WordlistLoader (Lucene 10.5.0 core API)
Description: declaration: package: org.apache.lucene.analysis, class: WordlistLoader

Package org.apache.lucene.analysis

# Class WordlistLoader

java.lang.Object
org.apache.lucene.analysis.WordlistLoader

public class WordlistLoader extends Object
Loader for text files that represent a list of stopwords.

See Also:
  - `to obtain Reader instances`
NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `static List<String>`
  `getLines(InputStream stream, Charset charset)`
  Accesses a resource by name and returns the (non comment) lines containing data using the given character encoding.
  `static CharArraySet`
  `getSnowballWordSet(InputStream stream)`
  Reads stopwords from a stopword list in Snowball format.
  `static CharArraySet`
  `getSnowballWordSet(InputStream stream, Charset charset)`
  Reads stopwords from a stopword list in Snowball format.
  `static CharArraySet`
  `getSnowballWordSet(Reader reader)`
  Reads stopwords from a stopword list in Snowball format.
  `static CharArraySet`
  `getSnowballWordSet(Reader reader, CharArraySet result)`
  Reads stopwords from a stopword list in Snowball format.
  `static CharArrayMap<String>`
  `getStemDict(Reader reader, CharArrayMap<String> result)`
  Reads a stem dictionary.
  `static CharArraySet`
  `getWordSet(InputStream stream)`
  Reads lines from an InputStream with UTF-8 charset and adds every line as an entry to a CharArraySet (omitting leading and trailing whitespace).
  `static CharArraySet`
  `getWordSet(InputStream stream, String comment)`
  Reads lines from an InputStream with UTF-8 charset and adds every non-comment line as an entry to a CharArraySet (omitting leading and trailing whitespace).
  `static CharArraySet`
  `getWordSet(InputStream stream, Charset charset)`
  Reads lines from an InputStream with the given charset and adds every line as an entry to a CharArraySet (omitting leading and trailing whitespace).
  `static CharArraySet`
  `getWordSet(InputStream stream, Charset charset, String comment)`
  Reads lines from an InputStream with the given charset and adds every non-comment line as an entry to a CharArraySet (omitting leading and trailing whitespace).
  `static CharArraySet`
  `getWordSet(Reader reader)`
  Reads lines from a Reader and adds every line as an entry to a CharArraySet (omitting leading and trailing whitespace).
  `static CharArraySet`
  `getWordSet(Reader reader, String comment)`
  Reads lines from a Reader and adds every non-comment line as an entry to a CharArraySet (omitting leading and trailing whitespace).
  `static CharArraySet`
  `getWordSet(Reader reader, String comment, CharArraySet result)`
  Reads lines from a Reader and adds every non-blank non-comment line as an entry to a CharArraySet (omitting leading and trailing whitespace).
  `static CharArraySet`
  `getWordSet(Reader reader, CharArraySet result)`
  Reads lines from a Reader and adds every non-blank line as an entry to a CharArraySet (omitting leading and trailing whitespace).

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

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

- ## Method Details

  - ### getWordSet

    public static CharArraySet getWordSet(Reader reader, CharArraySet result) throws IOException
    Reads lines from a Reader and adds every non-blank line as an entry to a CharArraySet (omitting leading and trailing whitespace). Every line of the Reader should contain only one word. The words need to be in lowercase if you make use of an Analyzer which uses LowerCaseFilter (like StandardAnalyzer).
    Parameters:
      `reader` - Reader containing the wordlist
      `result` - the `CharArraySet` to fill with the readers words
    Returns:
      the given `CharArraySet` with the reader's words
    Throws:
      `IOException`

  - ### getWordSet

    public static CharArraySet getWordSet(Reader reader) throws IOException
    Reads lines from a Reader and adds every line as an entry to a CharArraySet (omitting leading and trailing whitespace). Every line of the Reader should contain only one word. The words need to be in lowercase if you make use of an Analyzer which uses LowerCaseFilter (like StandardAnalyzer).
    Parameters:
      `reader` - Reader containing the wordlist
    Returns:
      An unmodifiable `CharArraySet` with the reader's words
    Throws:
      `IOException`

  - ### getWordSet

    public static CharArraySet getWordSet(InputStream stream) throws IOException
    Reads lines from an InputStream with UTF-8 charset and adds every line as an entry to a CharArraySet (omitting leading and trailing whitespace). Every line of the Reader should contain only one word. The words need to be in lowercase if you make use of an Analyzer which uses LowerCaseFilter (like StandardAnalyzer).
    Parameters:
      `stream` - InputStream containing the wordlist
    Returns:
      An unmodifiable `CharArraySet` with the reader's words
    Throws:
      `IOException`

  - ### getWordSet

    public static CharArraySet getWordSet(InputStream stream, Charset charset) throws IOException
    Reads lines from an InputStream with the given charset and adds every line as an entry to a CharArraySet (omitting leading and trailing whitespace). Every line of the Reader should contain only one word. The words need to be in lowercase if you make use of an Analyzer which uses LowerCaseFilter (like StandardAnalyzer).
    Parameters:
      `stream` - InputStream containing the wordlist
      `charset` - Charset of the wordlist
    Returns:
      An unmodifiable `CharArraySet` with the reader's words
    Throws:
      `IOException`

