org.apache.solr.schema

Class RandomSortField

java.lang.Object

org.apache.solr.schema.FieldProperties

org.apache.solr.schema.FieldType

org.apache.solr.schema.RandomSortField

public class RandomSortField
extends FieldType

Utility Field used for random sorting. It should not be passed a value.

This random sorting implementation uses the dynamic field name to set the random 'seed'. To get random sorting order, you need to use a random dynamic field name. For example, you will need to configure schema.xml:

 <types>
  ...
  <fieldType name="random" class="solr.RandomSortField" />
  ... 
 </types>
 <fields>
  ...
  <dynamicField name="random*" type="random" indexed="true" stored="false"/>
  ...
 </fields>
 

Examples of queries:

• http://localhost:8983/solr/select/?q=*:*&fl=name&sort=rand_1234%20desc
• http://localhost:8983/solr/select/?q=*:*&fl=name&sort=rand_2345%20desc
• http://localhost:8983/solr/select/?q=*:*&fl=name&sort=rand_ABDC%20desc
• http://localhost:8983/solr/select/?q=*:*&fl=name&sort=rand_21%20desc

Note that multiple calls to the same URL will return the same sorting order.

Since:

solr 1.3

Version:

$Id: RandomSortField.java 1136465 2011-06-16 14:50:22Z mikemccand $

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	RandomSortField.RandomValueSource

Nested classes/interfaces inherited from class org.apache.solr.schema.FieldType

FieldType.DefaultAnalyzer

Field Summary

Fields

Modifier and Type	Field and Description
private static org.apache.lucene.search.FieldComparatorSource	randomComparatorSource

Fields inherited from class org.apache.solr.schema.FieldType

analyzer, args, falseProperties, log, POLY_FIELD_SEPARATOR, properties, queryAnalyzer, trueProperties, typeName

Fields inherited from class org.apache.solr.schema.FieldProperties

BINARY, INDEXED, MULTIVALUED, OMIT_NORMS, OMIT_POSITIONS, OMIT_TF_POSITIONS, propertyMap, propertyNames, REQUIRED, SORT_MISSING_FIRST, SORT_MISSING_LAST, STORE_TERMOFFSETS, STORE_TERMPOSITIONS, STORE_TERMVECTORS, STORED, TOKENIZED

Constructor Summary

Constructors

Constructor and Description
RandomSortField()

Method Summary

Modifier and Type	Method and Description
private static int	getSeed(java.lang.String fieldName, org.apache.lucene.index.IndexReader r) Given a field name and an IndexReader, get a random hash seed.
org.apache.lucene.search.SortField	getSortField(SchemaField field, boolean reverse) Returns the SortField instance that should be used to sort fields of this type.
ValueSource	getValueSource(SchemaField field, QParser parser) called to get the default value source (normally, from the Lucene FieldCache.)
private static int	hash(int key)
void	write(TextResponseWriter writer, java.lang.String name, org.apache.lucene.document.Fieldable f) calls back to TextResponseWriter to write the field value
void	write(XMLWriter xmlWriter, java.lang.String name, org.apache.lucene.document.Fieldable f) Renders the specified field as XML

Methods inherited from class org.apache.solr.schema.FieldType

createField, createField, createFields, getAnalyzer, getArg, getFieldIndex, getFieldQuery, getFieldStore, getFieldTermVec, getIndexOptions, getQueryAnalyzer, getRangeQuery, getStringSort, getTypeName, getValueSource, hasProperty, indexedToReadable, init, isMultiValued, isPolyField, isTokenized, multiValuedFieldCache, readableToIndexed, restrictProps, setAnalyzer, setArgs, setQueryAnalyzer, setTypeName, storedToIndexed, storedToReadable, toExternal, toInternal, toObject, toString

Methods inherited from class org.apache.solr.schema.FieldProperties

getPropertyName, off, on, parseProperties, propertiesToString, propertyNameToInt

Methods inherited from class java.lang.Object

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

Field Detail

randomComparatorSource

private static org.apache.lucene.search.FieldComparatorSource randomComparatorSource

Constructor Detail

RandomSortField

public RandomSortField()

Method Detail

hash

private static int hash(int key)

getSeed

private static int getSeed(java.lang.String fieldName,
                           org.apache.lucene.index.IndexReader r)

Given a field name and an IndexReader, get a random hash seed. Using dynamic fields, you can force the random order to change

getSortField

public org.apache.lucene.search.SortField getSortField(SchemaField field,
                                                       boolean reverse)

Description copied from class: FieldType

Returns the SortField instance that should be used to sort fields of this type.

Specified by:

getSortField in class FieldType

See Also:

SchemaField.checkSortability()

getValueSource

public ValueSource getValueSource(SchemaField field,
                                  QParser parser)

Description copied from class: FieldType

called to get the default value source (normally, from the Lucene FieldCache.)

Overrides:

getValueSource in class FieldType

write

public void write(XMLWriter xmlWriter,
                  java.lang.String name,
                  org.apache.lucene.document.Fieldable f)
           throws java.io.IOException

Description copied from class: FieldType

Renders the specified field as XML

Specified by:

write in class FieldType

Throws:

java.io.IOException

write

public void write(TextResponseWriter writer,
                  java.lang.String name,
                  org.apache.lucene.document.Fieldable f)
           throws java.io.IOException

Description copied from class: FieldType

calls back to TextResponseWriter to write the field value

Specified by:

write in class FieldType

Throws:

java.io.IOException