com.mongodb.operation

Class DistinctOperation<T>

java.lang.Object

com.mongodb.operation.DistinctOperation<T>

Type Parameters:

T - the type of the distinct value

All Implemented Interfaces:

AsyncReadOperation<AsyncBatchCursor<T>>, ReadOperation<BatchCursor<T>>

public class DistinctOperation<T>
extends Object
implements AsyncReadOperation<AsyncBatchCursor<T>>, ReadOperation<BatchCursor<T>>

Finds the distinct values for a specified field across a single collection.

When possible, the distinct command uses an index to find documents and return values.

Since:

3.0

MongoDB documentation

Distinct Command

Constructor Summary

Constructors

Constructor and Description
DistinctOperation(MongoNamespace namespace, String fieldName, Decoder<T> decoder) Construct an instance.

Method Summary

Methods

Modifier and Type	Method and Description
BatchCursor<T>	execute(ReadBinding binding) General execute which can return anything of type T
void	executeAsync(AsyncReadBinding binding, SingleResultCallback<AsyncBatchCursor<T>> callback) General execute which can return anything of type T
DistinctOperation<T>	filter(BsonDocument filter) Sets the query filter to apply to the query.
BsonDocument	getFilter() Gets the query filter.
long	getMaxTime(TimeUnit timeUnit) Gets the maximum execution time on the server for this operation.
DistinctOperation<T>	maxTime(long maxTime, TimeUnit timeUnit) Sets the maximum execution time on the server for this operation.

Methods inherited from class java.lang.Object

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

Constructor Detail

DistinctOperation

public DistinctOperation(MongoNamespace namespace,
                 String fieldName,
                 Decoder<T> decoder)

Construct an instance.

Parameters:

namespace - the database and collection namespace for the operation.

fieldName - the name of the field to return distinct values.

decoder - the decoder for the result documents.

Method Detail

getFilter

public BsonDocument getFilter()

Gets the query filter.

Returns:

the query filter

MongoDB documentation

Filter

filter

public DistinctOperation<T> filter(BsonDocument filter)

Sets the query filter to apply to the query.

Parameters:

filter - the query filter, which may be null.

Returns:

this

MongoDB documentation

Filter

getMaxTime

public long getMaxTime(TimeUnit timeUnit)

Gets the maximum execution time on the server for this operation. The default is 0, which places no limit on the execution time.

Parameters:

timeUnit - the time unit to return the result in

Returns:

the maximum execution time in the given time unit

maxTime

public DistinctOperation<T> maxTime(long maxTime,
                           TimeUnit timeUnit)

Sets the maximum execution time on the server for this operation.

Parameters:

maxTime - the max time

timeUnit - the time unit, which may not be null

Returns:

this

execute

public BatchCursor<T> execute(ReadBinding binding)

Description copied from interface: ReadOperation

General execute which can return anything of type T

Specified by:

execute in interface ReadOperation<BatchCursor<T>>

Parameters:

binding - the binding to execute in the context of

Returns:

T, the result of the execution

executeAsync

public void executeAsync(AsyncReadBinding binding,
                SingleResultCallback<AsyncBatchCursor<T>> callback)

Description copied from interface: AsyncReadOperation

General execute which can return anything of type T

Specified by:

executeAsync in interface AsyncReadOperation<AsyncBatchCursor<T>>

Parameters:

binding - the binding to execute in the context of

callback - the callback to be called when the operation has been executed