Package net.didion.jwnl.dictionary.file_manager

Class FileManagerImpl

java.lang.Object

net.didion.jwnl.dictionary.file_manager.FileManagerImpl

All Implemented Interfaces:

java.rmi.Remote, FileManager, Createable

Direct Known Subclasses:

RemoteFileManager

public class FileManagerImpl
extends java.lang.Object
implements FileManager

An implementation of FileManager that reads files from the local file system. FileManagerImpl caches the file position before and after readLineAt in order to eliminate the redundant IO activity that a naive implementation of these methods would necessitate.

Field Summary

Fields

Modifier and Type	Field	Description
private DictionaryCatalogSet	_files	The catalog set.
private static java.util.Random	_rand	Random number generator used by getRandomLineOffset().
static java.lang.String	FILE_TYPE	File type install parameter.
static java.lang.String	PATH	Dictionary path install parameter.

Constructor Summary

Constructors

Constructor	Description
FileManagerImpl()	Uninitialized FileManagerImpl.
FileManagerImpl(java.lang.String searchDir, java.lang.Class dictionaryFileType)	Construct a file manager backed by a set of files contained in the default WN search directory.

Method Summary

Modifier and Type	Method	Description
private void	checkFileType(java.lang.Class c)	Checks the type to ensure it's valid.
void	close()	Shut down the file manager.
java.lang.Object	create(java.util.Map params)
DictionaryFile	getFile(POS pos, DictionaryFileType fileType)	Gets the file from a part of speech and file type (ie data.noun).
long	getFirstLinePointer(POS pos, DictionaryFileType fileType)	Return the first valid line pointer in the specified file.
long	getIndexedLinePointer(POS pos, DictionaryFileType fileType, java.lang.String target)	Get indexed line pointer is typically used to find a word within an index file matching a given part of speech.
long	getMatchingLinePointer(POS pos, DictionaryFileType fileType, long offset, java.lang.String substring)	Search for a line whose index word contains substring, starting at offset.
long	getNextLinePointer(POS pos, DictionaryFileType fileType, long offset)	Search for the line following the line that begins at offset.
long	getRandomLinePointer(POS pos, DictionaryFileType fileType)	Return a randomly-chosen line pointer (offset of the beginning of a line).
java.lang.String	readLineAt(POS pos, DictionaryFileType fileType, long offset)	Read the line that begins at file offset offset.
private java.lang.String	readLineWord(RandomAccessDictionaryFile file)	Reads the first word from a file (ie offset, index word)
private void	skipLine(RandomAccessDictionaryFile file)	Skips the next line in the file.

Methods inherited from class java.lang.Object

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

Field Detail

FILE_TYPE

public static final java.lang.String FILE_TYPE

File type install parameter. The value should be the name of the appropriate subclass of DictionaryFileType.

See Also:

Constant Field Values

PATH

public static final java.lang.String PATH

Dictionary path install parameter. The value should be the absolute path of the directory containing the dictionary files.

See Also:

Constant Field Values

_rand

private static final java.util.Random _rand

Random number generator used by getRandomLineOffset().

_files

private DictionaryCatalogSet _files

The catalog set.

Constructor Detail

FileManagerImpl

public FileManagerImpl()

Uninitialized FileManagerImpl.

FileManagerImpl

public FileManagerImpl(java.lang.String searchDir,
                       java.lang.Class dictionaryFileType)
                throws java.io.IOException

Construct a file manager backed by a set of files contained in the default WN search directory.

Throws:

java.io.IOException

Method Detail

create

public java.lang.Object create(java.util.Map params)
                        throws JWNLException

Specified by:

create in interface Createable

Throws:

JWNLException

checkFileType

private void checkFileType(java.lang.Class c)

Checks the type to ensure it's valid.

Parameters:

c -

close

public void close()

Shut down the file manager.

Specified by:

close in interface FileManager

getFile

public DictionaryFile getFile(POS pos,
                              DictionaryFileType fileType)

Gets the file from a part of speech and file type (ie data.noun).

Parameters:

pos - - the part of speech (NOUN, ADJ, VERB, ADV)

fileType - - the file type (data, index, exc)

Returns:

- dictionary file

skipLine

private void skipLine(RandomAccessDictionaryFile file)
               throws java.io.IOException

Skips the next line in the file.

Parameters:

file -

Throws:

java.io.IOException

readLineAt

public java.lang.String readLineAt(POS pos,
                                   DictionaryFileType fileType,
                                   long offset)
                            throws java.io.IOException

Read the line that begins at file offset offset.

Specified by:

readLineAt in interface FileManager

Throws:

java.io.IOException

readLineWord

private java.lang.String readLineWord(RandomAccessDictionaryFile file)
                               throws java.io.IOException

Reads the first word from a file (ie offset, index word)

Parameters:

file - - the file

Returns:

- string

Throws:

java.io.IOException

getNextLinePointer

public long getNextLinePointer(POS pos,
                               DictionaryFileType fileType,
                               long offset)
                        throws java.io.IOException

Search for the line following the line that begins at offset.

Specified by:

getNextLinePointer in interface FileManager

Returns:

The file offset of the start of the line, or -1 if offset is the last line in the file.

Throws:

java.io.IOException

getMatchingLinePointer

public long getMatchingLinePointer(POS pos,
                                   DictionaryFileType fileType,
                                   long offset,
                                   java.lang.String substring)
                            throws java.io.IOException

Search for a line whose index word contains substring, starting at offset.

Specified by:

getMatchingLinePointer in interface FileManager

Returns:

The file offset of the start of the matchng line, or -1 if no such line exists.

Throws:

java.io.IOException

getIndexedLinePointer

public long getIndexedLinePointer(POS pos,
                                  DictionaryFileType fileType,
                                  java.lang.String target)
                           throws java.io.IOException

Get indexed line pointer is typically used to find a word within an index file matching a given part of speech. It first accesses the appropriate file (based on pos and dictionary type), then iterates through the file. Does so by using an offset and string comparison algorithm.

Specified by:

getIndexedLinePointer in interface FileManager

Returns:

The file offset of the start of the matching line, or -1 if no such line exists.

Throws:

java.io.IOException

getRandomLinePointer

public long getRandomLinePointer(POS pos,
                                 DictionaryFileType fileType)
                          throws java.io.IOException

Return a randomly-chosen line pointer (offset of the beginning of a line).

Specified by:

getRandomLinePointer in interface FileManager

Returns:

Throws:

java.io.IOException

getFirstLinePointer

public long getFirstLinePointer(POS pos,
                                DictionaryFileType fileType)
                         throws java.io.IOException

Return the first valid line pointer in the specified file.

Specified by:

getFirstLinePointer in interface FileManager

Returns:

Throws:

java.io.IOException