public class PreGeneralizedDataStoreFactory extends Object implements DataStoreFactorySpi
- Christian Mueller
RepositoryClassName (String,mandatory) Name of a class implementing
GeneralizationInfosProviderClassName (String,mandatory) Name of a class implementing
GeneralizationInfosProviderProviderParam (Object,optional) Parameter object for
Constructors Constructor Description
All Methods Instance Methods Concrete Methods Modifier and Type Method Description
canProcess(Map<String,?> params)Test to see if this factory is suitable for processing the data pointed to by the params map.
createDataStore(Map<String,?> params)Construct a live data source using the params specifed.
getDescription()Describe the nature of the datasource constructed by this factory.
getDisplayName()Name suitable for display to end user.
getImplementationHints()Map of hints (maybe unmodifiable) used by this factory to customize its use.
getParametersInfo()MetaData about the required Parameters (for createDataStore).
isAvailable()Test to see if the implementation is available for use.
public static final DataAccessFactory.Param REPOSITORY_CLASS
public static final DataAccessFactory.Param GENERALIZATION_INFOS_PROVIDER_CLASS
public static final DataAccessFactory.Param GENERALIZATION_INFOS_PROVIDER_PARAM
public static final DataAccessFactory.Param NAMESPACEP
public DataStore createDataStore(Map<String,?> params) throws IOExceptionDescription copied from interface:
DataStoreFactorySpiConstruct 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.
- Specified by:
- Specified by:
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
- 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.
IOException- if there were any problems setting up (creating or connecting) the datasource.
public DataStore createNewDataStore(Map<String,?> params) throws IOException
public boolean canProcess(Map<String,?> params)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.
public String getDescription()Describe the nature of the datasource constructed by this factory.
A non localized description of this data store type.
public String getDisplayName()Name suitable for display to end user.
A non localized display name for this data store type.
public DataAccessFactory.Param getParametersInfo()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();
public boolean isAvailable()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
trueas 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.
public Map<RenderingHints.Key,?> getImplementationHints()Description copied from interface:
FactoryMap 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.
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
FactoryRegistryin order to compare this factory's hints against user's hints. This is dependency introspection only;
FactoryRegistrynever invokes this method for creating new factories.
Keys are usually static constants from the
Hintsclass, 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
FactoryRegistryto 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
Classobject, 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;