Class CharTokenizer
- All Implemented Interfaces:
Closeable
,AutoCloseable
- Direct Known Subclasses:
LetterTokenizer
,UnicodeWhitespaceTokenizer
,WhitespaceTokenizer
The base class also provides factories to create instances of CharTokenizer
using Java
8 lambdas or method references. It is possible to create an instance which behaves exactly like
LetterTokenizer
:
Tokenizer tok = CharTokenizer.fromTokenCharPredicate(Character::isLetter);
-
Nested Class Summary
Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.State
-
Field Summary
Fields inherited from class org.apache.lucene.analysis.TokenStream
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
-
Constructor Summary
ConstructorDescriptionCreates a newCharTokenizer
instanceCharTokenizer
(AttributeFactory factory) Creates a newCharTokenizer
instanceCharTokenizer
(AttributeFactory factory, int maxTokenLen) Creates a newCharTokenizer
instance -
Method Summary
Modifier and TypeMethodDescriptionfinal void
end()
static CharTokenizer
fromSeparatorCharPredicate
(IntPredicate separatorCharPredicate) Creates a new instance of CharTokenizer using a custom predicate, supplied as method reference or lambda expression.static CharTokenizer
fromSeparatorCharPredicate
(AttributeFactory factory, IntPredicate separatorCharPredicate) Creates a new instance of CharTokenizer with the supplied attribute factory using a custom predicate, supplied as method reference or lambda expression.static CharTokenizer
fromTokenCharPredicate
(IntPredicate tokenCharPredicate) Creates a new instance of CharTokenizer using a custom predicate, supplied as method reference or lambda expression.static CharTokenizer
fromTokenCharPredicate
(AttributeFactory factory, IntPredicate tokenCharPredicate) Creates a new instance of CharTokenizer with the supplied attribute factory using a custom predicate, supplied as method reference or lambda expression.final boolean
protected abstract boolean
isTokenChar
(int c) Returns true iff a codepoint should be included in a token.void
reset()
Methods inherited from class org.apache.lucene.analysis.Tokenizer
close, correctOffset, setReader, setReaderTestPoint
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
-
Field Details
-
DEFAULT_MAX_WORD_LEN
public static final int DEFAULT_MAX_WORD_LEN- See Also:
-
-
Constructor Details
-
CharTokenizer
public CharTokenizer()Creates a newCharTokenizer
instance -
CharTokenizer
Creates a newCharTokenizer
instance- Parameters:
factory
- the attribute factory to use for thisTokenizer
-
CharTokenizer
Creates a newCharTokenizer
instance- Parameters:
factory
- the attribute factory to use for thisTokenizer
maxTokenLen
- maximum token length the tokenizer will emit. Must be greater than 0 and less than MAX_TOKEN_LENGTH_LIMIT (1024*1024)- Throws:
IllegalArgumentException
- if maxTokenLen is invalid.
-
-
Method Details
-
fromTokenCharPredicate
Creates a new instance of CharTokenizer using a custom predicate, supplied as method reference or lambda expression. The predicate should returntrue
for all valid token characters.This factory is intended to be used with lambdas or method references. E.g., an elegant way to create an instance which behaves exactly as
LetterTokenizer
is:Tokenizer tok = CharTokenizer.fromTokenCharPredicate(Character::isLetter);
-
fromTokenCharPredicate
public static CharTokenizer fromTokenCharPredicate(AttributeFactory factory, IntPredicate tokenCharPredicate) Creates a new instance of CharTokenizer with the supplied attribute factory using a custom predicate, supplied as method reference or lambda expression. The predicate should returntrue
for all valid token characters.This factory is intended to be used with lambdas or method references. E.g., an elegant way to create an instance which behaves exactly as
LetterTokenizer
is:Tokenizer tok = CharTokenizer.fromTokenCharPredicate(factory, Character::isLetter);
-
fromSeparatorCharPredicate
Creates a new instance of CharTokenizer using a custom predicate, supplied as method reference or lambda expression. The predicate should returntrue
for all valid token separator characters. This method is provided for convenience to easily use predicates that are negated (they match the separator characters, not the token characters).This factory is intended to be used with lambdas or method references. E.g., an elegant way to create an instance which behaves exactly as
WhitespaceTokenizer
is:Tokenizer tok = CharTokenizer.fromSeparatorCharPredicate(Character::isWhitespace);
-
fromSeparatorCharPredicate
public static CharTokenizer fromSeparatorCharPredicate(AttributeFactory factory, IntPredicate separatorCharPredicate) Creates a new instance of CharTokenizer with the supplied attribute factory using a custom predicate, supplied as method reference or lambda expression. The predicate should returntrue
for all valid token separator characters.This factory is intended to be used with lambdas or method references. E.g., an elegant way to create an instance which behaves exactly as
WhitespaceTokenizer
is:Tokenizer tok = CharTokenizer.fromSeparatorCharPredicate(factory, Character::isWhitespace);
-
isTokenChar
protected abstract boolean isTokenChar(int c) Returns true iff a codepoint should be included in a token. This tokenizer generates as tokens adjacent sequences of codepoints which satisfy this predicate. Codepoints for which this is false are used to define token boundaries and are not included in tokens. -
incrementToken
- Specified by:
incrementToken
in classTokenStream
- Throws:
IOException
-
end
- Overrides:
end
in classTokenStream
- Throws:
IOException
-
reset
- Overrides:
reset
in classTokenizer
- Throws:
IOException
-