i3.dragos.core.services.datasources
Class DataSourceFactory

java.lang.Object
  i3.dragos.core.AbstractService
      i3.dragos.core.services.datasources.DataSourceFactory

All Implemented Interfaces:

Service

public class DataSourceFactory
extends AbstractService

The DataSourceFactory creates data sources. A data source must be opened after it is obtained from the factory to make it usable.

Data source are identified by two so called datasource URLs, the physical and the logical URL.
The identifier of the physical URL is used to associate a database with a data source implementation. Since some implementations for a data source can be used for different databases like the implementation for JDBC compliant databases wildcards can be used for a database identifier in the configuration file. Hence a "*" is not allowed in database identifiers which are used to obtain a data source from the factory.

Author:

Boris Boehlen <boehlen@cs.rwth-aachen.de>, Thorsten Hermes <thermes@i3.informatik.rwth-aachen.de>

See Also:

DataSourceURL, DataSource

Nested Class Summary

Nested classes/interfaces inherited from interface i3.dragos.core.Service

Service.Result, Service.State

Constructor Summary

DataSourceFactory()
Constructs the factory.

Method Summary

DataSource	create(DataSourceURL physicalDSURL, DataSourceURL logicalDSURL) Creates a new data source.
DataSource	get(DataSourceURL datasourceURL) Retrieves a previously created DataSource by its logical DataSourceURL.
DataSource	get(java.lang.String datasourceURL) Retrieves a previously created DataSource by the String representation of its logical DataSourceURL.
static DataSourceFactory	getInstance() Returns the data source factroy registered by the service manager.
java.lang.String	getName() Returns the name of the service.
java.util.Set<java.lang.String>	getSupportedDataSources() Returns the data source identifiers supported by the factory.
Service.Result	initialize() Initializes the services.
void	registerDataSourceImplementation(java.lang.String id, java.lang.String impl) Registers an implementation for a specific data source.
Service.Result	uninitialize() Uninitializes the services and releases all resources used by the service.

Methods inherited from class i3.dragos.core.AbstractService

getState, resume, start, stop, suspend

Methods inherited from class java.lang.Object

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

Constructor Detail

DataSourceFactory

public DataSourceFactory()

Constructs the factory.

Method Detail

getInstance

public static DataSourceFactory getInstance()

Returns the data source factroy registered by the service manager.

Returns:

the data source factroy registered by the service manager.

getName

public java.lang.String getName()

Returns the name of the service.

Returns:

the name of the service.

initialize

public Service.Result initialize()

Initializes the services.

Specified by:

initialize in interface Service

Overrides:

initialize in class AbstractService

Returns:

OK if the initialization was successful, FAILED if it was not and INVALID if the configuration was incorrect.

uninitialize

public Service.Result uninitialize()

Uninitializes the services and releases all resources used by the service.

Specified by:

uninitialize in interface Service

Overrides:

uninitialize in class AbstractService

Returns:

OK if the uninitialization was successful, FAILED if it was not and INVALID if the configuration was incorrect.

getSupportedDataSources

public java.util.Set<java.lang.String> getSupportedDataSources()

Returns the data source identifiers supported by the factory.

Returns:

A set of identifiers of type String.

registerDataSourceImplementation

public void registerDataSourceImplementation(java.lang.String id,
                                             java.lang.String impl)

Registers an implementation for a specific data source.

Parameters:

id - The data source ID.

impl - The full-qualified name of the realization class.

get

public DataSource get(java.lang.String datasourceURL)
               throws DataSourceFactoryException,
                      java.net.MalformedURLException

Retrieves a previously created DataSource by the String representation of its logical DataSourceURL.

Parameters:

datasourceURL - The URL that identifies the data source.

Returns:

the requested data source

Throws:

DataSourceFactoryException - if the requested data source does not exist.

java.net.MalformedURLException - if the data source URL does not match the syntax specified in DataSourceURL.

get

public DataSource get(DataSourceURL datasourceURL)
               throws DataSourceFactoryException

Retrieves a previously created DataSource by its logical DataSourceURL.

Parameters:

datasourceURL - The URL that identifies the data source.

Returns:

the requested data source

Throws:

DataSourceFactoryException - if the requested data source does not exist.

create

public DataSource create(DataSourceURL physicalDSURL,
                         DataSourceURL logicalDSURL)
                  throws DataSourceFactoryException

Creates a new data source. You can not create more than one data source object for the same physical DataSourceURL (as that would require additional precautions for the DataSource implementations, and is not really useful). You also can obviously not use the same logical DataSourceURL for two different DataSources. Thus, this method behaves as follows:

• both DataSourceURLs were not used before => create a new DataSource
• the same parameters were used in a previous call => return the existing DataSource
• otherwise => throw an exception

Parameters:

physicalDSURL - The physical DataSourceURL that is needed to create the data source (must not be null).

logicalDSURL - The logical DataSourceURL that will identify the data source from now on (must not be null).

Returns:

a data source which can be used to access the requested database

Throws:

DataSourceFactoryException - if something went wrong during the creation of a proper data source.