com.luciad.format.sqlite.spatialite

LuciadLightspeedClass TLcdSpatiaLiteModelEncoder

java.lang.Object

com.luciad.format.sqlite.spatialite.TLcdSpatiaLiteModelEncoder

All Implemented Interfaces:

ILcdModelEncoder, Serializable

@LcdService(service=ILcdModelEncoder.class,
            priority=20000)
public class TLcdSpatiaLiteModelEncoder
extends Object
implements ILcdModelEncoder

This ILcdModelEncoder encodes models into SQLite SpatiaLite databases.

A spatial database is accessed based on a set of properties. The properties can be passed in a Properties object, or using a properties file with extension "spl".

The common properties needed to establish a connection and to specify tables, columns, rows, etc. are the same as those for the TLcdSpatiaLiteModelDecoder. In addition, the following properties are required:

• SRID the spatial reference ID for the spatial data.
• geometryType (default = "GEOMETRY"): asi defined in the Simple Features Specification for SQL (OpenGIS)
• featureDataTypes.0, ...: the SQL data types of the feature columns. Each featureNames.i must have a corresponding featureDataTypes.i.
• dropBeforeCreatingTable (optional, default = false): if set to true, the encoder will attempt to drop the spatial table before re-creating it.

Example properties file:

 # The basic database connection properties.
 driver    = org.sqlite.JDBC
 url       = jdbc:sqlite:database.sqlite
 

 # The data of interest.
 table         = STATES
 spatialColumn = GEOM
 

 # The feature columns to be decoded.
 featureNames.0 = ID
 featureNames.1 = STATE
 

 # The index of the feature that can be used as primary key.
 primaryFeatureIndex = 0
 

 # Optional additional constraints to retrieve a subset of the table.
 #selectionTables =
 #selectionFilter = STATE = 'New York'
 

 # Optional maximum cache size (expressed as number of objects, default is 100).
 maxCacheSize = 60
 

 # Optionally close the database connection after each query.
 #alwaysCloseConnection = false
 

 # Additional properties required for creating a new SQLite SpatiaLite table.
 SRID = 4326 # WGS 84 lon lat
 

 # Optional geometry type of the geometry column.
 #geometryType = MULTIPOLYGON
 

 # The regular SQL data types of the feature columns.
 featureDataTypes.0 = NUMERIC(11,3)
 featureDataTypes.1 = CHAR(20)
 

The encoder supports ILcdShape objects. They are converted to SQLite SpatiaLite objects as follows:

FROM ILcdShape	TO WKB GEOMETRY
ILcd2DEditablePoint	POINT
ILcd2DEditablePolypoint	MULTIPOINT
ILcd2DEditablePolyline	POLYLINE
ILcd2DEditablePolygon	POLYGON
ILcdComplexPolygon	POLYGON
ILcdShapeList containing multiple ILcd2DEditablePoint instances	MULTIPOINT
ILcdShapeList containing multiple ILcd2DEditablePolyline instances	MULTIPOLYLINE
ILcdShapeList containing multiple ILcd2DEditablePolygon instances	MULTIPOLYGON
ILcdShapeList containing multiple ILcdComplexPolygon instances	MULTIPOLYGON
ILcdShapeList containing one of the above (recursive) instances	GEOMETRYCOLLECTION

If the shape list contains only a single element, the element will be considered on its own, without the enclosing shape list.

Features are retrieved by means of the ILcdFeatured interface, which the objects must implement.

Limitations

• Feature names in the properties must refer to column names; they cannot be more complex SQL expressions.
• Selection filters and selection tables are ignored when encoding; they are only used for decoding.
• The encoder does not support the ILcdDataObject interface, only the ILcdFeatured interface.

Since:

11.0

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
TLcdSpatiaLiteModelEncoder() Creates a new SpatiaLite SQLite model encoder.

Method Summary

Modifier and Type	Method and Description
boolean	canExport(ILcdModel aModel, String aDestinationName) Returns whether the given model can be saved into the database described by the given properties file.
boolean	canSave(ILcdModel aModel) Returns whether the given model can be saved back into the database.
void	export(ILcdModel aModel, Properties aProperties) Exports the given model in a new table, based on the given properties.
void	export(ILcdModel aModel, String aDestinationName) Exports the given model in a new table, based on the properties in the given file.
int	getAutoCommitCount() Returns the number of inserted elements after which an export operation is committed.
String	getDisplayName() Returns a short, displayable name for the format this ILcdModelEncoder encodes to.
void	save(ILcdModel aModel) Saves the given model in its original location, by committing all changes.
void	setAutoCommitCount(int aAutoCommitCount) Sets the number of inserted elements after which an export operation should be committed, periodically.

Methods inherited from class java.lang.Object

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

Constructor Detail

TLcdSpatiaLiteModelEncoder

public TLcdSpatiaLiteModelEncoder()

Creates a new SpatiaLite SQLite model encoder.

Method Detail

setAutoCommitCount

public void setAutoCommitCount(int aAutoCommitCount)

Sets the number of inserted elements after which an export operation should be committed, periodically. The default is 0, meaning that the export operation is only committed when all elements have been inserted. A different value can be useful to avoid overflow of database transaction logs.

getAutoCommitCount

public int getAutoCommitCount()

Returns the number of inserted elements after which an export operation is committed.

getDisplayName

public String getDisplayName()

Description copied from interface: ILcdModelEncoder

Returns a short, displayable name for the format this ILcdModelEncoder encodes to.

Specified by:

getDisplayName in interface ILcdModelEncoder

Returns:

the displayable name of this ILcdModelEncoder.

canExport

public boolean canExport(ILcdModel aModel,
                         String aDestinationName)

Returns whether the given model can be saved into the database described by the given properties file.

Specified by:

canExport in interface ILcdModelEncoder

Parameters:

aModel - the model to be verified.

aDestinationName - the location where the model should be exported to.

Returns:

true if this encoder can export the specified model to the specified location, false otherwise.

See Also:

ILcdModelEncoder.export(com.luciad.model.ILcdModel, java.lang.String)

export

public void export(ILcdModel aModel,
                   String aDestinationName)
            throws IOException,
                   IllegalArgumentException

Exports the given model in a new table, based on the properties in the given file.

Specified by:

export in interface ILcdModelEncoder

Parameters:

aModel - the model to be exported.

aDestinationName - the properties file describing the database table to be created.

Throws:

IOException - for any database access errors. This includes the case where the table already exists.

IllegalArgumentException - if the model cannot be saved by this encoder (!canExport(aModel, aDestinationName)).

export

public void export(ILcdModel aModel,
                   Properties aProperties)
            throws IOException,
                   IllegalArgumentException

Exports the given model in a new table, based on the given properties.

Parameters:

aModel - the model to be exported.

aProperties - the properties describing the database table to be created.

Throws:

IOException - for any database access errors. This includes the case where the table already exists.

IllegalArgumentException

canSave

public boolean canSave(ILcdModel aModel)

Returns whether the given model can be saved back into the database.

Specified by:

canSave in interface ILcdModelEncoder

Parameters:

aModel - the model to be verified.

Returns:

true if this encoder can save the model in the location where it originally came from, false otherwise.

See Also:

ILcdModelEncoder.save(com.luciad.model.ILcdModel)

save

public void save(ILcdModel aModel)
          throws IOException,
                 IllegalArgumentException

Saves the given model in its original location, by committing all changes.

Specified by:

save in interface ILcdModelEncoder

Parameters:

aModel - the database model to be committed.

Throws:

IOException - for any database access errors.

IllegalArgumentException - if the model cannot be saved by this encoder (!canSave(aModel)).