MapReduceToCollectionOperation

java.lang.Object
- com.mongodb.operation.MapReduceToCollectionOperation

All Implemented Interfaces:

AsyncWriteOperation<MapReduceStatistics>, WriteOperation<MapReduceStatistics>
```
public class MapReduceToCollectionOperation
extends Object
implements AsyncWriteOperation<MapReduceStatistics>, WriteOperation<MapReduceStatistics>
```
Operation that runs a Map Reduce against a MongoDB instance. This operation does not support "inline" results, i.e. the results will be output into the collection represented by the MongoNamespace provided.
To run a map reduce operation and receive the results inline (i.e. as a response to running the command) use MapReduceToCollectionOperation.

Since:

3.0

MongoDB documentation

Map Reduce

Constructor Summary

Constructors
Constructor and Description
`MapReduceToCollectionOperation(MongoNamespace namespace, BsonJavaScript mapFunction, BsonJavaScript reduceFunction, String collectionName)` Construct a MapReduceOperation with all the criteria it needs to execute
`MapReduceToCollectionOperation(MongoNamespace namespace, BsonJavaScript mapFunction, BsonJavaScript reduceFunction, String collectionName, WriteConcern writeConcern)` Construct a MapReduceOperation with all the criteria it needs to execute

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`MapReduceToCollectionOperation`	`action(String action)` Sets the output action one of: "replace", "merge", "reduce"
`ReadOperation<BsonDocument>`	`asExplainableOperation(ExplainVerbosity explainVerbosity)` Gets an operation whose execution explains this operation.
`AsyncReadOperation<BsonDocument>`	`asExplainableOperationAsync(ExplainVerbosity explainVerbosity)` Gets an operation whose execution explains this operation.
`MapReduceToCollectionOperation`	`bypassDocumentValidation(Boolean bypassDocumentValidation)` Sets the bypass document level validation flag.
`MapReduceToCollectionOperation`	`collation(Collation collation)` Sets the collation options
`MapReduceToCollectionOperation`	`databaseName(String databaseName)` Sets the name of the database to output into.
`MapReduceStatistics`	`execute(WriteBinding binding)` Executing this will return a cursor with your results in.
`void`	`executeAsync(AsyncWriteBinding binding, SingleResultCallback<MapReduceStatistics> callback)` General execute which can return anything of type T
`MapReduceToCollectionOperation`	`filter(BsonDocument filter)` Sets the filter to apply to the query.
`MapReduceToCollectionOperation`	`finalizeFunction(BsonJavaScript finalizeFunction)` Sets the JavaScript function that follows the reduce method and modifies the output.
`String`	`getAction()` Gets the output action, one of: "replace", "merge", "reduce".
`Boolean`	`getBypassDocumentValidation()` Gets the bypass document level validation flag
`Collation`	`getCollation()` Returns the collation options
`String`	`getCollectionName()` Gets the name of the collection to output the results to.
`String`	`getDatabaseName()` Gets the name of the database to output into.
`BsonDocument`	`getFilter()` Gets the query filter.
`BsonJavaScript`	`getFinalizeFunction()` Gets the JavaScript function that follows the reduce method and modifies the output.
`int`	`getLimit()` Gets the limit to apply.
`BsonJavaScript`	`getMapFunction()` Gets the JavaScript function that associates or "maps" a value with a key and emits the key and value pair.
`long`	`getMaxTime(TimeUnit timeUnit)` Gets the maximum execution time on the server for this operation.
`MongoNamespace`	`getNamespace()` Gets the namespace.
`BsonJavaScript`	`getReduceFunction()` Gets the JavaScript function that "reduces" to a single object all the values associated with a particular key.
`BsonDocument`	`getScope()` Gets the global variables that are accessible in the map, reduce and finalize functions.
`BsonDocument`	`getSort()` Gets the sort criteria to apply to the query.
`WriteConcern`	`getWriteConcern()` Gets the write concern.
`boolean`	`isJsMode()` Gets the flag that specifies whether to convert intermediate data into BSON format between the execution of the map and reduce functions.
`boolean`	`isNonAtomic()` True if the post-processing step will prevent MongoDB from locking the database.
`boolean`	`isSharded()` True if the output database is sharded
`boolean`	`isVerbose()` Gets whether to include the timing information in the result information.
`MapReduceToCollectionOperation`	`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.
`MapReduceToCollectionOperation`	`limit(int limit)` Sets the limit to apply.
`MapReduceToCollectionOperation`	`maxTime(long maxTime, TimeUnit timeUnit)` Sets the maximum execution time on the server for this operation.
`MapReduceToCollectionOperation`	`nonAtomic(boolean nonAtomic)` Sets if the post-processing step will prevent MongoDB from locking the database.
`MapReduceToCollectionOperation`	`scope(BsonDocument scope)` Sets the global variables that are accessible in the map, reduce and finalize functions.
`MapReduceToCollectionOperation`	`sharded(boolean sharded)` Sets if the output database is sharded
`MapReduceToCollectionOperation`	`sort(BsonDocument sort)` Sets the sort criteria to apply to the query.
`MapReduceToCollectionOperation`	`verbose(boolean verbose)` Sets whether to include the timing information in the result information.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - MapReduceToCollectionOperation
```
public MapReduceToCollectionOperation(MongoNamespace namespace,
                                      BsonJavaScript mapFunction,
                                      BsonJavaScript reduceFunction,
                                      String collectionName)
```
    Construct a MapReduceOperation with all the criteria it needs to execute
    
    Parameters:
    
    namespace - the database and collection namespace for the operation.
    
    mapFunction - a JavaScript function that associates or "maps" a value with a key and emits the key and value pair.
    
    reduceFunction - a JavaScript function that "reduces" to a single object all the values associated with a particular key.
    
    collectionName - the name of the collection to output the results to.
    
