Class java.io.File
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Class java.io.File

java.lang.Object
   |
   +----java.io.File

public class File
extends Object
This class represents a file name of the host file system. The file name can be relative or absolute. It must use the file name conventions of the host platform.

The intention is to provide an abstraction that deals with most of the system-dependent file name features such as the separator character, root, device name, etc. Not all features are currently fully implemented.

Note that whenever a file name or path is used it is assumed that the host's file name conventions are used.


Variable Index

 o pathSeparator
The system dependent path separator string.
 o pathSeparatorChar
The system dependent path separator character.
 o separator
The system dependent file separator String.
 o separatorChar
The system dependent file separator character.

Constructor Index

 o File(File, String)
Creates a File object (given a directory File object).
 o File(String)
Creates a File object.
 o File(String, String)
Creates a File object from the specified directory.

Method Index

 o canRead()
Returns a boolean indicating whether or not a readable file exists.
 o canWrite()
Returns a boolean indicating whether or not a writable file exists.
 o delete()
Deletes the specified file.
 o equals(Object)
Compares this object against the specified object.
 o exists()
Returns a boolean indicating whether or not a file exists.
 o getAbsolutePath()
Gets the absolute path of the file.
 o getName()
Gets the name of the file.
 o getParent()
Gets the name of the parent directory.
 o getPath()
Gets the path of the file.
 o hashCode()
Computes a hashcode for the file.
 o isAbsolute()
Returns a boolean indicating whether the file name is absolute.
 o isDirectory()
Returns a boolean indicating whether or not a directory file exists.
 o isFile()
Returns a boolean indicating whether or not a normal file exists.
 o lastModified()
Returns the last modification time.
 o length()
Returns the length of the file.
 o list()
Lists the files in a directory.
 o list(FilenameFilter)
Uses the specified filter to list files in a directory.
 o mkdir()
Creates a directory and returns a boolean indicating the success of the creation.
 o mkdirs()
Creates all directories in this path.
 o renameTo(File)
Renames a file and returns a boolean indicating whether or not this method was successful.
 o toString()
Returns a String object representing this file's path.

Variables

 o separator
  public final static String separator
The system dependent file separator String.
 o separatorChar
  public final static char separatorChar
The system dependent file separator character.
 o pathSeparator
  public final static String pathSeparator
The system dependent path separator string.
 o pathSeparatorChar
  public final static char pathSeparatorChar
The system dependent path separator character.

Constructors

 o File
  public File(String path)
Creates a File object.
Parameters:
path - the file path
Throws: NullPointerException
If the file path is equal to null.
 o File
  public File(String path,
              String name)
Creates a File object from the specified directory.
Parameters:
path - the directory path
name - the file name
 o File
  public File(File dir,
              String name)
Creates a File object (given a directory File object).
Parameters:
dir - the directory
name - the file name

Methods

 o getName
  public String getName()
Gets the name of the file. This method does not include the directory.
Returns:
the file name.
 o getPath
  public String getPath()
Gets the path of the file.
Returns:
the file path.
 o getAbsolutePath
  public String getAbsolutePath()
Gets the absolute path of the file.
Returns:
the absolute file path.
 o getParent
  public String getParent()
Gets the name of the parent directory.
Returns:
the parent directory, or null if one is not found.
 o exists
  public boolean exists()
Returns a boolean indicating whether or not a file exists.
 o canWrite
  public boolean canWrite()
Returns a boolean indicating whether or not a writable file exists.
 o canRead
  public boolean canRead()
Returns a boolean indicating whether or not a readable file exists.
 o isFile
  public boolean isFile()
Returns a boolean indicating whether or not a normal file exists.
 o isDirectory
  public boolean isDirectory()
Returns a boolean indicating whether or not a directory file exists.
 o isAbsolute
  public boolean isAbsolute()
Returns a boolean indicating whether the file name is absolute.
 o lastModified
  public long lastModified()
Returns the last modification time. The return value should only be used to compare modification dates. It is meaningless as an absolute time.
 o length
  public long length()
Returns the length of the file.
 o mkdir
  public boolean mkdir()
Creates a directory and returns a boolean indicating the success of the creation.
 o renameTo
  public boolean renameTo(File dest)
Renames a file and returns a boolean indicating whether or not this method was successful.
Parameters:
dest - the new file name
 o mkdirs
  public boolean mkdirs()
Creates all directories in this path. This method returns true if all directories in this path are created.
 o list
  public String[] list()
Lists the files in a directory. Works only on directories.
Returns:
an array of file names. This list will include all files in the directory except the equivalent of "." and ".." .
 o list
  public String[] list(FilenameFilter filter)
Uses the specified filter to list files in a directory.
Parameters:
filter - the filter used to select file names
Returns:
the filter selected files in this directory.
See Also:
FilenameFilter
 o delete
  public boolean delete()
Deletes the specified file. Returns true if the file could be deleted.
 o hashCode
  public int hashCode()
Computes a hashcode for the file.
Overrides:
hashCode in class Object
 o equals
  public boolean equals(Object obj)
Compares this object against the specified object.
Parameters:
obj - the object to compare with
Returns:
true if the objects are the same; false otherwise.
Overrides:
equals in class Object
 o toString
  public String toString()
Returns a String object representing this file's path.
Overrides:
toString in class Object

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