org.geotools.data.gen

Class PreGeneralizedDataStoreFactory

Object

PreGeneralizedDataStoreFactory

All Implemented Interfaces:

DataAccessFactory, DataStoreFactorySpi, Factory

public class PreGeneralizedDataStoreFactory
extends Object
implements DataStoreFactorySpi

Author:

Christian Mueller

Factory for PreGeneralizedDataStore objects.

Params

RepositoryClassName (String,mandatory) Name of a class implementing Repository

GeneralizationInfosProviderClassName (String,mandatory) Name of a class implementing GeneralizationInfosProvider

GeneralizationInfosProviderProviderParam (Object,optional) Parameter object for GeneralizationInfosProvider.getGeneralizationInfos(Object)

Nested Class Summary

Nested classes/interfaces inherited from interface DataAccessFactory

DataAccessFactory.Param

Field Summary

Fields

Modifier and Type	Field and Description
static DataAccessFactory.Param	GENERALIZATION_INFOS_PROVIDER_CLASS
static DataAccessFactory.Param	GENERALIZATION_INFOS_PROVIDER_PARAM
static DataAccessFactory.Param	NAMESPACEP
static DataAccessFactory.Param	REPOSITORY_CLASS

Constructor Summary

Constructors

Constructor and Description
PreGeneralizedDataStoreFactory()

Method Summary

Modifier and Type	Method and Description
boolean	canProcess(Map<String,Serializable> params) Test to see if this factory is suitable for processing the data pointed to by the params map.
DataStore	createDataStore(Map<String,Serializable> params) Construct a live data source using the params specifed.
DataStore	createNewDataStore(Map<String,Serializable> params)
String	getDescription() Describe the nature of the datasource constructed by this factory.
String	getDisplayName() Name suitable for display to end user.
Map<RenderingHints.Key,?>	getImplementationHints() Map of hints (maybe unmodifiable) used by this factory to customize its use.
DataAccessFactory.Param[]	getParametersInfo() MetaData about the required Parameters (for createDataStore).
boolean	isAvailable() Test to see if the implementation is available for use.

Methods inherited from class Object

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

Field Detail

REPOSITORY_CLASS

public static final DataAccessFactory.Param REPOSITORY_CLASS

GENERALIZATION_INFOS_PROVIDER_CLASS

public static final DataAccessFactory.Param GENERALIZATION_INFOS_PROVIDER_CLASS

GENERALIZATION_INFOS_PROVIDER_PARAM

public static final DataAccessFactory.Param GENERALIZATION_INFOS_PROVIDER_PARAM

NAMESPACEP

public static final DataAccessFactory.Param NAMESPACEP

Constructor Detail

PreGeneralizedDataStoreFactory

public PreGeneralizedDataStoreFactory()

Method Detail

createDataStore

public DataStore createDataStore(Map<String,Serializable> params)
                          throws IOException

Description copied from interface: DataStoreFactorySpi

Construct a live data source using the params specifed.

You can think of this as setting up a connection to the back end data source.

Magic Params: the following params are magic and are honoured by convention by the GeoServer and uDig application.

• "user": is taken to be the user name
• "passwd": is taken to be the password
• "namespace": is taken to be the namespace prefix (and will be kept in sync with GeoServer namespace management.

When we eventually move over to the use of OpperationalParam we will have to find someway to codify this convention.

Specified by:

createDataStore in interface DataAccessFactory

Specified by:

createDataStore in interface DataStoreFactorySpi

Parameters:

params - The full set of information needed to construct a live data store. Typical key values for the map include: url - location of a resource, used by file reading datasources. dbtype - the type of the database to connect to, e.g. postgis, mysql

Returns:

The created DataStore, this may be null if the required resource was not found or if insufficent parameters were given. Note that canProcess() should have returned false if the problem is to do with insuficent parameters.

Throws:

IOException - if there were any problems setting up (creating or connecting) the datasource.

createNewDataStore

public DataStore createNewDataStore(Map<String,Serializable> params)
                             throws IOException

Specified by:

createNewDataStore in interface DataStoreFactorySpi

Throws:

IOException

canProcess

public boolean canProcess(Map<String,Serializable> params)

Description copied from interface: DataAccessFactory

Test to see if this factory is suitable for processing the data pointed to by the params map.