    MongoDB documentation
    
    Map Reduce
  - MapReduceToCollectionOperation
```
public MapReduceToCollectionOperation(MongoNamespace namespace,
                                      BsonJavaScript mapFunction,
                                      BsonJavaScript reduceFunction,
                                      String collectionName,
                                      WriteConcern writeConcern)
```
    Construct a MapReduceOperation with all the criteria it needs to execute
    
    Parameters:
    
    namespace - the database and collection namespace for the operation.
    
    mapFunction - a JavaScript function that associates or "maps" a value with a key and emits the key and value pair.
    
    reduceFunction - a JavaScript function that "reduces" to a single object all the values associated with a particular key.
    
    collectionName - the name of the collection to output the results to.
    
    writeConcern - the write concern
    
    Since:
    
    3.4
    
    MongoDB documentation
    
    Map Reduce
- Method Detail
  - getNamespace
```
public MongoNamespace getNamespace()
```
    Gets the namespace.
    
    Returns:
    
    the namespace
    
    Since:
    
    3.4
  - getMapFunction
```
public BsonJavaScript getMapFunction()
```
    Gets the JavaScript function that associates or "maps" a value with a key and emits the key and value pair.
    
    Returns:
    
    the JavaScript function that associates or "maps" a value with a key and emits the key and value pair.
  - getReduceFunction
```
public BsonJavaScript getReduceFunction()
```
    Gets the JavaScript function that "reduces" to a single object all the values associated with a particular key.
    
    Returns:
    
    the JavaScript function that "reduces" to a single object all the values associated with a particular key.
  - getCollectionName
```
public String getCollectionName()
```
    Gets the name of the collection to output the results to.
    
    Returns:
    
    the name of the collection to output the results to.
  - getWriteConcern
```
public WriteConcern getWriteConcern()
```
    Gets the write concern.
    
    Returns:
    
    the write concern, which may be null
    
    Since:
    
    3.4
  - getFinalizeFunction
```
public BsonJavaScript getFinalizeFunction()
```
    Gets the JavaScript function that follows the reduce method and modifies the output. Default is null
    
    Returns:
    
    the JavaScript function that follows the reduce method and modifies the output.
    
    MongoDB documentation
    
    Requirements for the finalize Function
  - finalizeFunction
```
public MapReduceToCollectionOperation finalizeFunction(BsonJavaScript 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
  - getScope
```
public BsonDocument getScope()
```
    Gets the global variables that are accessible in the map, reduce and finalize functions.
    
    Returns:
    
    the global variables that are accessible in the map, reduce and finalize functions.
    
    MongoDB documentation
    
    Scope
  - scope
```
public MapReduceToCollectionOperation scope(BsonDocument 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
  - getFilter
```
public BsonDocument getFilter()
```
    Gets the query filter.
    
    Returns:
    
    the query filter
    
    MongoDB documentation
    
    Filter
  - filter
```
public MapReduceToCollectionOperation filter(BsonDocument filter)
```
    Sets the filter to apply to the query.
    
    Parameters:
    
    filter - the filter to apply to the query.
    
    Returns:
    
    this
    
    MongoDB documentation
    
    Filter
  - getSort
```
public BsonDocument getSort()
```
    Gets the sort criteria to apply to the query. The default is null, which means that the documents will be returned in an undefined order.
    
    Returns:
    
    a document describing the sort criteria
    
    MongoDB documentation
    
    Sort
  - sort
```
public MapReduceToCollectionOperation sort(BsonDocument sort)
```
    Sets the sort criteria to apply to the query.
    
    Parameters:
    
    sort - the sort criteria, which may be null.
    
    Returns:
    
    this
    
    MongoDB documentation
    
    Sort
  - getLimit
```
public int getLimit()
```
    Gets the limit to apply. The default is null.
    
    Returns:
    
    the limit
    
    MongoDB documentation
    
    Limit
  - limit
```
public MapReduceToCollectionOperation limit(int limit)
```
    Sets the limit to apply.
    
    Parameters:
    
    limit - the limit, which may be null
    
    Returns:
    
    this
    
    MongoDB documentation
    
    Limit
  - isJsMode
```
public boolean isJsMode()
```
    Gets the flag that specifies whether to convert intermediate data into BSON format between the execution of the map and reduce functions. Defaults to false.
    
