com.devexperts.qd

Interface DataProvider

All Known Subinterfaces:

QDAgent, RecordProvider

All Known Implementing Classes:

AbstractRecordProvider, CompositeRecordProvider, DataBuffer, RecordBuffer

public interface DataProvider

The DataProvider allows retrieval of accumulated data. See DataVisitor and DataListener for description of corresponding contracts.

Legacy interface

FUTURE DEPRECATION NOTE: New code shall not implement this interface due to its complexity and inherent slowness. Extend AbstractRecordProvider or use RecordBuffer as a high-performance implementation of it when data is available in advance. New code is also discouraged from using this interface unless it is need for interoperability with legacy code. Various legacy APIs will be gradually migrated to NG interfaces and classes.

Method Summary

Modifier and Type	Method and Description
boolean	retrieveData(DataVisitor visitor) Retrieves accumulated data into specified data visitor.
void	setDataListener(DataListener listener) Sets new data listener to receive notifications about data.

Method Detail

retrieveData

boolean retrieveData(DataVisitor visitor)

Retrieves accumulated data into specified data visitor. Returns true if some data still remains in the provider or false if all accumulated data were retrieved.

setDataListener

void setDataListener(DataListener listener)

Sets new data listener to receive notifications about data. Only one listener at a time is supported; the former listener is discarded. Use null to set empty data listener (no notifications).

NOTE: if there is accumulated data available, then specified listener will be notified by this method.