org.geotools.data.postgis
Class PostGISDialect

Object
  SQLDialect
      BasicSQLDialect
          PostGISDialect

public class PostGISDialect
extends BasicSQLDialect

Field Summary

Fields inherited from class SQLDialect

BASE_DBMS_CAPABILITIES, dataStore, LOGGER

Constructor Summary

PostGISDialect(JDBCDataStore dataStore)

Method Summary

void	applyLimitOffset(StringBuffer sql, int limit, int offset) Alters the query provided so that limit and offset are natively dealt with.
FilterToSQL	createFilterToSQL() Creates the filter encoder to be used by the datastore when encoding query predicates.
Envelope	decodeGeometryEnvelope(ResultSet rs, int column, Connection cx) Decodes the result of a spatial extent function in a SELECT statement.
Geometry	decodeGeometryValue(GeometryDescriptor descriptor, ResultSet rs, int column, GeometryFactory factory, Connection cx) Decodes a geometry value from the result of a query specifying the column as an index.
Geometry	decodeGeometryValue(GeometryDescriptor descriptor, ResultSet rs, String column, GeometryFactory factory, Connection cx) Decodes a geometry value from the result of a query.
void	encodeGeometryColumn(GeometryDescriptor gatt, int srid, StringBuffer sql) Encodes the name of a geometry column in a SELECT statement.
void	encodeGeometryEnvelope(String tableName, String geometryColumn, StringBuffer sql) Encodes the spatial extent function of a geometry column in a SELECT statement.
void	encodeGeometryValue(Geometry value, int srid, StringBuffer sql) Encodes a geometry value in an sql statement.
void	encodePrimaryKey(String column, StringBuffer sql) Encodes the primary key definition in a CREATE TABLE statement.
void	encodeValue(Object value, Class type, StringBuffer sql) Encodes a value in an sql statement.
int	getDefaultVarcharSize() Determines the default length that a varchar field should be when creating datastore tables from feature types.
Integer	getGeometrySRID(String schemaName, String tableName, String columnName, Connection cx) Returns the spatial reference system identifier (srid) for a particular geometry column.
String	getGeometryTypeName(Integer type) Returns the name of a geometric type based on its integer constant.
Object	getLastAutoGeneratedValue(String schemaName, String tableName, String columnName, Connection cx) Obtains the last value of an auto generated column.
Class<?>	getMapping(ResultSet columnMetaData, Connection cx) Determines the class mapping for a particular column of a table.
Object	getNextSequenceValue(String schemaName, String sequenceName, Connection cx) Obtains the next value of a sequence, incrementing the sequence to the next state in the process.
List<ReferencedEnvelope>	getOptimizedBounds(String schema, SimpleFeatureType featureType, Connection cx) Returns the bounds of all geometry columns in the layer using any approach that proves to be faster than the plain bounds aggregation (e.g., better than the "plain select extent(geom) from table" on PostGIS), or null if none exists or the fast method has not been enabled (e.g., if the fast method is just an estimate of the bounds you probably want the user to enable it manually)
String	getSequenceForColumn(String schemaName, String tableName, String columnName, Connection cx) Determines the name of the sequence (if any) which is used to increment generate values for a table column.
Version	getVersion(Connection conn) Returns the PostGIS version
void	handleUserDefinedType(ResultSet columnMetaData, ColumnMetadata metadata, Connection cx) Handles the mapping for a user defined type.
boolean	includeTable(String schemaName, String tableName, Connection cx) Determines if the specified table should be included in those published by the datastore.
boolean	isEstimatedExtentsEnabled()
boolean	isLimitOffsetSupported() Returns true if this dialect can encode both Query.getStartIndex() and Query.getMaxFeatures() into native SQL.
boolean	isLooseBBOXEnabled()
boolean	lookupGeneratedValuesPostInsert() Controls whether keys are looked up post or pre insert.
void	postCreateTable(String schemaName, SimpleFeatureType featureType, Connection cx) Creates GEOMETRY_COLUMN registrations and spatial indexes for all geometry columns
void	registerClassToSqlMappings(Map<Class<?>,Integer> mappings) Registers the java type to sql type mappings that the datastore uses when reading and writing objects to and from the database
void	registerSqlTypeNameToClassMappings(Map<String,Class<?>> mappings) Registers the sql type name to java type mappings that the dialect uses when reading and writing objects to and from the database.
void	registerSqlTypeToSqlTypeNameOverrides(Map<Integer,String> overrides) Registers any overrides that should occur when mapping an integer sql type value to an underlying sql type name.
void	setEstimatedExtentsEnabled(boolean estimatedExtentsEnabled)
void	setLooseBBOXEnabled(boolean looseBBOXEnabled)

