ilog.views.maps.format.oracle.objectmodel

Class IlvDefaultObjectSDOTileLoader

java.lang.Object

ilog.views.maps.format.oracle.IlvSDOTileLoader

ilog.views.maps.format.oracle.objectmodel.IlvDefaultObjectSDOTileLoader

All Implemented Interfaces:

IlvPersistentObject, IlvTileLoader

public class IlvDefaultObjectSDOTileLoader
extends IlvSDOTileLoader

This class implements an IlvTileLoader to load tiles from Oracle Spatial, using the Oracle Spatial Object Relational Model.
This implementation has some optimizations (the tile grouping capacity, ...). The geometry metadata table that is used through this class is SDO_GEOM_METADATA for Oracle 8.1.5- and USER_SDO_GEOM_METADATA for Oracle 8.1.6+.

The default tile loader loads data from an Oracle Spatial layer. This layer is a regular Oracle table which contains at least a geometry column of type MDSYS.SDO_GEOMETRY. To retrieve data, the tile loader needs to know some parameters available in the geometry metadata table such as the X dimension name (if set to null, the index of the X dimension in the metadata table (in the SDO_DIM_ARRAY) will be considered as 0), the Y dimension name (if set to null, the index of the Y dimension in the metadata table (in the SDO_DIM_ARRAY) will be considered as 1) and possibly, the extent of the layer.

The other parameters such as tile width and tile height define one tile in the tiling grid of the tile loader. And finally, when a key column name is specified and extracted feature IDs are not null, IlvMapFeature belonging to multiple tiles are loaded just once.

Since:

JViews 3.5

See Also:

IlvObjectSDOLayer, IlvSDOTileLoader

Constructor Summary

Constructors

Constructor and Description
IlvDefaultObjectSDOTileLoader(IlvInputStream stream) Reads the tile loader from an IlvInputStream.
IlvDefaultObjectSDOTileLoader(IlvSDOConnection connection, IlvObjectSDOLayerMetaData metadata, double tileWidth, double tileHeight, String xDimensionName, String yDimensionName, IlvObjectSDOKeyExtractor keyExtractor, IlvRect size) The main constructor of IlvDefaultObjectSDOTileLoader.
IlvDefaultObjectSDOTileLoader(IlvSDOConnection connection, String layerName, double tileWidth, double tileHeight, String keyColumnName) Initializes an instance of IlvDefaultObjectSDOTileLoader.

Method Summary

Modifier and Type	Method and Description
void	connectionRestored() This method is called by the IlvSDOLayer when it is read from an .ivl file, and after the connection to an Oracle Spatial database has been restored.
IlvCoordinateSystem	getDefaultCoordinateSystem() Returns the default IlvCoordinateSystem used to render map features when they do not have a specified one.
IlvObjectSDOFeatureIterator	getFeatureIterator(ResultSet resultSet, String geometryName, IlvObjectSDOKeyExtractor keyExtractor, String xDimensionName, String yDimensionName) Returns the instance of IlvObjectSDOFeatureIterator that is used by the tile loader.
int	getFetchSize() Returns the fetch size parameter passed to the setRequestParameters method.
IlvObjectSDOLayerMetaData	getLayerMetaData() Returns the metadata associated to this tile loader.
String	getLayerName() Returns the name of the SDO layer read by this tile loader.
String[]	getRequestParameters() Returns the parameters of the internal request used for load-on-demand.
ResultSet	getResultSet(IlvTile tile) Returns the ResultSet containing the geometries that intersect the specified tile.
IlvRect	getSize() Returns size of the tile loader.
short	getTileGroupingCount() Returns the number of tiles to be loaded in one single Oracle request.
IlvRect	getTileOrigin() Returns the coordinates of the origin tile used by the load-on demand mechanism.
boolean	isClippingRequest() Returns whether the tile loader will perform a strict clipping.
void	load(IlvTile tile) Loads a tile from the Oracle database and adds the graphic objects to the layer of the tile.
void	setClippingRequest(boolean set) Sets whether this tile loader performs a strict clipping.
void	setDefaultCoordinateSystem(IlvCoordinateSystem defaultCoordinateSystem) Sets the default IlvCoordinateSystem used to render map features when they do not have a specified one.
void	setRequestParameters(String selectClause, String fromClause, String whereClause, String spatialOperator, String spatialOperatorParams, int fetchSize) Sets some parameters in order to tune the request that is used by an IlvTile.
void	setTileGroupingCount(short nb) Sets the number of tiles to be loaded in one single Oracle request.
void	write(IlvOutputStream stream) Writes this tile loader to specified stream.

Methods inherited from class ilog.views.maps.format.oracle.IlvSDOTileLoader

executeQuery, getConnection, isPersistent, release

Methods inherited from class java.lang.Object

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

Constructor Detail

IlvDefaultObjectSDOTileLoader

public IlvDefaultObjectSDOTileLoader(IlvSDOConnection connection,
                                     String layerName,
                                     double tileWidth,
                                     double tileHeight,
                                     String keyColumnName)
                              throws SQLException

Initializes an instance of IlvDefaultObjectSDOTileLoader.