  - ### getWordSet

    public static CharArraySet getWordSet(Reader reader, String comment, CharArraySet result) throws IOException
    Reads lines from a Reader and adds every non-blank non-comment line as an entry to a CharArraySet (omitting leading and trailing whitespace). Every line of the Reader should contain only one word. The words need to be in lowercase if you make use of an Analyzer which uses LowerCaseFilter (like StandardAnalyzer).
    Parameters:
      `reader` - Reader containing the wordlist
      `comment` - The string representing a comment.
      `result` - the `CharArraySet` to fill with the readers words
    Returns:
      the given `CharArraySet` with the reader's words
    Throws:
      `IOException`

  - ### getWordSet

    public static CharArraySet getWordSet(Reader reader, String comment) throws IOException
    Reads lines from a Reader and adds every non-comment line as an entry to a CharArraySet (omitting leading and trailing whitespace). Every line of the Reader should contain only one word. The words need to be in lowercase if you make use of an Analyzer which uses LowerCaseFilter (like StandardAnalyzer).
    Parameters:
      `reader` - Reader containing the wordlist
      `comment` - The string representing a comment.
    Returns:
      An unmodifiable CharArraySet with the reader's words
    Throws:
      `IOException`

  - ### getWordSet

    public static CharArraySet getWordSet(InputStream stream, String comment) throws IOException
    Reads lines from an InputStream with UTF-8 charset and adds every non-comment line as an entry to a CharArraySet (omitting leading and trailing whitespace). Every line of the Reader should contain only one word. The words need to be in lowercase if you make use of an Analyzer which uses LowerCaseFilter (like StandardAnalyzer).
    Parameters:
      `stream` - InputStream in UTF-8 encoding containing the wordlist
      `comment` - The string representing a comment.
    Returns:
      An unmodifiable CharArraySet with the reader's words
    Throws:
      `IOException`

  - ### getWordSet

    public static CharArraySet getWordSet(InputStream stream, Charset charset, String comment) throws IOException
    Reads lines from an InputStream with the given charset and adds every non-comment line as an entry to a CharArraySet (omitting leading and trailing whitespace). Every line of the Reader should contain only one word. The words need to be in lowercase if you make use of an Analyzer which uses LowerCaseFilter (like StandardAnalyzer).
    Parameters:
      `stream` - InputStream containing the wordlist
      `charset` - Charset of the wordlist
      `comment` - The string representing a comment.
    Returns:
      An unmodifiable CharArraySet with the reader's words
    Throws:
      `IOException`

  - ### getSnowballWordSet

    public static CharArraySet getSnowballWordSet(Reader reader, CharArraySet result) throws IOException
    Reads stopwords from a stopword list in Snowball format.

    The snowball format is the following:

    - Lines may contain multiple words separated by whitespace.
    - The comment character is the vertical line (|).
    - Lines may contain trailing comments.
    Parameters:
      `reader` - Reader containing a Snowball stopword list
      `result` - the `CharArraySet` to fill with the readers words
    Returns:
      the given `CharArraySet` with the reader's words
    Throws:
      `IOException`

  - ### getSnowballWordSet

    public static CharArraySet getSnowballWordSet(Reader reader) throws IOException
    Reads stopwords from a stopword list in Snowball format.

    The snowball format is the following:

    - Lines may contain multiple words separated by whitespace.
    - The comment character is the vertical line (|).
    - Lines may contain trailing comments.
    Parameters:
      `reader` - Reader containing a Snowball stopword list
    Returns:
      An unmodifiable `CharArraySet` with the reader's words
    Throws:
      `IOException`

  - ### getSnowballWordSet

    public static CharArraySet getSnowballWordSet(InputStream stream) throws IOException
    Reads stopwords from a stopword list in Snowball format.

    The snowball format is the following:

    - Lines may contain multiple words separated by whitespace.
    - The comment character is the vertical line (|).
    - Lines may contain trailing comments.
    Parameters:
      `stream` - InputStream in UTF-8 encoding containing a Snowball stopword list
    Returns:
      An unmodifiable `CharArraySet` with the reader's words
    Throws:
      `IOException`

  - ### getSnowballWordSet

    public static CharArraySet getSnowballWordSet(InputStream stream, Charset charset) throws IOException
    Reads stopwords from a stopword list in Snowball format.

    The snowball format is the following:

    - Lines may contain multiple words separated by whitespace.
    - The comment character is the vertical line (|).
    - Lines may contain trailing comments.
    Parameters:
      `stream` - InputStream containing a Snowball stopword list
      `charset` - Charset of the stopword list
    Returns:
      An unmodifiable `CharArraySet` with the reader's words
    Throws:
      `IOException`

  - ### getStemDict

    public static CharArrayMap<String> getStemDict(Reader reader, CharArrayMap<String> result) throws IOException
    Reads a stem dictionary. Each line contains:

        word\tstem

    (i.e. two tab separated words)
    Returns:
      stem dictionary that overrules the stemming algorithm
    Throws:
      `IOException` - If there is a low-level I/O error.

  - ### getLines

    public static List<String> getLines(InputStream stream, Charset charset) throws IOException
    Accesses a resource by name and returns the (non comment) lines containing data using the given character encoding.

    A comment line is any line that starts with the character "#"

    Returns:
      a list of non-blank non-comment lines with whitespace trimmed
    Throws:
      `IOException` - If there is a low-level I/O error.