Methods inherited from class BasicSQLDialect

onDelete, onInsert, onSelect, onUpdate

Methods inherited from class SQLDialect

addSupportedHints, createCRS, encodeColumnAlias, encodeColumnName, encodeColumnType, encodeGeometryColumnGeneralized, encodeGeometryColumnSimplified, encodePostColumnCreateTable, encodePostCreateTable, encodePostSelect, encodeSchemaName, encodeTableAlias, encodeTableName, getNameEscape, getNextAutoGeneratedValue, initializeConnection, isAutoCommitQuery, ne, postCreateAttribute, postCreateFeatureType, registerAggregateFunctions, registerSqlTypeToClassMappings

Methods inherited from class Object

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

Constructor Detail

PostGISDialect

public PostGISDialect(JDBCDataStore dataStore)

Method Detail

isLooseBBOXEnabled

public boolean isLooseBBOXEnabled()

setLooseBBOXEnabled

public void setLooseBBOXEnabled(boolean looseBBOXEnabled)

isEstimatedExtentsEnabled

public boolean isEstimatedExtentsEnabled()

setEstimatedExtentsEnabled

public void setEstimatedExtentsEnabled(boolean estimatedExtentsEnabled)

includeTable

public boolean includeTable(String schemaName,
                            String tableName,
                            Connection cx)
                     throws SQLException

Description copied from class: SQLDialect

Determines if the specified table should be included in those published by the datastore.

This method returns true if the table should be published as a feature type, otherwise it returns false. Subclasses should override this method, this default implementation returns true.

A database connection is provided to the dialect but it should not be closed. However any statements objects or result sets that are instantiated from it must be closed.

Overrides:

includeTable in class SQLDialect

Parameters:

schemaName - The schema of the table, might be null..

tableName - The name of the table.

cx - Database connection.

Throws:

SQLException

decodeGeometryValue

public Geometry decodeGeometryValue(GeometryDescriptor descriptor,
                                    ResultSet rs,
                                    String column,
                                    GeometryFactory factory,
                                    Connection cx)
                             throws IOException,
                                    SQLException

Description copied from class: SQLDialect

Decodes a geometry value from the result of a query.

This method is given direct access to a result set. The column parameter is the index into the result set which contains the geometric value.

An implementation should deserialize the value provided by the result set into Geometry object. For example, consider an implementation which deserializes from well known text:

   String wkt = rs.getString( column );
   if ( wkt == null ) {
     return null;
   }
   return new WKTReader(factory).read( wkt );
   

Note that implementations must handle null values.

The factory parameter should be used to instantiate any geometry objects.

Specified by:

decodeGeometryValue in class SQLDialect

Throws:

IOException

SQLException

decodeGeometryValue

public Geometry decodeGeometryValue(GeometryDescriptor descriptor,
                                    ResultSet rs,
                                    int column,
                                    GeometryFactory factory,
                                    Connection cx)
                             throws IOException,
                                    SQLException

Description copied from class: SQLDialect

Decodes a geometry value from the result of a query specifying the column as an index.

See #decodeGeometryValue(GeometryDescriptor, ResultSet, String, GeometryFactory) for a more in depth description.

Overrides:

decodeGeometryValue in class SQLDialect

Throws:

IOException

SQLException

See Also:

#decodeGeometryValue(GeometryDescriptor, ResultSet, String, GeometryFactory)}.

encodeGeometryColumn

public void encodeGeometryColumn(GeometryDescriptor gatt,
                                 int srid,
                                 StringBuffer sql)

Description copied from class: SQLDialect

Encodes the name of a geometry column in a SELECT statement.

This method should wrap the column name in any functions that are used to retrieve its value. For instance, often it is necessary to use the function asText, or asWKB when fetching a geometry.

This method must also be sure to properly encode the name of the column with the SQLDialect.encodeColumnName(String, StringBuffer) function.

