Class WordDelimiterFilter
java.lang.Object
org.apache.lucene.util.AttributeSource
org.apache.lucene.analysis.TokenStream
org.apache.lucene.analysis.TokenFilter
org.apache.lucene.analysis.miscellaneous.WordDelimiterFilter
- All Implemented Interfaces:
Closeable
,AutoCloseable
,Unwrappable<TokenStream>
Deprecated.
Splits words into subwords and performs optional transformations on subword groups. Words are
split into subwords with the following rules:
- split on intra-word delimiters (by default, all non alpha-numeric characters):
"Wi-Fi"
→"Wi", "Fi"
- split on case transitions:
"PowerShot"
→"Power", "Shot"
- split on letter-number transitions:
"SD500"
→"SD", "500"
- leading and trailing intra-word delimiters on each subword are ignored:
"//hello---there, 'dude'"
→"hello", "there", "dude"
- trailing "'s" are removed for each subword:
"O'Neil's"
→"O", "Neil"
- Note: this step isn't performed in a separate filter because of possible subword combinations.
- If no CATENATE option is set, then no subword combinations are generated:
"PowerShot"
→0:"Power", 1:"Shot"
(0 and 1 are the token positions) - CATENATE_WORDS means that in addition to the subwords, maximum runs of non-numeric subwords
are catenated and produced at the same position of the last subword in the run:
"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"
- CATENATE_NUMBERS works like CATENATE_WORDS, but for adjacent digit sequences.
- CATENATE_ALL smushes together all the token parts without distinguishing numbers and words.
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 CATENATE options in the analyzer used for
indexing, and not 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
).-
Nested Class Summary
Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.State
-
Field Summary
Modifier and TypeFieldDescriptionstatic final int
Deprecated.static final int
Deprecated.static final int
Deprecated.Causes all subword parts to be catenated:static final int
Deprecated.Causes maximum runs of word parts to be catenated:static final int
Deprecated.Causes maximum runs of word parts to be catenated:static final int
Deprecated.static final int
Deprecated.Causes number subwords to be generated:static final int
Deprecated.Causes parts of words to be generated:static final int
Deprecated.Suppresses processing terms withKeywordAttribute.isKeyword()
=true.static final int
Deprecated.static final int
Deprecated.Causes original words are preserved and added to the subword list (Defaults to false)static final int
Deprecated.If not set, causes case changes to be ignored (subwords will only be generated given SUBWORD_DELIM tokens)static final int
Deprecated.If not set, causes numeric changes to be ignored (subwords will only be generated given SUBWORD_DELIM tokens).static final int
Deprecated.Causes trailing "'s" to be removed for each subwordstatic final int
Deprecated.static final int
Deprecated.Fields inherited from class org.apache.lucene.analysis.TokenFilter
input
Fields inherited from class org.apache.lucene.analysis.TokenStream
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
-
Constructor Summary
ConstructorDescriptionWordDelimiterFilter
(TokenStream in, byte[] charTypeTable, int configurationFlags, CharArraySet protWords) Deprecated.Creates a new WordDelimiterFilterWordDelimiterFilter
(TokenStream in, int configurationFlags, CharArraySet protWords) Deprecated.Creates a new WordDelimiterFilter usingWordDelimiterIterator.DEFAULT_WORD_DELIM_TABLE
as its charTypeTable -
Method Summary
Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end, unwrap
Methods inherited from class org.apache.lucene.util.AttributeSource
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString
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Field Details
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LOWER
public static final int LOWERDeprecated.- See Also:
-
UPPER
public static final int UPPERDeprecated.- See Also:
-
DIGIT
public static final int DIGITDeprecated.- See Also:
-
SUBWORD_DELIM
public static final int SUBWORD_DELIMDeprecated.- See Also:
-
ALPHA
public static final int ALPHADeprecated.- See Also:
-
ALPHANUM
public static final int ALPHANUMDeprecated.- See Also:
-
GENERATE_WORD_PARTS
public static final int GENERATE_WORD_PARTSDeprecated.Causes parts of words to be generated:"PowerShot" => "Power" "Shot"
- See Also:
-
GENERATE_NUMBER_PARTS
public static final int GENERATE_NUMBER_PARTSDeprecated.Causes number subwords to be generated:"500-42" => "500" "42"
- See Also:
-
CATENATE_WORDS
public static final int CATENATE_WORDSDeprecated.Causes maximum runs of word parts to be catenated:"wi-fi" => "wifi"
- See Also:
-
CATENATE_NUMBERS
public static final int CATENATE_NUMBERSDeprecated.Causes maximum runs of word parts to be catenated:"500-42" => "50042"
- See Also:
-
CATENATE_ALL
public static final int CATENATE_ALLDeprecated.Causes all subword parts to be catenated:"wi-fi-4000" => "wifi4000"
- See Also:
-
PRESERVE_ORIGINAL
public static final int PRESERVE_ORIGINALDeprecated.Causes original words are preserved and added to the subword list (Defaults to false)"500-42" => "500" "42" "500-42"
- See Also:
-
SPLIT_ON_CASE_CHANGE
public static final int SPLIT_ON_CASE_CHANGEDeprecated.If not set, causes case changes to be ignored (subwords will only be generated given SUBWORD_DELIM tokens)- See Also:
-
SPLIT_ON_NUMERICS
public static final int SPLIT_ON_NUMERICSDeprecated.If not set, causes numeric changes to be ignored (subwords will only be generated given SUBWORD_DELIM tokens).- See Also:
-
STEM_ENGLISH_POSSESSIVE
public static final int STEM_ENGLISH_POSSESSIVEDeprecated.Causes trailing "'s" to be removed for each subword"O'Neil's" => "O", "Neil"
- See Also:
-
IGNORE_KEYWORDS
public static final int IGNORE_KEYWORDSDeprecated.Suppresses processing terms withKeywordAttribute.isKeyword()
=true.- See Also:
-
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Constructor Details
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WordDelimiterFilter
public WordDelimiterFilter(TokenStream in, byte[] charTypeTable, int configurationFlags, CharArraySet protWords) Deprecated.Creates a new WordDelimiterFilter- Parameters:
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 delimited
-
WordDelimiterFilter
Deprecated.Creates a new WordDelimiterFilter usingWordDelimiterIterator.DEFAULT_WORD_DELIM_TABLE
as its charTypeTable- Parameters:
in
- TokenStream to be filteredconfigurationFlags
- Flags configuring the filterprotWords
- If not null is the set of tokens to protect from being delimited
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Method Details
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incrementToken
Deprecated.- Specified by:
incrementToken
in classTokenStream
- Throws:
IOException
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reset
Deprecated.- Overrides:
reset
in classTokenFilter
- Throws:
IOException
-
WordDelimiterGraphFilter
instead: it produces a correct token graph so that e.g.PhraseQuery
works correctly when it's used in the search time analyzer.