Module org.apache.lucene.analysis.common
Package org.apache.lucene.analysis.pattern

Class SimplePatternTokenizer

java.lang.Object
org.apache.lucene.util.AttributeSource
org.apache.lucene.analysis.TokenStream
org.apache.lucene.analysis.Tokenizer
org.apache.lucene.analysis.pattern.SimplePatternTokenizer
All Implemented Interfaces:
Closeable, AutoCloseable
public final class SimplePatternTokenizer extends Tokenizer
This tokenizer uses a Lucene RegExp or (expert usage) a pre-built determinized Automaton, to locate tokens. The regexp syntax is more limited than PatternTokenizer, but the tokenization is quite a bit faster. The provided regex should match valid token characters (not token separator characters, like String.split). The matching is greedy: the longest match at a given start point will be the next token. Empty string tokens are never produced.

  • Field Details

    • termAtt

      private final CharTermAttribute termAtt

    • offsetAtt

      private final OffsetAttribute offsetAtt

    • runDFA

      private final CharacterRunAutomaton runDFA

    • pendingChars

      private char[] pendingChars

    • pendingLimit

      private int pendingLimit

    • pendingUpto

      private int pendingUpto

    • offset

      private int offset

    • tokenUpto

      private int tokenUpto

    • buffer

      private final char[] buffer

    • bufferLimit

      private int bufferLimit

    • bufferNextRead

      private int bufferNextRead

  • Constructor Details

    • SimplePatternTokenizer

      public SimplePatternTokenizer(String regexp)
      See RegExp for the accepted syntax.

    • SimplePatternTokenizer

      public SimplePatternTokenizer(Automaton dfa)
      Runs a pre-built automaton.

    • SimplePatternTokenizer

      public SimplePatternTokenizer(AttributeFactory factory, String regexp, int determinizeWorkLimit)
      See RegExp for the accepted syntax.

    • SimplePatternTokenizer

      public SimplePatternTokenizer(AttributeFactory factory, Automaton dfa)
      Runs a pre-built automaton.

  • Method Details

    • incrementToken

      public boolean incrementToken() throws IOException
      Description copied from class: TokenStream
      Consumers (i.e., IndexWriter) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriate AttributeImpls with the attributes of the next token.

      The producer must make no assumptions about the attributes after the method has been returned: the caller may arbitrarily change it. If the producer needs to preserve the state for subsequent calls, it can use AttributeSource.captureState() to create a copy of the current attribute state.

      This method is called for every token of a document, so an efficient implementation is crucial for good performance. To avoid calls to AttributeSource.addAttribute(Class) and AttributeSource.getAttribute(Class), references to all AttributeImpls that this stream uses should be retrieved during instantiation.

      To ensure that filters and consumers know which attributes are available, the attributes must be added during instantiation. Filters and consumers are not required to check for availability of attributes in TokenStream.incrementToken().

      Specified by:
      incrementToken in class TokenStream
      Returns:
      false for end of stream; true otherwise
      Throws:
      IOException

    • end

      public void end() throws IOException
      Description copied from class: TokenStream
      This method is called by the consumer after the last token has been consumed, after TokenStream.incrementToken() returned false (using the new TokenStream API). Streams implementing the old API should upgrade to use this feature.

      This method can be used to perform any end-of-stream operations, such as setting the final offset of a stream. The final offset of a stream might differ from the offset of the last token eg in case one or more whitespaces followed after the last token, but a WhitespaceTokenizer was used.

      Additionally any skipped positions (such as those removed by a stopfilter) can be applied to the position increment, or any adjustment of other attributes where the end-of-stream value may be important.

      If you override this method, always call super.end().

      Overrides:
      end in class TokenStream
      Throws:
      IOException - If an I/O error occurs

    • reset

      public void reset() throws IOException
      Description copied from class: TokenStream
      This method is called by a consumer before it begins consumption using TokenStream.incrementToken().

      Resets this stream to a clean state. Stateful implementations must implement this method so that they can be reused, just as if they had been created fresh.

      If you override this method, always call super.reset(), otherwise some internal state will not be correctly reset (e.g., Tokenizer will throw IllegalStateException on further usage).

      Overrides:
      reset in class Tokenizer
      Throws:
      IOException

    • pushBack

      private void pushBack(int count)
      Pushes back the last count characters in current token's buffer.

    • appendToToken

      private void appendToToken(char ch)

    • nextCodeUnit

      private int nextCodeUnit() throws IOException
      Throws:
      IOException

    • nextCodePoint

      private int nextCodePoint() throws IOException
      Throws:
      IOException