Example:

   
   sql.append( "asText(" );
   column( gatt.getLocalName(), sql );
   sql.append( ")" );
   
 

This default implementation simply uses the column name without any wrapping function, subclasses must override.

Overrides:

encodeGeometryColumn in class SQLDialect

encodeGeometryEnvelope

public void encodeGeometryEnvelope(String tableName,
                                   String geometryColumn,
                                   StringBuffer sql)

Description copied from class: SQLDialect

Encodes the spatial extent function of a geometry column in a SELECT statement.

This method must also be sure to properly encode the name of the column with the SQLDialect.encodeColumnName(String, StringBuffer) function.

Specified by:

encodeGeometryEnvelope in class SQLDialect

getOptimizedBounds

public List<ReferencedEnvelope> getOptimizedBounds(String schema,
                                                   SimpleFeatureType featureType,
                                                   Connection cx)
                                            throws SQLException,
                                                   IOException

Description copied from class: SQLDialect

Returns the bounds of all geometry columns in the layer using any approach that proves to be faster than the plain bounds aggregation (e.g., better than the "plain select extent(geom) from table" on PostGIS), or null if none exists or the fast method has not been enabled (e.g., if the fast method is just an estimate of the bounds you probably want the user to enable it manually)

Overrides:

getOptimizedBounds in class SQLDialect

Parameters:

schema - The database schema, if any, or null

featureType - The feature type containing the geometry columns whose bounds need to computed. Mind, it may be retyped and thus contain less geometry columns than the table

Returns:

a list of referenced envelopes (some of which may be null or empty)

Throws:

SQLException

IOException

decodeGeometryEnvelope

public Envelope decodeGeometryEnvelope(ResultSet rs,
                                       int column,
                                       Connection cx)
                                throws SQLException,
                                       IOException

Description copied from class: SQLDialect

Decodes the result of a spatial extent function in a SELECT statement.

This method is given direct access to a result set. The column parameter is the index into the result set which contains the spatial extent value. The query for this value is build with the SQLDialect.encodeGeometryEnvelope(String, String, StringBuffer) method.

This method must not read any other objects from the result set other then the one referenced by column.

Specified by:

decodeGeometryEnvelope in class SQLDialect

Parameters:

rs - A result set

column - Index into the result set which points at the spatial extent value.

Throws:

SQLException

IOException

getMapping

public Class<?> getMapping(ResultSet columnMetaData,
                           Connection cx)
                    throws SQLException

Description copied from class: SQLDialect

Determines the class mapping for a particular column of a table.

Implementing this method is optional. It is used to allow database to perform custom type mappings based on various column metadata. It is called before the mappings registered in SQLDialect.registerSqlTypeToClassMappings(Map) and #registerSqlTypeNameToClassMappings(Map) are used to determine the mapping. Subclasses should implement as needed, this default implementation returns null.

The columnMetaData argument is provided from {@link DatabaseMetaData#getColumns(String, String, String, String)}.

Overrides:

getMapping in class SQLDialect

Parameters:

columnMetaData - The column metadata

Returns:

The class mapped to the to column, or null.

Throws:

SQLException

handleUserDefinedType

public void handleUserDefinedType(ResultSet columnMetaData,
                                  ColumnMetadata metadata,
                                  Connection cx)
                           throws SQLException

Description copied from class: SQLDialect

Handles the mapping for a user defined type.

This method is called after SQLDialect.getMapping(ResultSet, Connection) but before the rest of the type mapping heuristics are applied.

Implementing this method is optional. It is used to allow for handling user defined types or "DOMAINS". Dialects that implement this method should set the appropriate information on the metadata object to allow the column to be mapped via teh regular type mapping heuristics.

Overrides:

handleUserDefinedType in class SQLDialect

Parameters:

columnMetaData - The column metdata.

metadata - The column metadata object that collections mapping information.

cx - The database connection, not to be closed.

Throws:

SQLException

getGeometrySRID

public Integer getGeometrySRID(String schemaName,
                               String tableName,
                               String columnName,
                               Connection cx)
                        throws SQLException

Description copied from class: SQLDialect

Returns the spatial reference system identifier (srid) for a particular geometry column.

This method is given a direct connection to the database. The connection must not be closed. However any statements or result sets instantiated from the connection must be closed.

