org.datanucleus.store.types.geospatial.jdo

Class SpatialHelper

java.lang.Object

org.datanucleus.store.types.geospatial.jdo.SpatialHelper

Direct Known Subclasses:

JgeomSpatialHelper, JtsSpatialHelper, PgSpatialHelper

public class SpatialHelper
extends Object

Helper class to search and access Spatial MetaData. This class wraps some of the spatial functions that datanucleus-spatial offers via JDOQL in "real" Java methods and also adds extended functionality, like reading values from JDO-Metadata and getting CRS (Coordinate Reference System) information from the database.

The datatypes and terminology used in this class is (like most of datanucleus-spatial) heavily based on OGC's Simple Feature specification. See http://www.opengeospatial.org/standards/sfa for details.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	SpatialHelper.QueryExecutor Abstract helper class to execute queries.

Field Summary

Fields

Modifier and Type	Field and Description
protected org.datanucleus.api.jdo.JDOPersistenceManagerFactory	pmf
protected org.datanucleus.store.rdbms.RDBMSStoreManager	storeMgr

Constructor Summary

Constructors

Constructor and Description
SpatialHelper(org.datanucleus.api.jdo.JDOPersistenceManagerFactory pmf) Creates a new SpatialHelper instance for the given PMF.

Method Summary

Modifier and Type	Method and Description
Rectangle2D	calculateBoundsInDatastore(Class pc, String fieldName, javax.jdo.PersistenceManager pm)
protected void	checkValid(Class pc, String fieldName)
Rectangle2D	estimateBoundsFromDatastoreMetadata(Class pc, String fieldName, javax.jdo.PersistenceManager pm) Returns the (estimated) spatial extent, also called bounding box from datastore metadata for the given geometry field.
protected SpatialRDBMSAdapter	getAdapter()
protected org.datanucleus.store.rdbms.table.Column	getColumn(Class pc, org.datanucleus.metadata.AbstractMemberMetaData mmd)
protected org.datanucleus.store.rdbms.table.Column	getColumn(Class pc, String fieldName)
String	getCrsNameForSrid(Class pc, int srid, javax.jdo.PersistenceManager pm) Returns the name of the Coordinate Reference System (CRS) for the given srid.
String	getCrsWktForSrid(Class pc, int srid, javax.jdo.PersistenceManager pm) Returns the description of the Coordinate Reference System (CRS) for the given srid in WKT (Well-Known Text).
Integer	getDimensionFromJdoMetadata(Class pc, String fieldName) Returns the dimension from JDO-Metadata for the given geometry field.
String[]	getGeometryColumnBackedFields(Class pc) Return all field names of the given class that are backed by a geometry column in the database.
protected Integer	getIntegerFromJdoMetadata(Class pc, String fieldName, String extensionKey)
protected org.datanucleus.metadata.MetaDataManager	getMetaDataManager()
Integer	getSridFromDatastoreMetadata(Class pc, String fieldName, javax.jdo.PersistenceManager pm) Returns the srid from datastore metadata for the given geometry field.
Integer	getSridFromJdoMetadata(Class pc, String fieldName) Returns the srid from JDO-Metadata for the given geometry field.
protected org.datanucleus.store.rdbms.table.Table	getTable(Class pc)
protected String	getValueFromJdoMetadata(Class pc, String memberName, String extensionKey)
boolean	isGeometryColumnBackedField(Class pc, String fieldName) Checks whether the given field name for the given class is backed by a geometry column in the database.
protected boolean	isGeometryColumnBackedField(org.datanucleus.store.rdbms.table.Column c)
protected Object	readFirstValueForField(Class pc, String fieldName, javax.jdo.PersistenceManager pm)

Methods inherited from class java.lang.Object

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

Field Detail

pmf

protected org.datanucleus.api.jdo.JDOPersistenceManagerFactory pmf

storeMgr

protected org.datanucleus.store.rdbms.RDBMSStoreManager storeMgr

Constructor Detail

SpatialHelper

public SpatialHelper(org.datanucleus.api.jdo.JDOPersistenceManagerFactory pmf)

Creates a new SpatialHelper instance for the given PMF.

Parameters:

pmf - The PMF, can't be null or closed.

Method Detail

getSridFromJdoMetadata

public Integer getSridFromJdoMetadata(Class pc,
                                      String fieldName)

Returns the srid from JDO-Metadata for the given geometry field. Will return null, if the user has not specified a value in his metadata.

Parameters:

pc - The PersistenceCapapable class

fieldName - Name of the geometry field

Returns:

The srid or null.