The geometries are read from the layer specified by its name. The name of the coordinates of geometries are defaulted to "X" and "Y". The geometry is read from the first column of the database for which the type of data is specified to be SDO_GEOMETRY.

Parameters:

connection - The connection.

layerName - The name of the layer.

tileWidth - The width of one tile, in database units.

tileHeight - The height of one tile, in database units.

keyColumnName - The name of the column containing object ID or null if no ID is associated to features.

Throws:

SQLException

IlvDefaultObjectSDOTileLoader

public IlvDefaultObjectSDOTileLoader(IlvSDOConnection connection,
                                     IlvObjectSDOLayerMetaData metadata,
                                     double tileWidth,
                                     double tileHeight,
                                     String xDimensionName,
                                     String yDimensionName,
                                     IlvObjectSDOKeyExtractor keyExtractor,
                                     IlvRect size)
                              throws SQLException

The main constructor of IlvDefaultObjectSDOTileLoader.

The geometries are read from the layer specified by its name. Geometries are extracted from the column whose name is specified. Feature IDs are extracted using the specified IlvObjectSDOKeyExtractor.

The extent of the whole layer (that is, the rectangle containing all geometries of the layer) is generally kept up-to-date (by the user) in the geometry metadata table of the Oracle Spatial Database. However, in some cases, providing a more accurate extent (like the extent returned using SDO_TUNE.EXTENT_OF) can lead to much better performances.

Parameters:

connection - The IlvSDOConnection to an Oracle Data Base with the Spatial extensions.

metadata - The metadata of the layer to be loaded on demand.

tileWidth - The width of one tile, in database units.

tileHeight - The height of one tile, in database units.

xDimensionName - The name of the x-dimension.

yDimensionName - The name of the y-dimension.

keyExtractor - The key extractor to extract feature IDs.

size - The size of the layer. If set to null, the size is defaulted to the one available in the geometry metadata table.

Throws:

SQLException

Since:

JViews 5.5

See Also:

IlvObjectSDOUtil.GetLayerExtent(java.sql.Connection, java.lang.String, java.lang.String, java.lang.String, java.lang.String, boolean), IlvObjectSDOLayerMetaData, IlvDefaultObjectSDOKeyExtractor

IlvDefaultObjectSDOTileLoader

public IlvDefaultObjectSDOTileLoader(IlvInputStream stream)
                              throws IlvReadFileException

Reads the tile loader from an IlvInputStream.

Parameters:

stream - The input stream.

Throws:

IlvReadFileException - if an error occurs while reading.

Method Detail

setClippingRequest

public void setClippingRequest(boolean set)

Sets whether this tile loader performs a strict clipping. When the strict clipping mode is set, the loaded geometries are clipped so that they intersect the bounding box of the IlvTile that has loaded them. The default behavior of this tile loader is to not perform this strict clipping.

Parameters:

set - If true, the strict clipping mode is set.

See Also:

isClippingRequest()

isClippingRequest

public boolean isClippingRequest()

Returns whether the tile loader will perform a strict clipping. When the strict clipping mode is set, the loaded geometries are clipped so that they intersect the bounding box of the IlvTile that has loaded them. The default behavior of this tile loader is to not perform this strict clipping.

Returns:

true if this tile loader clips strictly the geometries.

See Also:

setClippingRequest(boolean)

getLayerName

public String getLayerName()

Returns the name of the SDO layer read by this tile loader.

Returns:

A String containing the name of the layer read by this tile loader.

getLayerMetaData

public IlvObjectSDOLayerMetaData getLayerMetaData()

Returns the metadata associated to this tile loader.

Since:

JViews 5.5

connectionRestored

public void connectionRestored()
                        throws SQLException

This method is called by the IlvSDOLayer when it is read from an .ivl file, and after the connection to an Oracle Spatial database has been restored. When the connection to the database has been restored, this method collects the information that will allow the load-on-demand to work.

Overrides:

connectionRestored in class IlvSDOTileLoader

Throws:

SQLException

getTileOrigin

public IlvRect getTileOrigin()
                      throws SQLException

Returns the coordinates of the origin tile used by the load-on demand mechanism.

Specified by:

getTileOrigin in class IlvSDOTileLoader

Throws:

SQLException

setTileGroupingCount

public void setTileGroupingCount(short nb)
                          throws SQLException

Sets the number of tiles to be loaded in one single Oracle request. This tile loader can group multiple tile load requests in a single Oracle request. The advantages is that it is often faster to perform a request on a larger area than performing multiple small requests.

Parameters:

nb - The number of tiles to be grouped in a single Oracle request.

Throws:

SQLException

See Also:

getTileGroupingCount()

getTileGroupingCount

public short getTileGroupingCount()

Returns the number of tiles to be loaded in one single Oracle request.

