com.allanbank.mongodb.builder

Class GroupBy.Builder

java.lang.Object

com.allanbank.mongodb.builder.GroupBy.Builder

Enclosing class:

GroupBy

public static class GroupBy.Builder
extends Object

Builder provides a builder for Group commands.

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 ©:

2012, Allanbank Consulting, Inc., All Rights Reserved

Field Summary

Fields

Modifier and Type	Field and Description
protected String	myFinalizeFunction The finalizer function to run for each group.
protected Document	myInitialValue The initial value for the group.
protected String	myKeyFunction Function to return the key for a document.
protected Set<String>	myKeys The fields to group by.
protected Document	myQuery The query to select the documents to run the group against.
protected ReadPreference	myReadPreference The read preference to use.
protected String	myReduceFunction The reduce function taking the previous value and the current value and returning the new reduced value.

Constructor Summary

Constructors

Constructor and Description
GroupBy.Builder() Creates a new Builder.

Method Summary

Methods

Modifier and Type	Method and Description
GroupBy	build() Creates a new GroupBy based on the current state of the builder.
GroupBy.Builder	setFinalizeFunction(String finalizeFunction) Sets the value of the finalizer function to run for each group.
GroupBy.Builder	setInitialValue(DocumentAssignable initialValue) Sets the value of the initial value for the group.
GroupBy.Builder	setKeyFunction(String keyFunction) Sets the value of the function to return the key for a document.
GroupBy.Builder	setKeys(Set<String> keys) Sets the fields to group by
GroupBy.Builder	setQuery(DocumentAssignable query) Sets the value of the query to select the documents to run the group against.
GroupBy.Builder	setReadPreference(ReadPreference readPreference) Sets the ReadPreference specifying which servers may be used to execute the GroupBy command.
GroupBy.Builder	setReduceFunction(String reduceFunction) Sets the value of the reduce function taking the previous value and the current value and returning the new reduced value.

Methods inherited from class java.lang.Object

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

Field Detail

myFinalizeFunction

protected String myFinalizeFunction

The finalizer function to run for each group.

myInitialValue

protected Document myInitialValue

The initial value for the group.

myKeyFunction

protected String myKeyFunction

Function to return the key for a document. Used instead of the setKeys(java.util.Set<java.lang.String>) to dynamically determine the group for each document.

myKeys

protected final Set<String> myKeys

The fields to group by.

myQuery

protected Document myQuery

The query to select the documents to run the group against.

myReadPreference

protected ReadPreference myReadPreference

The read preference to use.

myReduceFunction

protected String myReduceFunction

The reduce function taking the previous value and the current value and returning the new reduced value.

Constructor Detail

GroupBy.Builder

public GroupBy.Builder()

Creates a new Builder.

Method Detail

build

public GroupBy build()
              throws AssertionError

Creates a new GroupBy based on the current state of the builder.

Returns:

A new GroupBy based on the current state of the builder.

Throws:

AssertionError - If neither the keys nor key function have been set.

setFinalizeFunction

public GroupBy.Builder setFinalizeFunction(String finalizeFunction)

Sets the value of the finalizer function to run for each group.

Parameters:

finalizeFunction - The new value for the finalizer function to run for each group.

Returns:

This GroupBy.Builder for method call chaining.

setInitialValue

public GroupBy.Builder setInitialValue(DocumentAssignable initialValue)

Sets the value of the initial value for the group.

Parameters:

initialValue - The new value for the initial value for the group.

Returns:

This GroupBy.Builder for method call chaining.

setKeyFunction

public GroupBy.Builder setKeyFunction(String keyFunction)

Sets the value of the function to return the key for a document. Used instead of the setKeys(java.util.Set<java.lang.String>) to dynamically determine the group for each document.

Parameters:

keyFunction - The new value for the function to return the key for a document. Used instead of the setKeys(java.util.Set<java.lang.String>) to dynamically determine the group for each document.

Returns:

This GroupBy.Builder for method call chaining.

setKeys

public GroupBy.Builder setKeys(Set<String> keys)

Sets the fields to group by

Parameters:

keys - The new fields to group by

Returns:

This GroupBy.Builder for method call chaining.

setQuery

public GroupBy.Builder setQuery(DocumentAssignable query)

Sets the value of the query to select the documents to run the group against.

Parameters:

query - The new value for the query to select the documents to run the group against.

Returns:

This GroupBy.Builder for method call chaining.

setReadPreference

public GroupBy.Builder setReadPreference(ReadPreference readPreference)

Sets the ReadPreference specifying which servers may be used to execute the GroupBy command.

If not set or set to null then the MongoCollection instance's ReadPreference will be used.

Parameters:

readPreference - The read preferences specifying which servers may be used.

Returns:

This builder for chaining method calls.

See Also:

MongoCollection.getReadPreference()

setReduceFunction

public GroupBy.Builder setReduceFunction(String reduceFunction)

Sets the value of the reduce function taking the previous value and the current value and returning the new reduced value.

Parameters:

reduceFunction - The new value for the reduce function taking the previous value and the current value and returning the new reduced value.

Returns:

This GroupBy.Builder for method call chaining.