MapReduce (mongodb-async-driver 2.0.1 API)

java.lang.Object
- com.allanbank.mongodb.builder.MapReduce

```
public class MapReduce
extends Object
```
Represents the state of a single MongoCollection.mapReduce(com.allanbank.mongodb.builder.MapReduce) command. Objects of this class are created using the nested MapReduce.Builder.

API Notice:

This class is part of the driver's API. Public and protected members will be deprecated for at least 1 non-bugfix release (version numbers are <major>.<minor>.<bugfix>) before being removed or modified.

Copyright ©:

2011-2013, Allanbank Consulting, Inc., All Rights Reserved

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`MapReduce.Builder` Helper for creating immutable `MapReduce` commands.
`static class`	`MapReduce.OutputType` Enumeration of the possible output types.

Field Summary

Fields
Modifier and Type	Field and Description
`static Version`	`MAX_TIMEOUT_VERSION` The first version of MongoDB to support the `mapreduce` command with the ability to limit the execution time on the server.

Constructor Summary

Constructors
Modifier Constructor and Description

protected MapReduce(MapReduce.Builder builder)
Create a new MapReduce.

Constructors
Modifier	Constructor and Description
`protected`	`MapReduce(MapReduce.Builder builder)` Create a new MapReduce.

Method Summary

Methods
Modifier and Type	Method and Description
`static MapReduce.Builder`	`builder()` Creates a new builder for a `MapReduce`.
`String`	`getFinalizeFunction()` Returns the finalize function to apply to the final results of the reduce function.
`int`	`getLimit()` Returns the limit for the number of objects to be used as input to the map/reduce.
`String`	`getMapFunction()` Returns the map functions to apply to each selected document.
`long`	`getMaximumTimeMilliseconds()` Returns the maximum amount of time to allow the command to run on the Server before it is aborted.
`String`	`getOutputDatabase()` Returns the name of the output database if the output type is One of `MapReduce.OutputType.REPLACE`, `MapReduce.OutputType.MERGE`, or `MapReduce.OutputType.REDUCE`.
`String`	`getOutputName()` Returns the name of the output collection if the output type is One of `MapReduce.OutputType.REPLACE`, `MapReduce.OutputType.MERGE`, or `MapReduce.OutputType.REDUCE`.
`MapReduce.OutputType`	`getOutputType()` Returns the handling for the output of the map/reduce.
`Document`	`getQuery()` Returns the query to select the documents to run the map/reduce against.
`ReadPreference`	`getReadPreference()` Returns the `ReadPreference` specifying which servers may be used to execute the `MapReduce` command.
`String`	`getReduceFunction()` Returns the reduce function to apply to the emitted output of the map function.
`Document`	`getScope()` Returns the scoped values to expose to the map/reduce/finalize functions.
`Document`	`getSort()` Returns the sort to apply to the input objects.
`boolean`	`isJsMode()` Returns true to limit the translation of the documents to an from BSON/JavaScript.
`boolean`	`isKeepTemp()` Returns true to drop the temporary collections created during the map/reduce.
`boolean`	`isVerbose()` Returns true to emit progress messages in the server logs.

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

- Field Detail
  - MAX_TIMEOUT_VERSION
```
public static final Version MAX_TIMEOUT_VERSION
```
    The first version of MongoDB to support the mapreduce command with the ability to limit the execution time on the server.
- Constructor Detail
  - MapReduce
```
protected MapReduce(MapReduce.Builder builder)
```
    Create a new MapReduce.
    
    Parameters:
    builder - The builder to copy state from.
- Method Detail
  - builder
```
public static MapReduce.Builder builder()
```
    Creates a new builder for a MapReduce.
    
    Returns:
    The builder to construct a MapReduce.
  - getFinalizeFunction
```
public String getFinalizeFunction()
```
    Returns the finalize function to apply to the final results of the reduce function.
    
