T - the operations result type.public class GroupOperation<T> extends Object implements AsyncReadOperation<AsyncBatchCursor<T>>, ReadOperation<BatchCursor<T>>
| Constructor and Description | 
|---|
| GroupOperation(MongoNamespace namespace,
              BsonJavaScript reduceFunction,
              BsonDocument initial,
              Decoder<T> decoder)Create an operation that will perform a Group on a given collection. | 
| Modifier and Type | Method and Description | 
|---|---|
| GroupOperation<T> | collation(Collation collation)Sets the collation options | 
| BatchCursor<T> | execute(ReadBinding binding)Will return a cursor of Documents containing the results of the group operation. | 
| void | executeAsync(AsyncReadBinding binding,
            SingleResultCallback<AsyncBatchCursor<T>> callback)General execute which can return anything of type T | 
| GroupOperation<T> | filter(BsonDocument filter)Sets the optional query filter to determine which documents in the collection to process. | 
| GroupOperation<T> | finalizeFunction(BsonJavaScript finalizeFunction)Sets the function that runs each item in the result set before returning the final value. | 
| Collation | getCollation()Returns the collation options | 
| Decoder<T> | getDecoder()Gets the decoder used to decode the result documents. | 
| BsonDocument | getFilter()Gets the query filter to determine which documents in the collection to process. | 
| BsonJavaScript | getFinalizeFunction()Gets the function that runs each item in the result before returning the final value. | 
| BsonDocument | getInitial()Gets the initial the aggregation result document. | 
| BsonDocument | getKey()Gets the document containing the field or fields to group. | 
| BsonJavaScript | getKeyFunction()Gets the function that creates a "key object" for use as the grouping key. | 
| MongoNamespace | getNamespace()Gets the namespace. | 
| BsonJavaScript | getReduceFunction()Gets the aggregation function that operates on the documents during the grouping operation. | 
| GroupOperation<T> | key(BsonDocument key)Sets the document containing the field or fields to group. | 
| GroupOperation<T> | keyFunction(BsonJavaScript keyFunction)Sets the function that creates a "key object" for use as the grouping key. | 
public GroupOperation(MongoNamespace namespace, BsonJavaScript reduceFunction, BsonDocument initial, Decoder<T> decoder)
namespace - the database and collection namespace for the operation.reduceFunction - The aggregation function that operates on the documents during the grouping operation.initial - The initial the aggregation result document.decoder - the decoder for the result documents.public MongoNamespace getNamespace()
public Decoder<T> getDecoder()
public BsonDocument getKey()
public GroupOperation<T> key(BsonDocument key)
key - the document containing the field or fields to group.public BsonJavaScript getKeyFunction()
public GroupOperation<T> keyFunction(BsonJavaScript keyFunction)
keyFunction - the function that creates a "key object" for use as the grouping key.public BsonDocument getInitial()
public BsonJavaScript getReduceFunction()
public BsonDocument getFilter()
public GroupOperation<T> filter(BsonDocument filter)
filter - the query filter to determine which documents in the collection to process.public BsonJavaScript getFinalizeFunction()
public GroupOperation<T> finalizeFunction(BsonJavaScript finalizeFunction)
finalizeFunction - the function that runs each item in the result set before returning the final value.public Collation getCollation()
public GroupOperation<T> collation(Collation collation)
A null value represents the server default.
collation - the collation options to usepublic BatchCursor<T> execute(ReadBinding binding)
execute in interface ReadOperation<BatchCursor<T>>binding - the bindingpublic void executeAsync(AsyncReadBinding binding, SingleResultCallback<AsyncBatchCursor<T>> callback)
AsyncReadOperationexecuteAsync in interface AsyncReadOperation<AsyncBatchCursor<T>>binding - the binding to execute in the context ofcallback - the callback to be called when the operation has been executed