public final class WordDelimiterFilter extends TokenFilter
"Wi-Fi"
→ "Wi", "Fi"
"PowerShot"
→
"Power", "Shot"
"SD500"
→
"SD", "500"
"//hello---there, 'dude'"
→
"hello", "there", "dude"
"O'Neil's"
→ "O", "Neil"
"PowerShot"
→ 0:"Power", 1:"Shot"
(0 and 1 are the token positions)"PowerShot"
→
0:"Power", 1:"Shot" 1:"PowerShot"
"A's+B's&C's"
> 0:"A", 1:"B", 2:"C", 2:"ABC"
"Super-Duper-XL500-42-AutoCoder!"
→
0:"Super", 1:"Duper", 2:"XL", 2:"SuperDuperXL", 3:"500" 4:"42", 5:"Auto", 6:"Coder", 6:"AutoCoder"
WordDelimiterFilter
is to help match words with different
subword delimiters. For example, if the source text contained "wi-fi" one may
want "wifi" "WiFi" "wi-fi" "wi+fi" queries to all match. One way of doing so
is to specify combinations="1" in the analyzer used for indexing, and
combinations="0" (the default) in the analyzer used for querying. Given that
the current StandardTokenizer
immediately removes many intra-word
delimiters, it is recommended that this filter be used after a tokenizer that
does not do this (such as WhitespaceTokenizer
).Modifier and Type | Class and Description |
---|---|
private class |
WordDelimiterFilter.OffsetSorter |
(package private) class |
WordDelimiterFilter.WordDelimiterConcatenation
A WDF concatenated 'run'
|
AttributeSource.State
Modifier and Type | Field and Description |
---|---|
private int |
accumPosInc |
static int |
ALPHA |
static int |
ALPHANUM |
private AttributeSource.State[] |
buffered |
private int |
bufferedLen |
private int |
bufferedPos |
static int |
CATENATE_ALL
Causes all subword parts to be catenated:
|
static int |
CATENATE_NUMBERS
Causes maximum runs of word parts to be catenated:
|
static int |
CATENATE_WORDS
Causes maximum runs of word parts to be catenated:
|
private WordDelimiterFilter.WordDelimiterConcatenation |
concat |
private WordDelimiterFilter.WordDelimiterConcatenation |
concatAll |
static int |
DIGIT |
private boolean |
first |
private int |
flags |
static int |
GENERATE_NUMBER_PARTS
Causes number subwords to be generated:
|
static int |
GENERATE_WORD_PARTS
Causes parts of words to be generated:
|
private boolean |
hasIllegalOffsets |
private boolean |
hasOutputFollowingOriginal |
private boolean |
hasOutputToken |
private boolean |
hasSavedState |
private WordDelimiterIterator |
iterator |
private int |
lastConcatCount |
static int |
LOWER |
private OffsetAttribute |
offsetAttribute |
private int[] |
posInc |
private PositionIncrementAttribute |
posIncAttribute |
static int |
PRESERVE_ORIGINAL
Causes original words are preserved and added to the subword list (Defaults to false)
|
(package private) CharArraySet |
protWords
If not null is the set of tokens to protect from being delimited
|
private char[] |
savedBuffer |
private int |
savedEndOffset |
private int |
savedStartOffset |
private java.lang.String |
savedType |
(package private) WordDelimiterFilter.OffsetSorter |
sorter |
static int |
SPLIT_ON_CASE_CHANGE
If not set, causes case changes to be ignored (subwords will only be generated
given SUBWORD_DELIM tokens)
|
static int |
SPLIT_ON_NUMERICS
If not set, causes numeric changes to be ignored (subwords will only be generated
given SUBWORD_DELIM tokens).
|
private int[] |
startOff |
static int |
STEM_ENGLISH_POSSESSIVE
Causes trailing "'s" to be removed for each subword
|
static int |
SUBWORD_DELIM |
private CharTermAttribute |
termAttribute |
private TypeAttribute |
typeAttribute |
static int |
UPPER |
input
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
Constructor and Description |
---|
WordDelimiterFilter(TokenStream in,
byte[] charTypeTable,
int configurationFlags,
CharArraySet protWords)
Creates a new WordDelimiterFilter
|
WordDelimiterFilter(TokenStream in,
int configurationFlags,
CharArraySet protWords)
Creates a new WordDelimiterFilter using
WordDelimiterIterator.DEFAULT_WORD_DELIM_TABLE
as its charTypeTable |
Modifier and Type | Method and Description |
---|---|
private void |
buffer() |
private void |
concatenate(WordDelimiterFilter.WordDelimiterConcatenation concatenation)
Concatenates the saved buffer to the given WordDelimiterConcatenation
|
private boolean |
flushConcatenation(WordDelimiterFilter.WordDelimiterConcatenation concatenation)
Flushes the given WordDelimiterConcatenation by either writing its concat and then clearing, or just clearing.
