.File >
Parameters:
pathname - The abstract pathname to be compared to this abstract pathname
Returns:
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

equals sample code for java.io.File.equals(java.lang.Object) definition code for java.io.File.equals(java.lang.Object)

public boolean equals(Object sample code for java.lang.Object definition code for java.lang.Object  obj)
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.

Overrides:
equals sample code for java.lang.Object.equals(java.lang.Object) definition code for java.lang.Object.equals(java.lang.Object) in class Object sample code for java.lang.Object definition code for java.lang.Object
Parameters:
obj - The object to be compared with this abstract pathname
Returns:
true if and only if the objects are the same; false otherwise
See Also:
Object.hashCode() sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() , Hashtable sample code for java.util.Hashtable definition code for java.util.Hashtable

hashCode sample code for java.io.File.hashCode() definition code for java.io.File.hashCode()

public int hashCode()
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.

Overrides:
hashCode sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() in class Object sample code for java.lang.Object definition code for java.lang.Object
Returns:
A hash code for this abstract pathname
See Also:
Object.equals(java.lang.Object) sample code for java.lang.Object.equals(java.lang.Object) definition code for java.lang.Object.equals(java.lang.Object) , Hashtable sample code for java.util.Hashtable definition code for java.util.Hashtable

toString sample code for java.io.File.toString() definition code for java.io.File.toString()

public String sample code for java.lang.String definition code for java.lang.String  toString()
Returns the pathname string of this abstract pathname. This is just the string returned by the getPath() sample code for java.io.File.getPath() definition code for java.io.File.getPath() method.

Overrides:
toString sample code for java.lang.Object.toString() definition code for java.lang.Object.toString() in class Object sample code for java.lang.Object definition code for java.lang.Object
Returns:
The string form of this abstract pathname