Package org.elasticsearch.index.mapper

Class SourceValueFetcher

java.lang.Object

org.elasticsearch.index.mapper.SourceValueFetcher

All Implemented Interfaces:

ValueFetcher

public abstract class SourceValueFetcher
extends Object
implements ValueFetcher

An implementation of ValueFetcher that knows how to extract values from the document source. Most standard field mappers will use this class to implement value fetching.

Field types that handle arrays directly should instead use ArraySourceValueFetcher.

Constructor Summary

Constructors

Constructor	Description
SourceValueFetcher(String fieldName, SearchExecutionContext context)
SourceValueFetcher(String fieldName, SearchExecutionContext context, Object nullValue)
SourceValueFetcher(Set<String> sourcePaths, Object nullValue)

Method Summary

Modifier and Type	Method	Description
List<Object>	fetchValues(SourceLookup lookup)	Given access to a document's _source, return this field's values.
static SourceValueFetcher	identity(String fieldName, SearchExecutionContext context, String format)	Creates a SourceValueFetcher that passes through source values unmodified.
protected abstract Object	parseSourceValue(Object value)	Given a value that has been extracted from a document's source, parse it into a standard format.
static SourceValueFetcher	toString(String fieldName, SearchExecutionContext context, String format)	Creates a SourceValueFetcher that converts source values to strings.
static SourceValueFetcher	toString(Set<String> sourcePaths)	Creates a SourceValueFetcher that converts source values to Strings

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.elasticsearch.index.mapper.ValueFetcher

setNextReader

Constructor Details

SourceValueFetcher

public SourceValueFetcher(String fieldName,
 SearchExecutionContext context)

SourceValueFetcher

public SourceValueFetcher(String fieldName,
 SearchExecutionContext context,
 Object nullValue)

Parameters:

fieldName - The name of the field.

context - The query shard context

nullValue - An optional substitute value if the _source value is 'null'.

SourceValueFetcher

public SourceValueFetcher(Set<String> sourcePaths,
 Object nullValue)

Parameters:

sourcePaths - The paths to pull source values from

nullValue - An optional substitute value if the _source value is `null`

Method Details

fetchValues

public List<Object> fetchValues(SourceLookup lookup)

Description copied from interface: ValueFetcher

Given access to a document's _source, return this field's values. In addition to pulling out the values, they will be parsed into a standard form. For example numeric field mappers make sure to parse the source value into a number of the right type. Note that for array values, the order in which values are returned is undefined and should not be relied on.

Specified by:

fetchValues in interface ValueFetcher

Parameters:

lookup - a lookup structure over the document's source.

Returns:

a list a standardized field values.

parseSourceValue

protected abstract Object parseSourceValue(Object value)

Given a value that has been extracted from a document's source, parse it into a standard format. This parsing logic should closely mirror the value parsing in FieldMapper.parseCreateField(org.elasticsearch.index.mapper.ParseContext) or FieldMapper.parse(org.elasticsearch.index.mapper.ParseContext).

identity

public static SourceValueFetcher identity(String fieldName,
 SearchExecutionContext context,
 String format)

Creates a SourceValueFetcher that passes through source values unmodified.

toString

public static SourceValueFetcher toString(String fieldName,
 SearchExecutionContext context,
 String format)

Creates a SourceValueFetcher that converts source values to strings.

toString

public static SourceValueFetcher toString(Set<String> sourcePaths)

Creates a SourceValueFetcher that converts source values to Strings

Parameters:

sourcePaths - the paths to fetch values from in the source