org.springframework.data.mongodb.core.aggregation

Class ProjectionOperation

java.lang.Object

org.springframework.data.mongodb.core.aggregation.ProjectionOperation

All Implemented Interfaces:

AggregationOperation, FieldsExposingAggregationOperation

public class ProjectionOperation
extends Object
implements FieldsExposingAggregationOperation

Encapsulates the aggregation framework $project-operation. Projection of field to be used in an Aggregation. A projection is similar to a Field inclusion/exclusion but more powerful. It can generate new fields, change values of given field etc.

Since:

1.3

Author:

Tobias Trelle, Thomas Darimont, Oliver Gierke

See Also:

http://docs.mongodb.org/manual/reference/aggregation/project/

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ProjectionOperation.ExpressionProjectionOperationBuilder An ProjectionOperation.ProjectionOperationBuilder that is used for SpEL expression based projections.
static class	ProjectionOperation.ProjectionOperationBuilder Builder for ProjectionOperations on a field.

Constructor Summary

Constructors

Constructor and Description
ProjectionOperation() Creates a new empty ProjectionOperation.
ProjectionOperation(Fields fields) Creates a new ProjectionOperation including the given Fields.

Method Summary

Modifier and Type	Method and Description
ProjectionOperation.ProjectionOperationBuilder	and(String name) Creates a new ProjectionOperation.ProjectionOperationBuilder to define a projection for the field with the given name.
ProjectionOperation	andExclude(String... fieldNames) Excludes the given fields from the projection.
ProjectionOperation.ExpressionProjectionOperationBuilder	andExpression(String expression, Object... params)
ProjectionOperation	andInclude(Fields fields) Includes the given fields into the projection.
ProjectionOperation	andInclude(String... fieldNames) Includes the given fields into the projection.
ExposedFields	getFields() Returns the fields exposed by the AggregationOperation.
com.mongodb.DBObject	toDBObject(AggregationOperationContext context) Turns the AggregationOperation into a DBObject by using the given AggregationOperationContext.

Methods inherited from class java.lang.Object

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

Constructor Detail

ProjectionOperation

public ProjectionOperation()

Creates a new empty ProjectionOperation.

ProjectionOperation

public ProjectionOperation(Fields fields)

Creates a new ProjectionOperation including the given Fields.

Parameters:

fields - must not be null.

Method Detail

and

public ProjectionOperation.ProjectionOperationBuilder and(String name)

Creates a new ProjectionOperation.ProjectionOperationBuilder to define a projection for the field with the given name.

Parameters:

name - must not be null or empty.

Returns:

andExpression

public ProjectionOperation.ExpressionProjectionOperationBuilder andExpression(String expression,
                                                                              Object... params)

andExclude

public ProjectionOperation andExclude(String... fieldNames)

Excludes the given fields from the projection.

Parameters:

fieldNames - must not be null.

Returns:

andInclude

public ProjectionOperation andInclude(String... fieldNames)

Includes the given fields into the projection.

Parameters:

fieldNames - must not be null.

Returns:

andInclude

public ProjectionOperation andInclude(Fields fields)

Includes the given fields into the projection.

Parameters:

fields - must not be null.

Returns:

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.

toDBObject

public com.mongodb.DBObject toDBObject(AggregationOperationContext context)

Description copied from interface: AggregationOperation

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

Specified by:

toDBObject in interface AggregationOperation

Returns:

the DBObject