In the event that the srid cannot be determined, this method should return null.

Overrides:

getGeometrySRID in class SQLDialect

Parameters:

schemaName - The database schema, could be null.

tableName - The table, never null.

columnName - The column name, never null

cx - The database connection.

Throws:

SQLException

getSequenceForColumn

public String getSequenceForColumn(String schemaName,
                                   String tableName,
                                   String columnName,
                                   Connection cx)
                            throws SQLException

Description copied from class: SQLDialect

Determines the name of the sequence (if any) which is used to increment generate values for a table column.

This method should return null if no such sequence exists.

This method is given a direct connection to the database, but this connection should never be closed. However any statements or result sets instantiated from the connection must be closed.

Overrides:

getSequenceForColumn in class SQLDialect

Parameters:

schemaName - The schema name, this might be null.

tableName - The table name.

columnName - The column name.

cx - The database connection.

Throws:

SQLException

getNextSequenceValue

public Object getNextSequenceValue(String schemaName,
                                   String sequenceName,
                                   Connection cx)
                            throws SQLException

Description copied from class: SQLDialect

Obtains the next value of a sequence, incrementing the sequence to the next state in the process.

Implementations should determine the next value of a column for which values are automatically generated by the database.

This method is given a direct connection to the database, but this connection should never be closed. However any statements or result sets instantiated from the connection must be closed.

Implementations should handle the case where schemaName is null.

Overrides:

getNextSequenceValue in class SQLDialect

Parameters:

schemaName - The schema name, this might be null.

sequenceName - The name of the sequence.

cx - The database connection.

Returns:

The next value of the sequence, or null.

Throws:

SQLException

lookupGeneratedValuesPostInsert

public boolean lookupGeneratedValuesPostInsert()

Description copied from class: SQLDialect

Controls whether keys are looked up post or pre insert.

When a row is inserted into a table, and a key is automatically generated it can be looked up before the insert occurs, or after the insert has been made. Returning false will cause the lookup to occur before the insert via SQLDialect.getNextAutoGeneratedValue(String, String, String, Connection). Returning true will cause the lookup to occur after the insert via SQLDialect.getLastAutoGeneratedValue(String, String, String, Connection).

Subclasses returning false should implement:

• SQLDialect.getNextAutoGeneratedValue(String, String, String, Connection)

Subclasses returning true should implement:

• SQLDialect.getLastAutoGeneratedValue(String, String, String, Connection)

Overrides:

lookupGeneratedValuesPostInsert in class SQLDialect

getLastAutoGeneratedValue

public Object getLastAutoGeneratedValue(String schemaName,
                                        String tableName,
                                        String columnName,
                                        Connection cx)
                                 throws SQLException

Description copied from class: SQLDialect

Obtains the last value of an auto generated column.

This method is only called when SQLDialect.lookupGeneratedValuesPostInsert() returns true. Implementations should determine the previous value of a column for which was automatically generated by the database.

This method is given a direct connection to the database, but this connection should never be closed. However any statements or result sets instantiated from the connection must be closed.

Implementations should handle the case where schemaName is null.

Overrides:

getLastAutoGeneratedValue in class SQLDialect

Parameters:

schemaName - The schema name, this might be null.

tableName - The name of the table.

columnName - The column.

cx - The database connection.

Returns:

The previous value of the column, or null.

Throws:

SQLException

registerClassToSqlMappings

public void registerClassToSqlMappings(Map<Class<?>,Integer> mappings)

Description copied from class: SQLDialect

Registers the java type to sql type mappings that the datastore uses when reading and writing objects to and from the database. *

Subclasses should extend (not override) this method to provide additional mappings, or to override mappings provided by this implementation. This implementation provides the following mappings:

Overrides:

registerClassToSqlMappings in class SQLDialect

registerSqlTypeNameToClassMappings

public void registerSqlTypeNameToClassMappings(Map<String,Class<?>> mappings)

Description copied from class: SQLDialect

Registers the sql type name to java type mappings that the dialect uses when reading and writing objects to and from the database.

Subclasses should extend (not override) this method to provide additional mappings, or to override mappings provided by this implementation. This implementation provides the following mappings:

Overrides:

registerSqlTypeNameToClassMappings in class SQLDialect

registerSqlTypeToSqlTypeNameOverrides

public void registerSqlTypeToSqlTypeNameOverrides(Map<Integer,String> overrides)

Description copied from class: SQLDialect

Registers any overrides that should occur when mapping an integer sql type value to an underlying sql type name.

