Field Detail

• taxonomyWriter

  protected TaxonomyWriter taxonomyWriter

  A TaxonomyWriter for adding categories and retrieving their ordinals.

• categoryAttribute

  protected CategoryAttribute categoryAttribute

  An attribute containing all data related to the category

• ordinalProperty

  protected OrdinalProperty ordinalProperty

  A category property containing the category ordinal

Constructor Detail

• CategoryParentsStream

  public CategoryParentsStream​(CategoryAttributesStream input,
                               TaxonomyWriter taxonomyWriter,
                               FacetIndexingParams indexingParams)

  Constructor.

  Parameters:

  input - The input stream to handle, must be derived from CategoryAttributesStream.

  taxonomyWriter - The taxonomy writer to use for adding categories and retrieving their ordinals.

  indexingParams - The indexing params used for filtering parents.

Method Detail

• incrementToken

  public final 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

• clearCategoryProperties

  protected void clearCategoryProperties()

  Clear the properties of the current CategoryAttribute attribute before setting the parent attributes.
  It is possible to retain properties of certain types the parent tokens, using addRetainableProperty(Class).

• addRetainableProperty

  public void addRetainableProperty​(Class<? extends CategoryProperty> toRetain)

  Add a CategoryProperty class which is retained when creating parent tokens.

  Parameters:

  toRetain - The property class to retain.