Class ArrayOperators.First
java.lang.Object
org.springframework.data.mongodb.core.aggregation.ArrayOperators.First
- All Implemented Interfaces:
AggregationExpression
,MongoExpression
- Enclosing class:
- ArrayOperators
AggregationExpression
for $first
that returns the first element in an array. NOTE: Requires MongoDB 4.4 or later.
- Since:
- 3.4
- Author:
- Divya Srivastava, Christoph Strobl
-
Method Summary
Modifier and TypeMethodDescriptionappend
(Object value, org.springframework.data.mongodb.core.aggregation.AbstractAggregationExpression.Expand expandList) Append the given key at the position in the underlyingLinkedHashMap
.Get the argument map.protected boolean
Check if the given key is available.static ArrayOperators.First
Returns the first element in the given array.static ArrayOperators.First
Returns the first element in the array pointed to by the givenfield reference
.static ArrayOperators.First
firstOf
(AggregationExpression expression) Returns the first element of the array computed by the givenexpression
.protected <T> T
get
(int index) Get the value at a given index.protected <T> T
Get the value for a given key.protected String
protected boolean
org.bson.Document
toDocument
(Object value, AggregationOperationContext context) org.bson.Document
toDocument
(AggregationOperationContext context) values()
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.AggregationExpression
toDocument
-
Method Details
-
first
Returns the first element in the given array.- Parameters:
array
- must not be null.- Returns:
- new instance of
ArrayOperators.First
.
-
firstOf
Returns the first element in the array pointed to by the givenfield reference
.- Parameters:
fieldReference
- must not be null.- Returns:
- new instance of
ArrayOperators.First
.
-
firstOf
Returns the first element of the array computed by the givenexpression
.- Parameters:
expression
- must not be null.- Returns:
- new instance of
ArrayOperators.First
.
-
getMongoMethod
-
toDocument
Description copied from interface:AggregationExpression
- Specified by:
toDocument
in interfaceAggregationExpression
- Parameters:
context
- must not be null.- Returns:
- the MongoDB native (
Document
) form of the expression.
-
toDocument
-
asFields
-
append
-
append
-
append
-
appendTo
-
remove
-
appendAt
Append the given key at the position in the underlyingLinkedHashMap
.- Parameters:
index
-key
-value
-- Returns:
- Since:
- 3.1
-
values
-
get
protected <T> T get(int index) Get the value at a given index.- Type Parameters:
T
-- Parameters:
index
-- Returns:
- Since:
- 2.1
-
get
Get the value for a given key.- Type Parameters:
T
-- Parameters:
key
-- Returns:
- Since:
- 2.1
-
isArgumentMap
protected boolean isArgumentMap() -
argumentMap
Get the argument map.- Returns:
- Since:
- 2.1
-
contains
Check if the given key is available.- Parameters:
key
-- Returns:
- Since:
- 2.1
-