Package org.dashbuilder.dataprovider

Interface DataSetProvider

public interface DataSetProvider

This service provider interface is designed to provide access to different data set storage implementations with the main goal of providing a unified interface for the data set fetch & lookup operations.

Method Summary

Modifier and Type	Method	Description
DataSetMetadata	getDataSetMetadata(DataSetDef def)	Retrieves the metadata for a given data set definition
DataSetProviderType	getType()	The type of the provider.
boolean	isDataSetOutdated(DataSetDef def)	Check if the specified data set definition is outdated.
DataSet	lookupDataSet(DataSetDef def, DataSetLookup lookup)	Fetch a data set and optionally apply several operations (filter, sort, group, ...) on top of it.

Method Detail

getType

DataSetProviderType getType()

The type of the provider.

getDataSetMetadata

DataSetMetadata getDataSetMetadata(DataSetDef def)
                            throws Exception

Retrieves the metadata for a given data set definition

Parameters:

def - The data set definition lookup request

Returns:

The data set metadata

Throws:

Exception

lookupDataSet

DataSet lookupDataSet(DataSetDef def,
                      DataSetLookup lookup)
               throws Exception

Fetch a data set and optionally apply several operations (filter, sort, group, ...) on top of it.

For group operations on date columns the grouped column values must stick to the following format:

 GroupStrategy   IntervalType       Output
 ---------------------------------------------------
   DYNAMIC         SECOND        yyyy-MM-dd HH:mm:ss
   DYNAMIC         MINUTE        yyyy-MM-dd HH:mm
   DYNAMIC         HOUR          yyyy-MM-dd HH
   DYNAMIC         DAY           yyyy-MM-dd
   DYNAMIC         MONTH         yyyy-MM
   DYNAMIC         YEAR          yyyy

   yyyy=year                 HH=hour from 00 to 23,
   MM=month from 01 to 12    mm=minutes from 00 to 59
   dd=day from 01 to 31      ss=seconds from 00 to 59

   FIXED           SECOND        From 0 to 59
   FIXED           MINUTE        From 0 to 59
   FIXED           HOUR          From 0 to 23
   FIXED           DAY_OF_WEEK   From 1 to 7 (1=Sunday, 7=Saturday)
   FIXED           MONTH         From 1 to 12 (1=January, 12=December)
   FIXED           QUARTER       From 1 to 4 (1=Ene,Feb,Mar, 4=Oct,Nov,Dec)
 

Parameters:

def - The data set definition lookup request

lookup - The lookup request over the data set. If null then return the data set as is.

Returns:

The resulting data set instance

Throws:

Exception

isDataSetOutdated

boolean isDataSetOutdated(DataSetDef def)

Check if the specified data set definition is outdated. This means that the data set might have been updated at origin. When this happens, any data hold by the provider can be considered stale and a refresh is needed.

Parameters:

def - The data set definition to check for

Returns:

true if the data set has become stale. false otherwise.