Class TrimFilter

  • All Implemented Interfaces:, java.lang.AutoCloseable

    public final class TrimFilter
    extends TokenFilter
    Trims leading and trailing whitespace from Tokens in the stream.

    As of Lucene 4.4, this filter does not support updateOffsets=true anymore as it can lead to broken token streams.

    • Constructor Detail

      • TrimFilter

        public TrimFilter​(Version version,
                          TokenStream in,
                          boolean updateOffsets)
        Offset updates are not supported anymore as of Lucene 4.4.
        Create a new TrimFilter.
        version - the Lucene match version
        in - the stream to consume
        updateOffsets - whether to update offsets
    • Method Detail

      • incrementToken

        public boolean incrementToken()
        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
        false for end of stream; true otherwise