See Also:

setTileGroupingCount(short)

setRequestParameters

public void setRequestParameters(String selectClause,
                                 String fromClause,
                                 String whereClause,
                                 String spatialOperator,
                                 String spatialOperatorParams,
                                 int fetchSize)
                          throws SQLException

Sets some parameters in order to tune the request that is used by an IlvTile. The used request is of type: "select selectClause from fromClause where whereClause and mdsys.spatialOperator (layerName.geometryColumnName, ... ), 'spatialOperatorParams') = 'TRUE'"
For instance, calling the method with the following arguments will lead to a load-on-demand only on geometries, the attributes being ignored (it supposes that the geometry column name is "GEOMETRY"): setRequestParameters("GEOMETRY", null, null, null, null);
If you don't want to use an argument of the function, pass it as null.

Parameters:

selectClause - The select clause of the request. The default value is "*".

fromClause - The from clause of the request. The default value is the name of the SDO layer.

whereClause - The where clause of the request. The default value is null.

spatialOperator - The spatial operator used in the request. The default value is "sdo_filter". For more information about spatial operators, please refer to the user's manual.

spatialOperatorParams - The parameters of the spatial operator. The default value is "querytype=window".

fetchSize - The Oracle fetch size of all the statements used in this object. If you pass 0, the parameter is ignored. The value recommended by Oracle is 10. See Statement.setFetchSize.

Throws:

SQLException

Since:

JViews 5.0

getRequestParameters

public String[] getRequestParameters()

Returns the parameters of the internal request used for load-on-demand. It returns them in the same order that the one used in the setRequestParameters method.

Returns:

The parameters of the internal request used for load-on-demand.

See Also:

setRequestParameters(java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, int)

getFetchSize

public final int getFetchSize()

Returns the fetch size parameter passed to the setRequestParameters method. The default value is 10.

Returns:

The fetch size value

Since:

JViews 5.0

See Also:

setRequestParameters(java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, int)

getResultSet

public ResultSet getResultSet(IlvTile tile)
                       throws SQLException

Returns the ResultSet containing the geometries that intersect the specified tile. This method is called by load(IlvTile tile) when a tile needs to be loaded.
You can override this method to generate a ResultSet for the specified tile using a request of your own.

Specified by:

getResultSet in class IlvSDOTileLoader

Parameters:

tile - The tile to be filled with the SDO geometries.

Throws:

SQLException

See Also:

load(ilog.views.tiling.IlvTile)

getSize

public IlvRect getSize()
                throws SQLException

Returns size of the tile loader.

Specified by:

getSize in class IlvSDOTileLoader

Throws:

SQLException

See Also:

IlvTiledLayer.getSize()

getFeatureIterator

public IlvObjectSDOFeatureIterator getFeatureIterator(ResultSet resultSet,
                                                      String geometryName,
                                                      IlvObjectSDOKeyExtractor keyExtractor,
                                                      String xDimensionName,
                                                      String yDimensionName)
                                               throws SQLException

Returns the instance of IlvObjectSDOFeatureIterator that is used by the tile loader.
You can override this method in order to use your own feature iterator.

Parameters:

resultSet - The resultSet from which geometries are read.

geometryName - The name of the column containing geometries.

keyExtractor - The extractor that can extract feature IDs from the request rows.

xDimensionName - The name of the X dimension.

yDimensionName - The name of the Y dimension.

Returns:

The instance of IlvObjectSDOFeatureIterator used internally by the tile loader.

Throws:

SQLException

load

public void load(IlvTile tile)
          throws Exception

Loads a tile from the Oracle database and adds the graphic objects to the layer of the tile. This method calls getResultSet to get the SDO geometries, transforms them into graphic objects using the renderer of the layer, and then adds the objects to the layer.

Specified by:

load in interface IlvTileLoader

Overrides:

load in class IlvSDOTileLoader

Parameters:

tile - The tile to load.

Throws:

Exception - if an error occurs while loading the tile.

See Also:

getResultSet(ilog.views.tiling.IlvTile)

write

public void write(IlvOutputStream stream)
           throws IOException

Writes this tile loader to specified stream.

Specified by:

write in interface IlvPersistentObject

Specified by:

write in interface IlvTileLoader

Overrides:

write in class IlvSDOTileLoader

Parameters:

stream - The output stream

Throws:

IOException - if a write exception occurs.

getDefaultCoordinateSystem

public IlvCoordinateSystem getDefaultCoordinateSystem()

Returns the default IlvCoordinateSystem used to render map features when they do not have a specified one. Null by default

Returns:

Returns the defaultCoordinateSystem.

Since:

JViews 7.5

setDefaultCoordinateSystem

public void setDefaultCoordinateSystem(IlvCoordinateSystem defaultCoordinateSystem)

Sets the default IlvCoordinateSystem used to render map features when they do not have a specified one. Null by default

Parameters:

defaultCoordinateSystem - The defaultCoordinateSystem to set.

Since:

JViews 7.5