Package org.apache.lucene.monitor

# Class RegexpQueryHandler

java.lang.Object
org.apache.lucene.monitor.RegexpQueryHandler

All Implemented Interfaces:
  `CustomQueryHandler`

public class RegexpQueryHandler extends Object implements CustomQueryHandler
A query handler implementation that matches Regexp queries by indexing regex terms by their longest static substring, and generates ngrams from Document tokens to match them.

This implementation will filter out more wildcard queries than TermFilteredPresearcher, at the expense of longer document build times. Which one is more performant will depend on the type and number of queries registered in the Monitor, and the size of documents to be monitored. Profiling is recommended.

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final int`
  `DEFAULT_MAX_TOKEN_SIZE`
  The default maximum length of an input token before ANYTOKENS are generated
  `static final String`
  `DEFAULT_NGRAM_SUFFIX`
  The default suffix with which to mark ngrams
  `static final String`
  `DEFAULT_WILDCARD_TOKEN`
  The default token to emit if a term is longer than MAX_TOKEN_SIZE

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `RegexpQueryHandler()`
  Creates a new RegexpQueryHandler using default settings
  `RegexpQueryHandler(int maxTokenSize)`
  Creates a new RegexpQueryHandler with a maximum token size
  `RegexpQueryHandler(String ngramSuffix, int maxTokenSize, String wildcardToken, Set<String> excludedFields)`
  Creates a new RegexpQueryHandler

- ## Method Summary

  Modifier and Type
  Method
  Description
  `QueryTree`
  `handleQuery(Query q, TermWeightor termWeightor)`
  Builds a `QueryTree` node from a query
  `TokenStream`
  `wrapTermStream(String field, TokenStream ts)`
  Adds additional processing to the `TokenStream` over a document's terms index

  ### Methods inherited from class java.lang.Object

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

- ## Field Details

  - ### DEFAULT_NGRAM_SUFFIX

    public static final String DEFAULT_NGRAM_SUFFIX
    The default suffix with which to mark ngrams
    See Also:
      - Constant Field Values

  - ### DEFAULT_MAX_TOKEN_SIZE

    public static final int DEFAULT_MAX_TOKEN_SIZE
    The default maximum length of an input token before ANYTOKENS are generated
    See Also:
      - Constant Field Values

  - ### DEFAULT_WILDCARD_TOKEN

    public static final String DEFAULT_WILDCARD_TOKEN
    The default token to emit if a term is longer than MAX_TOKEN_SIZE
    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### RegexpQueryHandler

    public RegexpQueryHandler(String ngramSuffix, int maxTokenSize, String wildcardToken, Set<String> excludedFields)
    Creates a new RegexpQueryHandler
    Parameters:
      `ngramSuffix` - the suffix with which to mark ngrams
      `maxTokenSize` - the maximum length of an input token before WILDCARD tokens are generated
      `wildcardToken` - the token to emit if a token is longer than maxTokenSize in length
      `excludedFields` - a Set of fields to ignore when generating ngrams

  - ### RegexpQueryHandler

    public RegexpQueryHandler()
    Creates a new RegexpQueryHandler using default settings

  - ### RegexpQueryHandler

    public RegexpQueryHandler(int maxTokenSize)
    Creates a new RegexpQueryHandler with a maximum token size
    Parameters:
      `maxTokenSize` - the maximum length of an input token before WILDCARD tokens are generated

- ## Method Details

  - ### wrapTermStream

    public TokenStream wrapTermStream(String field, TokenStream ts)
    Description copied from interface: `CustomQueryHandler`
    Adds additional processing to the `TokenStream` over a document's terms index
    Specified by:
      `wrapTermStream` in interface `CustomQueryHandler`

  - ### handleQuery

    public QueryTree handleQuery(Query q, TermWeightor termWeightor)
    Description copied from interface: `CustomQueryHandler`
    Builds a `QueryTree` node from a query
    Specified by:
      `handleQuery` in interface `CustomQueryHandler`