org.apache.lucene.store
Class Directory

java.lang.Object
  |
  +--org.apache.lucene.store.Directory

Direct Known Subclasses:

FSDirectory, RAMDirectory

public abstract class Directory

extends Object

A Directory is a flat list of files. Files may be written once, when they are created. Once a file is created it may only be opened for read, or deleted. Random access is permitted when reading and writing.

Author:

Doug Cutting

Constructor Summary

Directory()

Method Summary

abstract void	close() Closes the store.
abstract OutputStream	createFile(String name) Creates a new, empty file in the directory with the given name.
abstract void	deleteFile(String name) Removes an existing file in the directory.
abstract boolean	fileExists(String name) Returns true iff a file with the given name exists.
abstract long	fileLength(String name) Returns the length of a file in the directory.
abstract long	fileModified(String name) Returns the time the named file was last modified.
abstract String[]	list() Returns an array of strings, one for each file in the directory.
abstract Lock	makeLock(String name) Construct a Lock.
abstract InputStream	openFile(String name) Returns a stream reading an existing file.
abstract void	renameFile(String from, String to) Renames an existing file in the directory.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Directory

public Directory()

Method Detail

list

public abstract String[] list()
                       throws IOException,
                              SecurityException

Returns an array of strings, one for each file in the directory.

fileExists

public abstract boolean fileExists(String name)
                            throws IOException,
                                   SecurityException

Returns true iff a file with the given name exists.

fileModified

public abstract long fileModified(String name)
                           throws IOException,
                                  SecurityException

Returns the time the named file was last modified.

deleteFile

public abstract void deleteFile(String name)
                         throws IOException,
                                SecurityException

Removes an existing file in the directory.

renameFile

public abstract void renameFile(String from,
                                String to)
                         throws IOException,
                                SecurityException

Renames an existing file in the directory. If a file already exists with the new name, then it is replaced. This replacement should be atomic.

fileLength

public abstract long fileLength(String name)
                         throws IOException,
                                SecurityException

Returns the length of a file in the directory.

createFile

public abstract OutputStream createFile(String name)
                                 throws IOException,
                                        SecurityException

Creates a new, empty file in the directory with the given name. Returns a stream writing this file.

openFile

public abstract InputStream openFile(String name)
                              throws IOException,
                                     SecurityException

Returns a stream reading an existing file.

makeLock

public abstract Lock makeLock(String name)

Construct a Lock.

Parameters:

name - the name of the lock file

close

public abstract void close()
                    throws IOException,
                           SecurityException

Closes the store.