    Returns:
    
    jsMode
    
    MongoDB documentation
    
    mapReduce
  - jsMode
```
public MapReduceToCollectionOperation 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
  - isVerbose
```
public boolean isVerbose()
```
    Gets whether to include the timing information in the result information. Defaults to true.
    
    Returns:
    
    whether to include the timing information in the result information
  - verbose
```
public MapReduceToCollectionOperation 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
  - getMaxTime
```
public long getMaxTime(TimeUnit timeUnit)
```
    Gets the maximum execution time on the server for this operation. The default is 0, which places no limit on the execution time.
    
    Parameters:
    
    timeUnit - the time unit to return the result in
    
    Returns:
    
    the maximum execution time in the given time unit
    
    MongoDB documentation
    
    Max Time
  - maxTime
```
public MapReduceToCollectionOperation 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
  - getAction
```
public String getAction()
```
    Gets the output action, one of: "replace", "merge", "reduce". Defaults to "replace".
    
    Returns:
    
    the output action
    
    MongoDB documentation
    
    output with an action
  - action
```
public MapReduceToCollectionOperation action(String action)
```
    Sets the output action one of: "replace", "merge", "reduce"
    
    Parameters:
    
    action - the output action
    
    Returns:
    
    this
    
    MongoDB documentation
    
    output with an action
  - getDatabaseName
```
public String getDatabaseName()
```
    Gets the name of the database to output into.
    
    Returns:
    
    the name of the database to output into.
  - databaseName
```
public MapReduceToCollectionOperation databaseName(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
  - isSharded
```
public boolean isSharded()
```
    True if the output database is sharded
    
    Returns:
    
    true if the output database is sharded
    
    MongoDB documentation
    
    output with an action
  - sharded
```
public MapReduceToCollectionOperation 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
  - isNonAtomic
```
public boolean isNonAtomic()
```
    True if the post-processing step will prevent MongoDB from locking the database.
    
    Returns:
    
    if true the post-processing step will prevent MongoDB from locking the database.
    
    MongoDB documentation
    
    output with an action
  - nonAtomic
```
public MapReduceToCollectionOperation nonAtomic(boolean nonAtomic)
```
    Sets if the post-processing step will prevent MongoDB from locking the database. Valid only with "merge" or "reduce" actions.
    
    Parameters:
    
    nonAtomic - if the post-processing step will prevent MongoDB from locking the database.
    
    Returns:
    
    this
    
    MongoDB documentation
    
    output with an action
  - getBypassDocumentValidation
```
public Boolean getBypassDocumentValidation()
```
    Gets the bypass document level validation flag
    
    Returns:
    
    the bypass document level validation flag
    
    Since:
    
    3.2
    
    Since server release
    
    3.2
  - bypassDocumentValidation
```
public MapReduceToCollectionOperation bypassDocumentValidation(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
    
    Since server release
    
    3.2
  - getCollation
```
public Collation getCollation()
```
    Returns the collation options
    
    Returns:
    
    the collation options
    
    Since:
    
    3.4
    
    Since server release
    
    3.4
  - collation
```
public MapReduceToCollectionOperation collation(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
  - execute
```
public MapReduceStatistics execute(WriteBinding binding)
```
    Executing this will return a cursor with your results in.
    
    Specified by:
    
    execute in interface WriteOperation<MapReduceStatistics>
    
    Parameters:
    
    binding - the binding
    
    Returns:
    
    a MongoCursor that can be iterated over to find all the results of the Map Reduce operation.
  - executeAsync
```
public void executeAsync(AsyncWriteBinding binding,
                         SingleResultCallback<MapReduceStatistics> callback)
```
    Description copied from interface: AsyncWriteOperation
    
    General execute which can return anything of type T
    
    Specified by:
    
    executeAsync in interface AsyncWriteOperation<MapReduceStatistics>
    
    Parameters:
    
    binding - the binding to execute in the context of
    
    callback - the callback to be called when the operation has been executed
  - asExplainableOperation
```
public ReadOperation<BsonDocument> asExplainableOperation(ExplainVerbosity explainVerbosity)
```
    Gets an operation whose execution explains this operation.
    
    Parameters:
    
    explainVerbosity - the explain verbosity
    
    Returns:
    
    a read operation that when executed will explain this operation
  - asExplainableOperationAsync
```
public AsyncReadOperation<BsonDocument> asExplainableOperationAsync(ExplainVerbosity explainVerbosity)
```
    Gets an operation whose execution explains this operation.
    
    Parameters:
    
    explainVerbosity - the explain verbosity
    
    Returns:
    
    a read operation that when executed will explain this operation

Class MapReduceToCollectionOperation

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

MapReduceToCollectionOperation

MapReduceToCollectionOperation

Method Detail

getNamespace

getMapFunction

getReduceFunction

getCollectionName

getWriteConcern

getFinalizeFunction

finalizeFunction

getScope

scope

getFilter

filter

getSort

sort

getLimit

limit

isJsMode

jsMode

isVerbose

verbose

getMaxTime

maxTime

getAction

action

getDatabaseName

databaseName

isSharded

sharded

isNonAtomic

nonAtomic

getBypassDocumentValidation

bypassDocumentValidation

getCollation

collation

execute

executeAsync

asExplainableOperation

asExplainableOperationAsync