org.apache.lucene.facet.params

Class CategoryListParams

java.lang.Object

org.apache.lucene.facet.params.CategoryListParams

Direct Known Subclasses:

PerDimensionOrdinalPolicy

public class CategoryListParams
extends Object

Contains parameters for a category list *

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CategoryListParams.OrdinalPolicy Defines which category ordinals are encoded for every document.

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_FIELD The default field used to store the facets information.
static CategoryListParams.OrdinalPolicy	DEFAULT_ORDINAL_POLICY The default CategoryListParams.OrdinalPolicy that's used when encoding a document's category ordinals.
String	field

Constructor Summary

Constructors

Constructor and Description
CategoryListParams() Constructs a default category list parameters object, using DEFAULT_FIELD.
CategoryListParams(String field) Constructs a category list parameters object, using the given field.

Method Summary

Methods

Modifier and Type	Method and Description
CategoryListIterator	createCategoryListIterator(int partition) Create the CategoryListIterator for the specified partition.
IntEncoder	createEncoder() Allows to override how categories are encoded and decoded.
boolean	equals(Object o)
CategoryListParams.OrdinalPolicy	getOrdinalPolicy(String dimension) Returns the CategoryListParams.OrdinalPolicy to use for the given dimension.
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_FIELD

public static final String DEFAULT_FIELD

The default field used to store the facets information.

See Also:

Constant Field Values

DEFAULT_ORDINAL_POLICY

public static final CategoryListParams.OrdinalPolicy DEFAULT_ORDINAL_POLICY

The default CategoryListParams.OrdinalPolicy that's used when encoding a document's category ordinals.

field

public final String field

Constructor Detail

CategoryListParams

public CategoryListParams()

Constructs a default category list parameters object, using DEFAULT_FIELD.

CategoryListParams

public CategoryListParams(String field)

Constructs a category list parameters object, using the given field.

Method Detail

createEncoder

public IntEncoder createEncoder()

Allows to override how categories are encoded and decoded. A matching IntDecoder is provided by the IntEncoder.

Default implementation creates a new Sorting(Unique(DGap)) encoder. Uniqueness in this regard means when the same category appears twice in a document, only one appearance would be encoded. This has effect on facet counting results.

Some possible considerations when overriding may be:

• an application "knows" that all categories are unique. So no need to pass through the unique filter.
• Another application might wish to count multiple occurrences of the same category, or, use a faster encoding which will consume more space.

In any event when changing this value make sure you know what you are doing, and test the results - e.g. counts, if the application is about counting facets.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

createCategoryListIterator

public CategoryListIterator createCategoryListIterator(int partition)
                                                throws IOException

Create the CategoryListIterator for the specified partition.

Throws:

IOException

getOrdinalPolicy

public CategoryListParams.OrdinalPolicy getOrdinalPolicy(String dimension)

Returns the CategoryListParams.OrdinalPolicy to use for the given dimension. This CategoryListParams always returns DEFAULT_ORDINAL_POLICY for all dimensions.

toString

public String toString()

Overrides:

toString in class Object