uk.org.ogsadai.dataresource
Class DataResourceAccessorFactory

java.lang.Object
  |
  +--uk.org.ogsadai.dataresource.DataResourceAccessorFactory

public class DataResourceAccessorFactory

extends java.lang.Object

Factory to create data resource accessors.

Data resource accessor classes are specified within a data resource accessor class configuration file (dataResourceClassConfig.xml) within the configuration files directory of the data service resource that is to use the accessor. The class specified must implement the PersistedDataResourceAccessor interface.

Author:

The OGSA-DAI Project Team

COPYRIGHT_NOTICE

private static final java.lang.String COPYRIGHT_NOTICE

See Also:

Constant Field Values

LOG

private static DAILogger LOG

mStaticResourceFactory

private static DataResourceAccessorFactory mStaticResourceFactory

CLASS_CONFIG_FILENAME

private static final java.lang.String CLASS_CONFIG_FILENAME

See Also:

Constant Field Values

DataResourceAccessorFactory

private DataResourceAccessorFactory()

Private constructor.

Use getInstance() to obtain an instance of this class.

getInstance

public static DataResourceAccessorFactory getInstance()

Gets the singleton instance of this class.

Returns:

data resource accessor factory.

createDataResourceAccessor

public DataResourceAccessor createDataResourceAccessor(java.lang.String name,
                                                       java.io.File configDirectory)
                                                throws DataResourceAccessorConfigException,
                                                       DataResourceAccessorCreationException,
                                                       DataResourceAccessorMetaDataException,
                                                       DataResourceAccessorSetupException

Creates a new data resource accessor.

The class implementing the data resource accessor is found within a dataResourceClassConfig.xml file in the given directory.

Parameters:

name - Name of the data service resource that will use this data resource accessor.

configDirectory - The directory containing the configuration files for the data service resource.

Returns:

a configured instance of the data resource accessor.

Throws:

DataResourceAccessorCreationException - if there is a problem in reading the data resource accessor configuration file or creating an instance of the data resource accessor.

DataResourceAccessorConfigException - if an error occurs reading the configuration files for the data resource accessor instance.

DataResourceAccessorMetaDataException - if an error occurs when constructing data resource accessor meta data properties.

DataResourceAccessorSetupException - if an error occurs when setting up the data resource accessor after having read the configuration files.

getDataResourceClassName

private java.lang.String getDataResourceClassName(java.lang.String name,
                                                  java.io.File configDirectory)
                                           throws DataResourceAccessorCreationException

Gets the name of a data resource accessor class from a data resource accessor class configuration file.

Parameters:

name - Name of the data service resource that will use this data resource accessor.

configDirectory - Directory holding data service resource configuration files including the data resource accessor class configuration file.

Returns:

the data resource accessor class name.

Throws:

DataResourceAccessorCreationException - if there is a problem in reading the data resource accessor configuration file.

createDataResourceAccessorInstance

private DataResourceAccessor createDataResourceAccessorInstance(java.lang.String name,
                                                                java.lang.String className)
                                                         throws DataResourceAccessorCreationException

Creates a new DataResourceAccessor object which is an instance of the given class name. The specified class must implement the DataResourceAccessor interface.

Parameters:

name - Name of the data service resource that will use this data resource accessor.

className - Name of data resource accessor class. This class must implement the DataResourceAccessor interface.

Returns:

a newly created instance of the specified class.

Throws:

DataResourceAccessorCreationException - if an instance of the data resource accessor cannot be created.