org.springframework.data.mongodb.core.query

Class Field

java.lang.Object

org.springframework.data.mongodb.core.query.Field

public class Field
extends Object

Field projection.

Author:

Thomas Risberg, Oliver Gierke, Patryk Wasik, Christoph Strobl, Mark Paluch, Owen Q

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Field.FieldProjectionExpression Intermediate builder part for projecting a MongoExpression to a result field.

Constructor Summary

Constructors

Constructor and Description
Field()

Method Summary

Modifier and Type	Method and Description
Field	elemMatch(String field, Criteria elemMatchCriteria)
boolean	equals(Object o)
Field	exclude(String... fields) Exclude one or more fields from being returned by the query operation.
Field	exclude(String field) Exclude a single field from being returned by the query operation.
org.bson.Document	getFieldsObject()
int	hashCode()
Field	include(String... fields) Include one or more fields to be returned by the query operation.
Field	include(String field) Include a single field to be returned by the query operation.
Field	position(String field, int value) The array field must appear in the query.
Field.FieldProjectionExpression	project(MongoExpression expression) Project a given MongoExpression to a field included in the result.
Field	projectAs(MongoExpression expression, String field) Project a given MongoExpression to a field included in the result.
Field	slice(String field, int size) Project a $slice of the array field using the first size elements.
Field	slice(String field, int offset, int size) Project a $slice of the array field using the first size elements starting at offset.

Methods inherited from class java.lang.Object

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

Constructor Detail

Field

public Field()

Method Detail

include

public Field include(String field)

Include a single field to be returned by the query operation.

Parameters:

field - the document field name to be included.

Returns:

this field projection instance.

project

public Field.FieldProjectionExpression project(MongoExpression expression)

Project a given MongoExpression to a field included in the result.

 // { 'name' : { '$toUpper' : '$name' } }

 // native MongoDB expression
 .project(MongoExpression.expressionFromString("'$toUpper' : '$name'")).as("name");

 // Aggregation Framework expression
 .project(StringOperators.valueOf("name").toUpper()).as("name");

 // Aggregation Framework SpEL expression
 .project(AggregationSpELExpression.expressionOf("toUpper(name)")).as("name");
 

Parameters:

expression - must not be null.

Returns:

new instance of Field.FieldProjectionExpression. Define the target field name through as(String).

Since:

3.2

projectAs

public Field projectAs(MongoExpression expression,
                       String field)

Project a given MongoExpression to a field included in the result.

 // { 'name' : { '$toUpper' : '$name' } }

 // native MongoDB expression
 .projectAs(MongoExpression.expressionFromString("'$toUpper' : '$name'"), "name");

 // Aggregation Framework expression
 .projectAs(StringOperators.valueOf("name").toUpper(), "name");

 // Aggregation Framework SpEL expression
 .projectAs(AggregationSpELExpression.expressionOf("toUpper(name)"), "name");
 

Parameters:

expression - must not be null.

field - the field name used in the result.

Returns:

new instance of Field.FieldProjectionExpression.

Since:

3.2

include

public Field include(String... fields)

Include one or more fields to be returned by the query operation.

Parameters:

fields - the document field names to be included.

Returns:

this field projection instance.

Since:

3.1

exclude

public Field exclude(String field)

Exclude a single field from being returned by the query operation.

Parameters:

field - the document field name to be included.

Returns:

this field projection instance.

exclude

public Field exclude(String... fields)

Exclude one or more fields from being returned by the query operation.

Parameters:

fields - the document field names to be included.

Returns:

this field projection instance.

Since:

3.1

slice

public Field slice(String field,
                   int size)

Project a $slice of the array field using the first size elements.

Parameters:

field - the document field name to project, must be an array field.

size - the number of elements to include.

Returns:

this field projection instance.

slice

public Field slice(String field,
                   int offset,
                   int size)

Project a $slice of the array field using the first size elements starting at offset.

Parameters:

field - the document field name to project, must be an array field.

offset - the offset to start at.

size - the number of elements to include.

Returns:

this field projection instance.

elemMatch

public Field elemMatch(String field,
                       Criteria elemMatchCriteria)

position

public Field position(String field,
                      int value)

The array field must appear in the query. Only one positional $ operator can appear in the projection and only one array field can appear in the query.

Parameters:

field - query array field, must not be null or empty.

value -

Returns:

this field projection instance.

getFieldsObject

public org.bson.Document getFieldsObject()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object