Package com.mongodb.client

Interface MapReduceIterable<TResult>

Type Parameters:

TResult - The type of the result.

All Superinterfaces:

Iterable<TResult>, MongoIterable<TResult>

public interface MapReduceIterable<TResult>
extends MongoIterable<TResult>

Iterable for map-reduce.

By default the MapReduceIterable returns the results inline. You can write map-reduce output to a collection by using the collectionName(String) method.

Since:

3.0

Method Summary

Modifier and Type	Method	Description
MapReduceIterable<TResult>	action(MapReduceAction action)	Specify the MapReduceAction to be used when writing to a collection.
MapReduceIterable<TResult>	batchSize(int batchSize)	Sets the number of documents to return per batch.
MapReduceIterable<TResult>	bypassDocumentValidation(Boolean bypassDocumentValidation)	Sets the bypass document level validation flag.
MapReduceIterable<TResult>	collation(Collation collation)	Sets the collation options
MapReduceIterable<TResult>	collectionName(String collectionName)	Sets the collectionName for the output of the MapReduce
MapReduceIterable<TResult>	databaseName(String databaseName)	Sets the name of the database to output into.
MapReduceIterable<TResult>	filter(Bson filter)	Sets the query filter to apply to the query.
MapReduceIterable<TResult>	finalizeFunction(String finalizeFunction)	Sets the JavaScript function that follows the reduce method and modifies the output.
MapReduceIterable<TResult>	jsMode(boolean jsMode)	Sets the flag that specifies whether to convert intermediate data into BSON format between the execution of the map and reduce functions.
MapReduceIterable<TResult>	limit(int limit)	Sets the limit to apply.
MapReduceIterable<TResult>	maxTime(long maxTime, TimeUnit timeUnit)	Sets the maximum execution time on the server for this operation.
MapReduceIterable<TResult>	nonAtomic(boolean nonAtomic)	Sets if the post-processing step will prevent MongoDB from locking the database.
MapReduceIterable<TResult>	scope(Bson scope)	Sets the global variables that are accessible in the map, reduce and finalize functions.
MapReduceIterable<TResult>	sharded(boolean sharded)	Sets if the output database is sharded
MapReduceIterable<TResult>	sort(Bson sort)	Sets the sort criteria to apply to the query.
void	toCollection()	Aggregates documents to a collection according to the specified map-reduce function with the given options, which must specify a non-inline result.
MapReduceIterable<TResult>	verbose(boolean verbose)	Sets whether to include the timing information in the result information.

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface com.mongodb.client.MongoIterable

first, forEach, into, iterator, map

Method Detail

toCollection

void toCollection()

Aggregates documents to a collection according to the specified map-reduce function with the given options, which must specify a non-inline result.

Throws:

IllegalStateException - if a collection name to write the results to has not been specified

Since:

3.4

See Also:

collectionName(String)

collectionName

MapReduceIterable<TResult> collectionName(String collectionName)

Sets the collectionName for the output of the MapReduce

The default action is replace the collection if it exists, to change this use action(com.mongodb.client.model.MapReduceAction).

Parameters:

collectionName - the name of the collection that you want the map-reduce operation to write its output.

Returns:

this

finalizeFunction

MapReduceIterable<TResult> finalizeFunction(@Nullable
                                            String finalizeFunction)

Sets the JavaScript function that follows the reduce method and modifies the output.

Parameters:

finalizeFunction - the JavaScript function that follows the reduce method and modifies the output.

Returns:

this

MongoDB documentation

Requirements for the finalize Function

scope

MapReduceIterable<TResult> scope(@Nullable
                                 Bson scope)

Sets the global variables that are accessible in the map, reduce and finalize functions.

Parameters:

scope - the global variables that are accessible in the map, reduce and finalize functions.

Returns:

this

MongoDB documentation

mapReduce

sort

MapReduceIterable<TResult> sort(@Nullable
                                Bson sort)

Sets the sort criteria to apply to the query.

Parameters:

sort - the sort criteria, which may be null.

Returns:

this

MongoDB documentation

Sort

filter

MapReduceIterable<TResult> filter(@Nullable
                                  Bson filter)

Sets the query filter to apply to the query.

Parameters:

filter - the filter to apply to the query.

Returns:

this

MongoDB documentation

Filter

limit

MapReduceIterable<TResult> limit(int limit)

Sets the limit to apply.

Parameters:

limit - the limit, which may be null

Returns:

this

MongoDB documentation

Limit

jsMode

MapReduceIterable<TResult> jsMode(boolean jsMode)

Sets the flag that specifies whether to convert intermediate data into BSON format between the execution of the map and reduce functions. Defaults to false.

Parameters:

jsMode - the flag that specifies whether to convert intermediate data into BSON format between the execution of the map and reduce functions

Returns:

jsMode

MongoDB documentation

mapReduce

verbose

MapReduceIterable<TResult> verbose(boolean verbose)

Sets whether to include the timing information in the result information.

Parameters:

verbose - whether to include the timing information in the result information.

Returns:

this

maxTime

MapReduceIterable<TResult> maxTime(long maxTime,
                                   TimeUnit timeUnit)

Sets the maximum execution time on the server for this operation.

Parameters:

maxTime - the max time

timeUnit - the time unit, which may not be null

Returns:

this

MongoDB documentation

Max Time

action

MapReduceIterable<TResult> action(MapReduceAction action)

Specify the MapReduceAction to be used when writing to a collection.

Parameters:

action - an MapReduceAction to perform on the collection

Returns:

this

databaseName

MapReduceIterable<TResult> databaseName(@Nullable
                                        String databaseName)

Sets the name of the database to output into.

Parameters:

databaseName - the name of the database to output into.

Returns:

this

MongoDB documentation

output with an action

sharded

MapReduceIterable<TResult> sharded(boolean sharded)

Sets if the output database is sharded

Parameters:

sharded - if the output database is sharded

Returns:

this

MongoDB documentation

output with an action

nonAtomic

MapReduceIterable<TResult> nonAtomic(boolean nonAtomic)

Sets if the post-processing step will prevent MongoDB from locking the database. Valid only with the MapReduceAction.MERGE or MapReduceAction.REDUCE actions.

Parameters:

nonAtomic - if the post-processing step will prevent MongoDB from locking the database.

Returns:

this

MongoDB documentation

output with an action

batchSize

MapReduceIterable<TResult> batchSize(int batchSize)

Sets the number of documents to return per batch.

Specified by:

batchSize in interface MongoIterable<TResult>

Parameters:

batchSize - the batch size

Returns:

this

MongoDB documentation

Batch Size

bypassDocumentValidation

MapReduceIterable<TResult> bypassDocumentValidation(@Nullable
                                                    Boolean bypassDocumentValidation)

Sets the bypass document level validation flag.

Note: This only applies when an $out stage is specified

.

Parameters:

bypassDocumentValidation - If true, allows the write to opt-out of document level validation.

Returns:

this

Since:

3.2

MongoDB documentation

mapReduce

Since server release

3.2

collation

MapReduceIterable<TResult> collation(@Nullable
                                     Collation collation)

Sets the collation options

A null value represents the server default.

Parameters:

collation - the collation options to use

Returns:

this

Since:

3.4

Since server release

3.4