See Also:

SpatialRDBMSAdapter.SRID_EXTENSION_KEY

getDimensionFromJdoMetadata

public Integer getDimensionFromJdoMetadata(Class pc,
                                           String fieldName)

Returns the dimension from JDO-Metadata for the given geometry field. Will return null, if the user has not specified a value in his metadata.

Parameters:

pc - The PersistenceCapapable class

fieldName - Name of the geometry field

Returns:

The dimension or null.

See Also:

SpatialRDBMSAdapter.DIMENSION_EXTENSION_KEY

getSridFromDatastoreMetadata

public Integer getSridFromDatastoreMetadata(Class pc,
                                            String fieldName,
                                            javax.jdo.PersistenceManager pm)

Returns the srid from datastore metadata for the given geometry field. Will return null, if the datastore doesn't support such an operation (e.g. MySQL) or if there is no metadata in the datastore available for the given class and field name.

Parameters:

pc - The persistable class

fieldName - Name of the geometry field

pm - PersistenceManager instance that should be used to access the datastore

Returns:

The srid or null.

estimateBoundsFromDatastoreMetadata

public Rectangle2D estimateBoundsFromDatastoreMetadata(Class pc,
                                                       String fieldName,
                                                       javax.jdo.PersistenceManager pm)

Returns the (estimated) spatial extent, also called bounding box from datastore metadata for the given geometry field. Will return null, if the datastore doesn't support such an operation (e.g. MySQL) or if there is no metadata in the datastore available for the given class and field name.

Parameters:

pc - The persistable class

fieldName - Name of the geometry field

pm - PersistenceManager instance that should be used to access the datastore

Returns:

The bbox or null.

calculateBoundsInDatastore

public Rectangle2D calculateBoundsInDatastore(Class pc,
                                              String fieldName,
                                              javax.jdo.PersistenceManager pm)

getCrsWktForSrid

public String getCrsWktForSrid(Class pc,
                               int srid,
                               javax.jdo.PersistenceManager pm)

Returns the description of the Coordinate Reference System (CRS) for the given srid in WKT (Well-Known Text). Will return null, if the datastore doesn't support such an operation (e.g. MySQL) or if there is no metadata in the datastore available for the given class and srid.

Parameters:

pc - The persistable class

srid - The srid

pm - PersistenceManager instance that should be used to access the datastore

Returns:

Description of the CRS in WKT or null.

getCrsNameForSrid

public String getCrsNameForSrid(Class pc,
                                int srid,
                                javax.jdo.PersistenceManager pm)

Returns the name of the Coordinate Reference System (CRS) for the given srid. Will return null, if the datastore doesn't support such an operation (e.g. MySQL) or if there is no metadata in the datastore available for the given class and srid.

Parameters:

pc - The persistable class

srid - The srid

pm - PersistenceManager instance that should be used to access the datastore

Returns:

Name the CRS or null.

getIntegerFromJdoMetadata

protected Integer getIntegerFromJdoMetadata(Class pc,
                                            String fieldName,
                                            String extensionKey)

getValueFromJdoMetadata

protected String getValueFromJdoMetadata(Class pc,
                                         String memberName,
                                         String extensionKey)

getGeometryColumnBackedFields

public String[] getGeometryColumnBackedFields(Class pc)

Return all field names of the given class that are backed by a geometry column in the database.

Parameters:

pc - The persistable class

Returns:

Array of names, may be empty, but never null.

isGeometryColumnBackedField

public boolean isGeometryColumnBackedField(Class pc,
                                           String fieldName)

Checks whether the given field name for the given class is backed by a geometry column in the database.

Parameters:

pc - The persistable class

fieldName - Name of the field

Returns:

true, if the field is backed by a geometry column, false otherwise.

isGeometryColumnBackedField

protected boolean isGeometryColumnBackedField(org.datanucleus.store.rdbms.table.Column c)

getTable

protected org.datanucleus.store.rdbms.table.Table getTable(Class pc)

getColumn

protected org.datanucleus.store.rdbms.table.Column getColumn(Class pc,
                                                             String fieldName)

getColumn

protected org.datanucleus.store.rdbms.table.Column getColumn(Class pc,
                                                             org.datanucleus.metadata.AbstractMemberMetaData mmd)

getAdapter

protected SpatialRDBMSAdapter getAdapter()
                                  throws ClassCastException

Throws:

ClassCastException

getMetaDataManager

protected org.datanucleus.metadata.MetaDataManager getMetaDataManager()

checkValid

protected void checkValid(Class pc,
                          String fieldName)
                   throws IllegalArgumentException,
                          NullPointerException

Throws:

IllegalArgumentException

NullPointerException

readFirstValueForField

protected Object readFirstValueForField(Class pc,
                                        String fieldName,
                                        javax.jdo.PersistenceManager pm)