org.geotools.data.vpf

Class VPFDataStoreFactory

Object

VPFDataStoreFactory

All Implemented Interfaces:

DataAccessFactory, DataStoreFactorySpi, Factory

public class VPFDataStoreFactory
extends Object
implements DataStoreFactorySpi

Class VPFDataSourceFactory.java is responsible for constructing appropriate VPFDataStore (actually VPFLibrary) objects. VPFDataStoreFactory - factory for VPFLibrary - factory for VPFCoverage - factory for VPFFeatureClass - implements FeatureType by delegation to contained DefaultFeatureType - contains VPFFiles - retrieves VPFColumns from VPFFiles for use in constructing DefaultFeatureType - contains joins (column pairs) - factory for VPFFeatureType - implements FeatureType by delegation to contained VPFFeatureClass

VPFFile - contains VPFInputStream - factory for VPFColumn - implements AttributeType by delegation to contained DefaultFeatureType

Created: Fri Mar 28 15:54:32 2003

Author:

Artur Hefczyc, Knut-Erik Johnsen, Project OneMap, Chris Holmes, Fulbright

Nested Class Summary

Nested classes/interfaces inherited from interface DataAccessFactory

DataAccessFactory.Param

Field Summary

Fields

Modifier and Type	Field and Description
static DataAccessFactory.Param	DIR A parameter which is the directory containing the LHT file
static DataAccessFactory.Param	NAMESPACEP

Constructor Summary

Constructors

Constructor and Description
VPFDataStoreFactory() Default Constructor

Method Summary

Modifier and Type	Method and Description
boolean	canProcess(Map<String,?> params) Test to see if this factory is suitable for processing the data pointed to by the params map.
DataStore	createDataStore(Map<String,?> params) Construct a live data source using the params specifed.
DataStore	createDataStore(URL url)
DataStore	createNewDataStore(Map<String,?> 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() Returns the implementation hints.
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

DIR

public static final DataAccessFactory.Param DIR

A parameter which is the directory containing the LHT file

NAMESPACEP

public static final DataAccessFactory.Param NAMESPACEP

Constructor Detail

VPFDataStoreFactory

public VPFDataStoreFactory()

Default Constructor

Method Detail

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.

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.

canProcess

public boolean canProcess(Map<String,?> 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.

createDataStore

public DataStore createDataStore(Map<String,?> 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.

createDataStore

public DataStore createDataStore(URL url)
                          throws IOException

Throws:

IOException

createNewDataStore

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

Specified by:

createNewDataStore in interface DataStoreFactorySpi

Throws:

IOException

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()

Returns the implementation hints. The default implementation returns en empty map.

Specified by:

getImplementationHints in interface Factory

Returns:

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