    Returns:
    The finalize function to apply to the final results of the reduce function.
  - getLimit
```
public int getLimit()
```
    Returns the limit for the number of objects to be used as input to the map/reduce.
    
    Returns:
    The limit for the number of objects to be used as input to the map/reduce.
  - getMapFunction
```
public String getMapFunction()
```
    Returns the map functions to apply to each selected document.
    
    Returns:
    The map functions to apply to each selected document.
  - getMaximumTimeMilliseconds
```
public long getMaximumTimeMilliseconds()
```
    Returns the maximum amount of time to allow the command to run on the Server before it is aborted.
    
    Returns:
    The maximum amount of time to allow the command to run on the Server before it is aborted.
    Since:
    
    MongoDB 2.6
  - getOutputDatabase
```
public String getOutputDatabase()
```
    Returns the name of the output database if the output type is One of MapReduce.OutputType.REPLACE, MapReduce.OutputType.MERGE, or MapReduce.OutputType.REDUCE.
    
    Returns:
    The name of the output database if the output type is One of MapReduce.OutputType.REPLACE, MapReduce.OutputType.MERGE, or MapReduce.OutputType.REDUCE.
  - getOutputName
```
public String getOutputName()
```
    Returns the name of the output collection if the output type is One of MapReduce.OutputType.REPLACE, MapReduce.OutputType.MERGE, or MapReduce.OutputType.REDUCE.
    
    Returns:
    The name of the output collection if the output type is One of MapReduce.OutputType.REPLACE, MapReduce.OutputType.MERGE, or MapReduce.OutputType.REDUCE.
  - getOutputType
```
public MapReduce.OutputType getOutputType()
```
    Returns the handling for the output of the map/reduce.
    
    Returns:
    The handling for the output of the map/reduce.
  - getQuery
```
public Document getQuery()
```
    Returns the query to select the documents to run the map/reduce against.
    
    Returns:
    The query to select the documents to run the map/reduce against.
  - getReadPreference
```
public ReadPreference getReadPreference()
```
    Returns the ReadPreference specifying which servers may be used to execute the MapReduce command.
    If null then the MongoCollection instance's ReadPreference will be used.
    
    NOTE: Passing of read preferences to a mongos does not work in a sharded configuration. The query will always be run on the primary members of all shards.
    
    Returns:
    The read preference to use.
    See Also:
    MongoCollection.getReadPreference()
  - getReduceFunction
```
public String getReduceFunction()
```
    Returns the reduce function to apply to the emitted output of the map function.
    
    Returns:
    The reduce function to apply to the emitted output of the map function.
  - getScope
```
public Document getScope()
```
    Returns the scoped values to expose to the map/reduce/finalize functions.
    
    Returns:
    The scoped values to expose to the map/reduce/finalize functions.
  - getSort
```
public Document getSort()
```
    Returns the sort to apply to the input objects. Useful for optimization, like sorting by the emit key for fewer reduces.
    
    Returns:
    The sort to apply to the input objects. Useful for optimization, like sorting by the emit key for fewer reduces.
  - isJsMode
```
public boolean isJsMode()
```
    Returns true to limit the translation of the documents to an from BSON/JavaScript.
    
    Returns:
    True to limit the translation of the documents to an from BSON/JavaScript.
  - isKeepTemp
```
public boolean isKeepTemp()
```
    Returns true to drop the temporary collections created during the map/reduce.
    
    Returns:
    True to drop the temporary collections created during the map/reduce.
  - isVerbose
```
public boolean isVerbose()
```
    Returns true to emit progress messages in the server logs.
    
    Returns:
    True to emit progress messages in the server logs.

Class MapReduce

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

MAX_TIMEOUT_VERSION

Constructor Detail

MapReduce

Method Detail

builder

getFinalizeFunction

getLimit

getMapFunction

getMaximumTimeMilliseconds

getOutputDatabase

getOutputName

getOutputType

getQuery

getReadPreference

getReduceFunction

getScope

getSort

isJsMode

isKeepTemp

isVerbose