Package uk.ac.rdg.resc.edal.dataset.cdm

Class CdmDatasetFactory

java.lang.Object

uk.ac.rdg.resc.edal.dataset.DatasetFactory

uk.ac.rdg.resc.edal.dataset.cdm.CdmDatasetFactory

Direct Known Subclasses:

CdmGridDatasetFactory

public abstract class CdmDatasetFactory
extends DatasetFactory

DatasetFactory that creates Datasets representing gridded data read through the Unidata Common Data Model. Although multiple instances of this DatasetFactory can be created, all share a common cache of NetcdfDataset objects to speed up operations where the same dataset is accessed multiple times. To avoid excess file handles being open, this is a LRU cache which closes the datasets when they expire.

Author:

Guy Griffiths

Field Summary

Fields inherited from class uk.ac.rdg.resc.edal.dataset.DatasetFactory

workingDir

Constructor Summary

Constructors

Constructor	Description
CdmDatasetFactory()

Method Summary

Modifier and Type	Method	Description
DiscreteLayeredDataset<? extends DataSource,? extends DiscreteLayeredVariableMetadata>	createDataset(String id, String location)	Returns a Dataset object representing the data at the given location.
DiscreteLayeredDataset<? extends DataSource,? extends DiscreteLayeredVariableMetadata>	createDataset(String id, String location, boolean forceRefresh)	Returns a Dataset object representing the data at the given location.
protected abstract DiscreteLayeredDataset<? extends DataSource,? extends DiscreteLayeredVariableMetadata>	generateDataset(String id, String location, ucar.nc2.dataset.NetcdfDataset nc)	Generate a DiscreteLayeredDataset for the given ID, location, and NetcdfDataset.
protected ucar.nc2.dataset.NetcdfDataset	getNetcdfDatasetFromLocation(String location, boolean forceRefresh)
protected Parameter	getParameter(ucar.nc2.Variable variable)	Generates a Parameter object, correctly parsing categorical flags and creating the Parameter.Categorys associated with the Parameter.
protected static String	getVariableName(ucar.nc2.Variable var)

Methods inherited from class uk.ac.rdg.resc.edal.dataset.DatasetFactory

forName, setDefaultDatasetFactoryClass, setWorkingDirectory

Methods inherited from class java.lang.Object

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

Constructor Detail

CdmDatasetFactory

public CdmDatasetFactory()

Method Detail

createDataset

public DiscreteLayeredDataset<? extends DataSource,? extends DiscreteLayeredVariableMetadata> createDataset(String id,
                                                                                                                  String location)
                                                                                                           throws IOException,
                                                                                                                  EdalException

Description copied from class: DatasetFactory

Returns a Dataset object representing the data at the given location.

Overrides:

createDataset in class DatasetFactory

Parameters:

id - The ID to assign to this dataset

location - The location of the source data: this may be a file, database connection string or a remote server address.

Throws:

EdalException - If there is a problem creating the dataset

IOException

createDataset

public DiscreteLayeredDataset<? extends DataSource,? extends DiscreteLayeredVariableMetadata> createDataset(String id,
                                                                                                                  String location,
                                                                                                                  boolean forceRefresh)
                                                                                                           throws EdalException

Description copied from class: DatasetFactory

Returns a Dataset object representing the data at the given location.

Specified by:

createDataset in class DatasetFactory

Parameters:

id - The ID to assign to this dataset

location - The location of the source data: this may be a file, database connection string or a remote server address.

forceRefresh - Set to true to ensure that any cached information is not used

Throws:

EdalException - If there is a problem creating the dataset

getNetcdfDatasetFromLocation

protected ucar.nc2.dataset.NetcdfDataset getNetcdfDatasetFromLocation(String location,
                                                                      boolean forceRefresh)
                                                               throws IOException,
                                                                      EdalException

Throws:

IOException

EdalException

getParameter

protected Parameter getParameter(ucar.nc2.Variable variable)

Generates a Parameter object, correctly parsing categorical flags and creating the Parameter.Categorys associated with the Parameter. Subclasses should use this method to generate Parameters.

Parameters:

variable - The Variable object representing the variable in the NetCDF file

Returns:

The resulting Parameter

generateDataset

protected abstract DiscreteLayeredDataset<? extends DataSource,? extends DiscreteLayeredVariableMetadata> generateDataset(String id,
                                                                                                                                String location,
                                                                                                                                ucar.nc2.dataset.NetcdfDataset nc)
                                                                                                                         throws IOException

Generate a DiscreteLayeredDataset for the given ID, location, and NetcdfDataset. Subclasses should use this to generate a simple DiscreteLayeredDataset - i.e. one with no additional plugins etc. All required VariablePlugins will be detected and handled by this class.

Parameters:

id - The ID of the Dataset

location - The location of the Dataset (either on disk or online)

nc - The NetcdfDataset representing the Dataset

Returns:

A DiscreteLayeredDataset

Throws:

IOException - If there is a problem reading the underlying NetcdfDataset

getVariableName

protected static String getVariableName(ucar.nc2.Variable var)

Returns:

the name of the phenomenon that the given variable represents. This name will be, in order of preference: The long name The standard name The variable name