If this datasource requires a number of parameters then this mehtod should check that they are all present and that they are all valid. If the datasource is a file reading data source then the extentions or mime types of any files specified should be checked. For example, a Shapefile datasource should check that the url param ends with shp, such tests should be case insensative.

Specified by:

canProcess in interface DataAccessFactory

Parameters:

params - The full set of information needed to construct a live data source.

Returns:

booean true if and only if this factory can process the resource indicated by the param set and all the required params are pressent.

getDescription

public String getDescription()

Description copied from interface: DataAccessFactory

Describe the nature of the datasource constructed by this factory.

A non localized description of this data store type.

Specified by:

getDescription in interface DataAccessFactory

Returns:

A human readable description that is suitable for inclusion in a list of available datasources.

getDisplayName

public String getDisplayName()

Description copied from interface: DataAccessFactory

Name suitable for display to end user.

A non localized display name for this data store type.

Specified by:

getDisplayName in interface DataAccessFactory

Returns:

A short name suitable for display in a user interface.

getParametersInfo

public DataAccessFactory.Param[] getParametersInfo()

Description copied from interface: DataAccessFactory

MetaData about the required Parameters (for createDataStore).

Interpretation of FeatureDescriptor values:

• getDisplayName(): Gets the localized display name of this feature.
• getName(): Gets the programmatic name of this feature (used as the key in params)
• getShortDescription(): Gets the short description of this feature.

This should be the same as:

 Object params = factory.getParameters();
 BeanInfo info = getBeanInfo( params );

 return info.getPropertyDescriptors();
 

Specified by:

getParametersInfo in interface DataAccessFactory

Returns:

Param array describing the Map for createDataStore

isAvailable

public boolean isAvailable()

Description copied from interface: DataAccessFactory

Test to see if the implementation is available for use. This method ensures all the appropriate libraries to construct the DataAccess are available.

Most factories will simply return true as GeoTools will distribute the appropriate libraries. Though it's not a bad idea for DataStoreFactories to check to make sure that the libraries are there.

OracleDataStoreFactory is an example of one that may generally return false, since GeoTools can not distribute the oracle jars. (they must be added by the client.)

One may ask how this is different than canProcess, and basically available is used by the DataStoreFinder getAvailableDataStore method, so that DataStores that can not even be used do not show up as options in gui applications.

Specified by:

isAvailable in interface DataAccessFactory

Returns:

true if and only if this factory has all the appropriate jars on the classpath to create DataStores.

getImplementationHints

public Map<RenderingHints.Key,?> getImplementationHints()

Description copied from interface: Factory

Map of hints (maybe unmodifiable) used by this factory to customize its use. This map is not guaranteed to contains all the hints supplied by the user; it may be only a subset. Consequently, hints provided here are usually not suitable for creating new factories, unless the implementation make some additional garantees (e.g. FactoryUsingVolatileDependencies).

The primary purpose of this method is to determine if an existing factory instance can be reused for a set of user-supplied hints. This method is invoked by FactoryRegistry in order to compare this factory's hints against user's hints. This is dependency introspection only; FactoryRegistry never invokes this method for creating new factories.

Keys are usually static constants from the Hints class, while values are instances of some key-dependent class. The key set must contains at least all hints impacting functionality. While the key set may contains all hints supplied by the user, it is recommended to limit the set to only the hints used by this particular factory instance. A minimal set will helps FactoryRegistry to compare only hints that matter and avoid the creation of unnecessary instances of this factory.

The hint values may be different than the one supplied by the user. If a user supplied a hint as a Class object, this method shall replace it by the actual instance used, if possible.

Implementations of this method are usually quite simple. For example if a datum authority factory uses an ordinary datum factory, its method could be implemented as below (note that we should not check if the datum factory is null, since key with null value is the expected behaviour in this case). Example:

 Map hints = new HashMap();
 hints.put(Hints.DATUM_FACTORY, datumFactory);
 return hints;
 

Specified by:

getImplementationHints in interface Factory

Returns:

The map of hints, or an empty map if none.