|
private void |
generatePart(boolean isSingleWord)
Generates a word/number part, updating the appropriate attributes
|
private boolean |
has(int flag)
Determines whether the given flag is set
|
boolean |
incrementToken()
Consumers (i.e.,
IndexWriter ) use this method to advance the stream to
the next token. |
(package private) static boolean |
isAlpha(int type)
Checks if the given word type includes
ALPHA |
(package private) static boolean |
isDigit(int type)
Checks if the given word type includes
DIGIT |
(package private) static boolean |
isSubwordDelim(int type)
Checks if the given word type includes
SUBWORD_DELIM |
(package private) static boolean |
isUpper(int type)
Checks if the given word type includes
UPPER |
private int |
position(boolean inject)
Get the position increment gap for a subword or concatenation
|
void |
reset()
This method is called by a consumer before it begins consumption using
TokenStream.incrementToken() . |
private void |
saveState()
Saves the existing attribute states
|
private boolean |
shouldConcatenate(int wordType)
Determines whether to concatenate a word or number if the current word is the given type
|
private boolean |
shouldGenerateParts(int wordType)
Determines whether a word/number part should be generated for a word of the given type
|
close, end
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString
public static final int LOWER
public static final int UPPER
public static final int DIGIT
public static final int SUBWORD_DELIM
public static final int ALPHA
public static final int ALPHANUM
public static final int GENERATE_WORD_PARTS
"PowerShot" => "Power" "Shot"
public static final int GENERATE_NUMBER_PARTS
"500-42" => "500" "42"
public static final int CATENATE_WORDS
"wi-fi" => "wifi"
public static final int CATENATE_NUMBERS
"wi-fi" => "wifi"
public static final int CATENATE_ALL
"wi-fi-4000" => "wifi4000"
public static final int PRESERVE_ORIGINAL
"500-42" => "500" "42" "500-42"
public static final int SPLIT_ON_CASE_CHANGE
public static final int SPLIT_ON_NUMERICS
public static final int STEM_ENGLISH_POSSESSIVE
"O'Neil's" => "O", "Neil"
final CharArraySet protWords
private final int flags
private final CharTermAttribute termAttribute
private final OffsetAttribute offsetAttribute
private final PositionIncrementAttribute posIncAttribute
private final TypeAttribute typeAttribute
private final WordDelimiterIterator iterator
private final WordDelimiterFilter.WordDelimiterConcatenation concat
private int lastConcatCount
private final WordDelimiterFilter.WordDelimiterConcatenation concatAll
private int accumPosInc
private char[] savedBuffer
private int savedStartOffset
private int savedEndOffset
private java.lang.String savedType
private boolean hasSavedState
private boolean hasIllegalOffsets
private boolean hasOutputToken
private boolean hasOutputFollowingOriginal
private AttributeSource.State[] buffered
private int[] startOff
private int[] posInc
private int bufferedLen
private int bufferedPos
private boolean first
final WordDelimiterFilter.OffsetSorter sorter
public WordDelimiterFilter(TokenStream in, byte[] charTypeTable, int configurationFlags, CharArraySet protWords)
in
- TokenStream to be filteredcharTypeTable
- table containing character typesconfigurationFlags
- Flags configuring the filterprotWords
- If not null is the set of tokens to protect from being delimitedpublic WordDelimiterFilter(TokenStream in, int configurationFlags, CharArraySet protWords)
WordDelimiterIterator.DEFAULT_WORD_DELIM_TABLE
as its charTypeTablein
- TokenStream to be filteredconfigurationFlags
- Flags configuring the filterprotWords
- If not null is the set of tokens to protect from being delimitedpublic boolean incrementToken() throws java.io.IOException
TokenStream
IndexWriter
) use this method to advance the stream to
the next token. Implementing classes must implement this method and update
the appropriate AttributeImpl
s with the attributes of the next
token.
The producer must make no assumptions about the attributes after the method
has been returned: the caller may arbitrarily change it. If the producer
needs to preserve the state for subsequent calls, it can use
AttributeSource.captureState()
to create a copy of the current attribute state.
This method is called for every token of a document, so an efficient
implementation is crucial for good performance. To avoid calls to
AttributeSource.addAttribute(Class)
and AttributeSource.getAttribute(Class)
,
references to all AttributeImpl
s that this stream uses should be
retrieved during instantiation.
To ensure that filters and consumers know which attributes are available,
the attributes must be added during instantiation. Filters and consumers
are not required to check for availability of attributes in
TokenStream.incrementToken()
.
incrementToken
in class TokenStream
java.io.IOException
public void reset() throws java.io.IOException
TokenFilter
TokenStream.incrementToken()
.
Resets this stream to a clean state. Stateful implementations must implement this method so that they can be reused, just as if they had been created fresh.
If you override this method, always call super.reset()
, otherwise
some internal state will not be correctly reset (e.g., Tokenizer
will
throw IllegalStateException
on further usage).
NOTE:
The default implementation chains the call to the input TokenStream, so
be sure to call super.reset()
when overriding this method.
reset
in class TokenFilter
java.io.IOException
private void buffer()
private void saveState()
private boolean flushConcatenation(WordDelimiterFilter.WordDelimiterConcatenation concatenation)
concatenation
- WordDelimiterConcatenation that will be flushedtrue
if the concatenation was written before it was cleared, false
otherwiseprivate boolean shouldConcatenate(int wordType)
wordType
- Type of the current word used to determine if it should be concatenatedtrue
if concatenation should occur, false
otherwiseprivate boolean shouldGenerateParts(int wordType)
wordType
- Type of the word used to determine if a word/number part should be generatedtrue
if a word/number part should be generated, false
otherwiseprivate void concatenate(WordDelimiterFilter.WordDelimiterConcatenation concatenation)
concatenation
- WordDelimiterConcatenation to concatenate the buffer toprivate void generatePart(boolean isSingleWord)
isSingleWord
- true
if the generation is occurring from a single word, false
otherwiseprivate int position(boolean inject)
inject
- true if this token wants to be injectedstatic boolean isAlpha(int type)
ALPHA
type
- Word type to checktrue
if the type contains ALPHA, false
otherwisestatic boolean isDigit(int type)
DIGIT
type
- Word type to checktrue
if the type contains DIGIT, false
otherwisestatic boolean isSubwordDelim(int type)
SUBWORD_DELIM
type
- Word type to checktrue
if the type contains SUBWORD_DELIM, false
otherwisestatic boolean isUpper(int type)
UPPER
type
- Word type to checktrue
if the type contains UPPER, false
otherwiseprivate boolean has(int flag)
flag
- Flag to see if settrue
if flag is set