WordDelimiterGraphFilter (Lucene 8.9.0 API)乐学网一站式学习平台

java.lang.Object
- org.apache.lucene.util.AttributeSource
- - org.apache.lucene.analysis.TokenStream
  - - org.apache.lucene.analysis.TokenFilter
    - - org.apache.lucene.analysis.miscellaneous.WordDelimiterGraphFilter

All Implemented Interfaces:

Closeable, AutoCloseable
```
public final class WordDelimiterGraphFilter
extends TokenFilter
```
Splits words into subwords and performs optional transformations on subword groups, producing a correct token graph so that e.g. PhraseQuery can work correctly when this filter is used in the search-time analyzer. Unlike the deprecated WordDelimiterFilter, this token filter produces a correct token graph as output. However, it cannot consume an input token graph correctly. Processing is suppressed by KeywordAttribute.isKeyword()=true.
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.
The GENERATE... options affect how incoming tokens are broken into parts, and the various CATENATE_... parameters affect how those parts are combined.
- 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.
One use for WordDelimiterGraphFilter 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

Fields
Modifier and Type	Field and Description
`static int`	`CATENATE_ALL` Causes all subword parts to be catenated:
`static int`	`CATENATE_NUMBERS` Causes maximum runs of number parts to be catenated:
`static int`	`CATENATE_WORDS` Causes maximum runs of word parts to be catenated:
`static int`	`GENERATE_NUMBER_PARTS` Causes number subwords to be generated:
`static int`	`GENERATE_WORD_PARTS` Causes parts of words to be generated:
`static int`	`IGNORE_KEYWORDS` Suppresses processing terms with `KeywordAttribute.isKeyword()`=true.
`static int`	`PRESERVE_ORIGINAL` Causes original words are preserved and added to the subword list (Defaults to false)
`static int`	`SPLIT_ON_CASE_CHANGE` Causes lowercase -> uppercase transition to start a new subword.
`static int`	`SPLIT_ON_NUMERICS` If not set, causes numeric changes to be ignored (subwords will only be generated given SUBWORD_DELIM tokens).
`static int`	`STEM_ENGLISH_POSSESSIVE` Causes trailing "'s" to be removed for each subword

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

Constructors
Constructor and Description
`WordDelimiterGraphFilter(TokenStream in, boolean adjustInternalOffsets, byte[] charTypeTable, int configurationFlags, CharArraySet protWords)` Creates a new WordDelimiterGraphFilter
`WordDelimiterGraphFilter(TokenStream in, int configurationFlags, CharArraySet protWords)` Creates a new WordDelimiterGraphFilter using `WordDelimiterIterator.DEFAULT_WORD_DELIM_TABLE` as its charTypeTable

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static String`	`flagsToString(int flags)` Returns string representation of configuration flags
`boolean`	`incrementToken()`
`void`	`reset()`
`String`	`toString()`

Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end

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

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - GENERATE_WORD_PARTS
```
public static final int GENERATE_WORD_PARTS
```
    Causes parts of words to be generated:
    "PowerShot" => "Power" "Shot"
    
    See Also:
    
    Constant Field Values
  - GENERATE_NUMBER_PARTS
```
public static final int GENERATE_NUMBER_PARTS
```
    Causes number subwords to be generated:
    "500-42" => "500" "42"
    
    See Also:
    
    Constant Field Values
  - CATENATE_WORDS
```
public static final int CATENATE_WORDS
```
    Causes maximum runs of word parts to be catenated:
    "wi-fi" => "wifi"
    
    See Also:
    
    Constant Field Values
  - CATENATE_NUMBERS
```
public static final int CATENATE_NUMBERS
```
    Causes maximum runs of number parts to be catenated:
    "500-42" => "50042"
    
    See Also:
    
    Constant Field Values
  - CATENATE_ALL
```
public static final int CATENATE_ALL
```
    Causes all subword parts to be catenated:
    "wi-fi-4000" => "wifi4000"
    
    See Also:
    
    Constant Field Values
  - PRESERVE_ORIGINAL
```
public static final int PRESERVE_ORIGINAL
```
    Causes original words are preserved and added to the subword list (Defaults to false)
    "500-42" => "500" "42" "500-42"
    
    See Also:
    
    Constant Field Values
  - SPLIT_ON_CASE_CHANGE
```
public static final int SPLIT_ON_CASE_CHANGE
```
    Causes lowercase -> uppercase transition to start a new subword.
    
    See Also:
    
    Constant Field Values
  - SPLIT_ON_NUMERICS
```
public static final int SPLIT_ON_NUMERICS
```
    If not set, causes numeric changes to be ignored (subwords will only be generated given SUBWORD_DELIM tokens).
    
    See Also:
    
    Constant Field Values
  - STEM_ENGLISH_POSSESSIVE
```
public static final int STEM_ENGLISH_POSSESSIVE
```
    Causes trailing "'s" to be removed for each subword
    "O'Neil's" => "O", "Neil"
    
    See Also:
    
    Constant Field Values
  - IGNORE_KEYWORDS
```
public static final int IGNORE_KEYWORDS
```
    Suppresses processing terms with KeywordAttribute.isKeyword()=true.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - WordDelimiterGraphFilter
```
public WordDelimiterGraphFilter(TokenStream in,
                                boolean adjustInternalOffsets,
                                byte[] charTypeTable,
                                int configurationFlags,
                                CharArraySet protWords)
```
    Creates a new WordDelimiterGraphFilter
    
    Parameters:
    
    in - TokenStream to be filtered
    
    adjustInternalOffsets - if the offsets of partial terms should be adjusted
    
    charTypeTable - table containing character types
    
    configurationFlags - Flags configuring the filter
    
    protWords - If not null is the set of tokens to protect from being delimited
  - WordDelimiterGraphFilter
```
public WordDelimiterGraphFilter(TokenStream in,
                                int configurationFlags,
                                CharArraySet protWords)
```
    Creates a new WordDelimiterGraphFilter using WordDelimiterIterator.DEFAULT_WORD_DELIM_TABLE as its charTypeTable
    
    Parameters:
    
    in - TokenStream to be filtered
    
    configurationFlags - Flags configuring the filter
    
    protWords - If not null is the set of tokens to protect from being delimited
- Method Detail
  - incrementToken
```
public boolean incrementToken()
                       throws IOException
```
    Specified by:
    
    incrementToken in class TokenStream
    
    Throws:
    
    IOException
  - reset
```
public void reset()
           throws IOException
```
    Overrides:
    
    reset in class TokenFilter
    
    Throws:
    
    IOException
  - flagsToString
```
public static String flagsToString(int flags)
```
    Returns string representation of configuration flags
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class AttributeSource

Class WordDelimiterGraphFilter

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource

Field Summary

Fields inherited from class org.apache.lucene.analysis.TokenFilter

Fields inherited from class org.apache.lucene.analysis.TokenStream

Constructor Summary

Method Summary

Methods inherited from class org.apache.lucene.analysis.TokenFilter

Methods inherited from class org.apache.lucene.util.AttributeSource

Methods inherited from class java.lang.Object

Field Detail

GENERATE_WORD_PARTS

GENERATE_NUMBER_PARTS

CATENATE_WORDS

CATENATE_NUMBERS

CATENATE_ALL

PRESERVE_ORIGINAL

SPLIT_ON_CASE_CHANGE

SPLIT_ON_NUMERICS

STEM_ENGLISH_POSSESSIVE

IGNORE_KEYWORDS

Constructor Detail

WordDelimiterGraphFilter

WordDelimiterGraphFilter

Method Detail

incrementToken

reset

flagsToString

toString