Documentation  › org.apache.lucene.store  › Directory
 
 


  Directory
  public abstract

  Inherits From:   Object
  Conforms To:   none
  Declared In:   org.apache.lucene.store


Class Description
 
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 both when reading and writing.

Java's i/o APIs not used directly, but rather all i/o is through this API. This permits things such as:

  • implementation of RAM-based indices;
  • implementation indices stored in a database, via JDBC;
  • implementation of an index as a single file;


Class Variables
 
None declared in this class.


Instance Variables
 
None declared in this class.


Constructors
 
Directory
public Directory( )

No description available for this constructor.


Class Methods
 
None declared in this class.


Instance Methods
 
close
public abstract void close( ) throws IOException

Closes the store.


createFile
public abstract OutputStream createFile( String name ) throws IOException

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


deleteFile
public abstract void deleteFile( String name ) throws IOException

Removes an existing file in the directory.


fileExists
public abstract boolean fileExists( String name ) throws IOException

Returns true iff a file with the given name exists.


fileLength
public abstract long fileLength( String name ) throws IOException

Returns the length of a file in the directory.


fileModified
public abstract long fileModified( String name ) throws IOException

Returns the time the named file was last modified.


list
public abstract String[] list( ) throws IOException

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


makeLock
public abstract Lock makeLock( String name )

Construct a Lock.


openFile
public abstract InputStream openFile( String name ) throws IOException

Returns a stream reading an existing file.


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

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.


touchFile
public abstract void touchFile( String name ) throws IOException

Set the modified time of an existing file to now.


Known Subclasses
 
FSDirectory, RAMDirectory



 
 
  dydoc
  3/9/05