Package org.springframework.data.mongodb.core.aggregation

Class UnwindOperation

java.lang.Object

org.springframework.data.mongodb.core.aggregation.UnwindOperation

All Implemented Interfaces:

AggregationOperation, FieldsExposingAggregationOperation, FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation

public class UnwindOperation
extends Object
implements AggregationOperation, FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation

Encapsulates the aggregation framework $unwind-operation.

We recommend to use the static factory method Aggregation.unwind(String) instead of creating instances of this class directly.

Since:

1.3

Author:

Thomas Darimont, Oliver Gierke, Mark Paluch, Christoph Strobl

See Also:

• MongoDB Aggregation Framework: $unwind

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	UnwindOperation.EmptyArraysBuilder
static interface	UnwindOperation.IndexBuilder
static interface	UnwindOperation.PathBuilder
static final class	UnwindOperation.UnwindOperationBuilder	Builder for fluent UnwindOperation creation.

Nested classes/interfaces inherited from interface org.springframework.data.mongodb.core.aggregation.FieldsExposingAggregationOperation

FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation

Constructor Summary

Constructors

Constructor	Description
UnwindOperation(Field field)	Creates a new UnwindOperation for the given Field.
UnwindOperation(Field field, boolean preserveNullAndEmptyArrays)	Creates a new UnwindOperation using Mongo 3.2 syntax.
UnwindOperation(Field field, Field arrayIndex, boolean preserveNullAndEmptyArrays)	Creates a new UnwindOperation using Mongo 3.2 syntax.

Method Summary

Modifier and Type	Method	Description
ExposedFields	getFields()	Returns the fields exposed by the AggregationOperation.
String	getOperator()	Return the MongoDB operator that is used for this AggregationOperation.
static UnwindOperation.PathBuilder	newUnwind()	Get a builder that allows creation of LookupOperation.
org.bson.Document	toDocument(AggregationOperationContext context)	Turns the AggregationOperation into a Document by using the given AggregationOperationContext.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.data.mongodb.core.aggregation.AggregationOperation

toPipelineStages

Methods inherited from interface org.springframework.data.mongodb.core.aggregation.FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation

inheritsFields

Constructor Details

UnwindOperation

public UnwindOperation(Field field)

Creates a new UnwindOperation for the given Field.

Parameters:

field - must not be null.

UnwindOperation

public UnwindOperation(Field field,
 boolean preserveNullAndEmptyArrays)

Creates a new UnwindOperation using Mongo 3.2 syntax.

Parameters:

field - must not be null.

preserveNullAndEmptyArrays - true to output the document if path is null, missing or array is empty.

Since:

1.10

UnwindOperation

public UnwindOperation(Field field,
 Field arrayIndex,
 boolean preserveNullAndEmptyArrays)

Creates a new UnwindOperation using Mongo 3.2 syntax.

Parameters:

field - must not be null.

arrayIndex - optional field name to expose the field array index, must not be null.

preserveNullAndEmptyArrays - true to output the document if path is null, missing or array is empty.

Since:

1.10

Method Details

toDocument

public org.bson.Document toDocument(AggregationOperationContext context)

Description copied from interface: AggregationOperation

Turns the AggregationOperation into a Document by using the given AggregationOperationContext.

Specified by:

toDocument in interface AggregationOperation

Parameters:

context - the AggregationOperationContext to operate within. Must not be null.

Returns:

the Document

getOperator

public String getOperator()

Description copied from interface: AggregationOperation

Return the MongoDB operator that is used for this AggregationOperation. Aggregation operations should implement this method to avoid document rendering.

Specified by:

getOperator in interface AggregationOperation

Returns:

the operator used for this AggregationOperation.

getFields

public ExposedFields getFields()

Description copied from interface: FieldsExposingAggregationOperation

Returns the fields exposed by the AggregationOperation.

Specified by:

getFields in interface FieldsExposingAggregationOperation

Returns:

will never be null.

newUnwind

public static UnwindOperation.PathBuilder newUnwind()

Get a builder that allows creation of LookupOperation.

Returns:

Since:

1.10