org.apache.solr.request

Class IntervalFacets

java.lang.Object

org.apache.solr.request.IntervalFacets

All Implemented Interfaces:

Iterable<IntervalFacets.FacetInterval>

public class IntervalFacets
extends Object
implements Iterable<IntervalFacets.FacetInterval>

Computes interval facets for docvalues field (single or multivalued).

Given a set of intervals for a field and a DocSet, it calculates the number of documents that match each of the intervals provided. The final count for each interval should be exactly the same as the number of results of a range query using the DocSet and the range as filters. This means that the count of facet.query=field:[A TO B] should be the same as the count of f.field.facet.interval.set=[A,B], however, this method will usually be faster in cases where there are a larger number of intervals per field.

To use this class, create an instance using IntervalFacets(SchemaField, SolrIndexSearcher, DocSet, String[], SolrParams) and then iterate the IntervalFacets.FacetInterval using iterator()

Intervals Format
Intervals must begin with either '(' or '[', be followed by the start value, then a comma ',', the end value, and finally ')' or ']'. For example:

• (1,10) -> will include values greater than 1 and lower than 10
• [1,10) -> will include values greater or equal to 1 and lower than 10
• [1,10] -> will include values greater or equal to 1 and lower or equal to 10

The initial and end values can't be empty, if the interval needs to be unbounded, the special character '*' can be used for both, start and end limit. When using '*', '(' and '[', and ')' and ']' will be treated equal. [*,*] will include all documents with a value in the field

The interval limits may be strings, there is no need to add quotes, all the text until the comma will be treated as the start limit, and the text after that will be the end limit, for example: [Buenos Aires,New York]. Keep in mind that a string-like comparison will be done to match documents in string intervals (case-sensitive). The comparator can't be changed. Commas, brackets and square brackets can be escaped by using '\' in front of them. Whitespaces before and after the values will be omitted. Start limit can't be grater than the end limit. Equal limits are allowed.

As with facet.query, the key used to display the result can be set by using local params syntax, for example:

{!key='First Half'}[0,5)

To use this class:

 IntervalFacets intervalFacets = new IntervalFacets(schemaField, searcher, docs, intervalStrs, params);
 for (FacetInterval interval : intervalFacets) {
     results.add(interval.getKey(), interval.getCount());
 }
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	IntervalFacets.FacetInterval Helper class to match and count of documents in specified intervals

Constructor Summary

Constructors

Constructor and Description
IntervalFacets(SchemaField schemaField, SolrIndexSearcher searcher, DocSet docs, IntervalFacets.FacetInterval[] intervals) Constructor that accepts an already constructed array of IntervalFacets.FacetInterval objects.
IntervalFacets(SchemaField schemaField, SolrIndexSearcher searcher, DocSet docs, String[] intervals, SolrParams params) Constructor that accepts un-parsed intervals using "interval faceting" syntax.

Method Summary

Modifier and Type	Method and Description
Iterator<IntervalFacets.FacetInterval>	iterator() Iterate over all the intervals

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

IntervalFacets

public IntervalFacets(SchemaField schemaField,
                      SolrIndexSearcher searcher,
                      DocSet docs,
                      String[] intervals,
                      SolrParams params)
               throws SyntaxError,
                      IOException

Constructor that accepts un-parsed intervals using "interval faceting" syntax. See IntervalFacets for syntax. Intervals don't need to be in order.

Throws:

SyntaxError

IOException

IntervalFacets

public IntervalFacets(SchemaField schemaField,
                      SolrIndexSearcher searcher,
                      DocSet docs,
                      IntervalFacets.FacetInterval[] intervals)
               throws IOException

Constructor that accepts an already constructed array of IntervalFacets.FacetInterval objects. This array needs to be sorted by start value in weakly ascending order. null values are not allowed in the array.

Throws:

IOException

Method Detail

iterator

public Iterator<IntervalFacets.FacetInterval> iterator()

Iterate over all the intervals

Specified by:

iterator in interface Iterable<IntervalFacets.FacetInterval>