The default implementation of this method does nothing. Subclasses should override in cases where:

• database type metadata does not provide enough information to properly map
• to support custom types (those not in Types)

Overrides:

registerSqlTypeToSqlTypeNameOverrides in class SQLDialect

getGeometryTypeName

public String getGeometryTypeName(Integer type)

Description copied from class: SQLDialect

Returns the name of a geometric type based on its integer constant.

The constant, type, is registered in SQLDialect.registerSqlTypeNameToClassMappings(Map).

This default implementation returns null, subclasses should override.

Overrides:

getGeometryTypeName in class SQLDialect

encodePrimaryKey

public void encodePrimaryKey(String column,
                             StringBuffer sql)

Description copied from class: SQLDialect

Encodes the primary key definition in a CREATE TABLE statement.

Subclasses should override this method if need be, the default implementation does the following:

   
   encodeColumnName( column, sql );
   sql.append( " int PRIMARY KEY" );
   
 

Overrides:

encodePrimaryKey in class SQLDialect

postCreateTable

public void postCreateTable(String schemaName,
                            SimpleFeatureType featureType,
                            Connection cx)
                     throws SQLException

Creates GEOMETRY_COLUMN registrations and spatial indexes for all geometry columns

Overrides:

postCreateTable in class SQLDialect

Parameters:

schemaName - The name of the schema, may be null.

featureType - The feature type that has just been created on the database.

cx - Database connection.

Throws:

SQLException

encodeGeometryValue

public void encodeGeometryValue(Geometry value,
                                int srid,
                                StringBuffer sql)
                         throws IOException

Description copied from class: BasicSQLDialect

Encodes a geometry value in an sql statement.

An implementations should serialize value into some exchange format which will then be transported to the underlying database. For example, consider an implementation which converts a geometry into its well known text representation:

   
   sql.append( "GeomFromText('" );
   sql.append( new WKTWriter().write( value ) );
   sql.append( ")" );
   
  

The srid parameter is the spatial reference system identifier of the geometry, or 0 if not known.

Specified by:

encodeGeometryValue in class BasicSQLDialect

Throws:

IOException

createFilterToSQL

public FilterToSQL createFilterToSQL()

Description copied from class: BasicSQLDialect

Creates the filter encoder to be used by the datastore when encoding query predicates.

Sublcasses can override this method to return a subclass of FilterToSQL if need be.

Overrides:

createFilterToSQL in class BasicSQLDialect

isLimitOffsetSupported

public boolean isLimitOffsetSupported()

Description copied from class: SQLDialect

Returns true if this dialect can encode both Query.getStartIndex() and Query.getMaxFeatures() into native SQL.

Overrides:

isLimitOffsetSupported in class SQLDialect

Returns:

applyLimitOffset

public void applyLimitOffset(StringBuffer sql,
                             int limit,
                             int offset)

Description copied from class: SQLDialect

Alters the query provided so that limit and offset are natively dealt with. This might mean simply appending some extra directive to the query, or wrapping it into a bigger one.

Overrides:

applyLimitOffset in class SQLDialect

encodeValue

public void encodeValue(Object value,
                        Class type,
                        StringBuffer sql)

Description copied from class: BasicSQLDialect

Encodes a value in an sql statement.

Subclasses may wish to override or extend this method to handle specific types. This default implementation does the following:

1. The value is encoded via its Object.toString() representation.
2. If type is a character type (extends CharSequence), it is wrapped in single quotes (').

Overrides:

encodeValue in class BasicSQLDialect

getDefaultVarcharSize

public int getDefaultVarcharSize()

Description copied from class: SQLDialect

Determines the default length that a varchar field should be when creating datastore tables from feature types.

Some dialects allow no length to be specified for varchar fields (PostGIS for example) however others require a maximum length to be set.

Subclasses can override this method and either return -1 to specify that no length is required, or otherwise return an appropriate default length for varchars of that dialect.

Overrides:

getDefaultVarcharSize in class SQLDialect

getVersion

public Version getVersion(Connection conn)
                   throws SQLException

Returns the PostGIS version

Returns:

Throws:

SQLException