Package org.geotools.data.postgis

Class PostGISDialect

Object
SQLDialect
BasicSQLDialect
PostGISDialect
public class PostGISDialect extends BasicSQLDialect

  • Field Details

  • Constructor Details

    • PostGISDialect

      public PostGISDialect(JDBCDataStore dataStore)

  • Method Details

    • isAggregatedSortSupported

      public boolean isAggregatedSortSupported(String function)
      Description copied from class: SQLDialect
      Returns true if this dialect supports sorting together with the given aggregation function.
      Overrides:
      isAggregatedSortSupported in class SQLDialect

    • isLooseBBOXEnabled

      public boolean isLooseBBOXEnabled()

    • setLooseBBOXEnabled

      public void setLooseBBOXEnabled(boolean looseBBOXEnabled)

    • isEncodeBBOXFilterAsEnvelope

      public boolean isEncodeBBOXFilterAsEnvelope()

    • setEncodeBBOXFilterAsEnvelope

      public void setEncodeBBOXFilterAsEnvelope(boolean encodeBBOXFilterAsEnvelope)

    • isEstimatedExtentsEnabled

      public boolean isEstimatedExtentsEnabled()

    • setEstimatedExtentsEnabled

      public void setEstimatedExtentsEnabled(boolean estimatedExtentsEnabled)

    • isFunctionEncodingEnabled

      public boolean isFunctionEncodingEnabled()

    • setFunctionEncodingEnabled

      public void setFunctionEncodingEnabled(boolean functionEncodingEnabled)
      See Also:

    • isSimplifyEnabled

      public boolean isSimplifyEnabled()

    • isEscapeBackslash

      public boolean isEscapeBackslash()

    • canSimplifyPoints

      public boolean canSimplifyPoints()
      Description copied from class: SQLDialect
      Returns if points can be returned in simplified form (e.g reduced precision, like TWKB encoding)
      Overrides:
      canSimplifyPoints in class SQLDialect

    • setSimplifyEnabled

      public void setSimplifyEnabled(boolean simplifyEnabled)
      Enables/disables usage of ST_Simplify geometry wrapping when the Query contains a geometry simplification hint

    • isTopologyPreserved

      public boolean isTopologyPreserved()

    • setTopologyPreserved

      public void setTopologyPreserved(boolean topologyPreserved)
      Enables/disables usage of ST_SimplifyPreserveTopology, instead of ST_Simplify when simplification has to be applied.
      Parameters:
      topologyPreserved -

    • initializeConnection

      public void initializeConnection(Connection cx) throws SQLException
      Description copied from class: SQLDialect
      Initializes a newly created database connection.

      Subclasses should override this method if there is some additional action that needs to be taken when a new connection to the database is created. The default implementation does nothing.

      Overrides:
      initializeConnection in class SQLDialect
      Parameters:
      cx - The new database connection.
      Throws:
      SQLException

    • 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, Hints hints) 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, Hints hints) 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

    • encodeGeometryColumn

      public void encodeGeometryColumn(GeometryDescriptor gatt, String prefix, int srid, Hints hints, 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, String, StringBuffer) function.

      Example: 

         
   sql.append( "asText(" );
   column( gatt.getLocalName(), sql );
   sql.append( ")" );
      Overrides:
      encodeGeometryColumn in class SQLDialect

    • encodeGeometryColumnSimplified

      public void encodeGeometryColumnSimplified(GeometryDescriptor gatt, String prefix, int srid, StringBuffer sql, Double distance)
      Overrides:
      encodeGeometryColumnSimplified in class SQLDialect

    • isStraightSegmentsGeometry

      protected boolean isStraightSegmentsGeometry(GeometryDescriptor gatt)

    • 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 #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.
      cx - The database connection.
      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 are used to determine the mapping. Subclasses should implement as needed, this default implementation returns <code>null</code>. </p> <p> The <tt>columnMetaData</tt> argument is provided from {@link DatabaseMetaData#getColumns(String, String, String, String)}. </p>

      Overrides:
      getMapping in class SQLDialect
      Parameters:
      columnMetaData - The column metadata
      cx - The connection used to retrieve the 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 the 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

    • createCRS

      public CoordinateReferenceSystem createCRS(int srid, Connection cx) throws SQLException
      Using PostGIS table spatial_ref_sys to determine authority name and code of srid
      Overrides:
      createCRS in class SQLDialect
      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

    • getGeometryDimension

      public int getGeometryDimension(String schemaName, String tableName, String columnName, Connection cx) throws SQLException
      Description copied from class: SQLDialect
      Returns the dimension of the coordinates in the geometry. Defaults to 2, subclasses can override it.

      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 dimension cannot be determined, this method should return 2

      Overrides:
      getGeometryDimension 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

    • getDimensionFromFirstGeo

      protected Integer getDimensionFromFirstGeo(String schemaName, String tableName, String columnName, Connection cx) throws SQLException
      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

    • encodeNextSequenceValue

      public String encodeNextSequenceValue(String schemaName, String sequenceName)
      Description copied from class: SQLDialect
      Encodes how to get the next sequence value from the DB.

      Implementations should handle the case where schemaName is null.

      Overrides:
      encodeNextSequenceValue in class SQLDialect

    • 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:

      Subclasses returning true should implement:

      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

    • postDropTable

      public void postDropTable(String schemaName, SimpleFeatureType featureType, Connection cx) throws SQLException
      Description copied from class: SQLDialect
      Callback which executes after a table has been dropped.

      This base implementation does nothing, subclasses should override as need be.

      Overrides:
      postDropTable in class SQLDialect
      Parameters:
      schemaName - The database schema containing the table.
      featureType - The featureType/table being dropped.
      cx - The database connection.
      Throws:
      SQLException

    • encodeGeometryValue

      public void encodeGeometryValue(Geometry value, int dimension, 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.

      Attention should be paid to emtpy geometries (g.isEmtpy() == true) as they cannot be encoded in WKB and several databases fail to handle them property. Common treatment is to equate them to NULL

      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

    • 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
      Throws:
      SQLException

    • getPostgreSQLVersion

      public Version getPostgreSQLVersion(Connection conn) throws SQLException
      Returns the PostgreSQL version
      Throws:
      SQLException

    • addSupportedHints

      protected void addSupportedHints(Set<Hints.Key> hints)
      Description copied from class: SQLDialect
      Add hints to the JDBC Feature Source. A subclass can override

      possible hints (but not limited to)

      Hints.GEOMETRY_GENERALIZATION Hints.GEOMETRY_SIMPLIFICATION

      Overrides:
      addSupportedHints in class SQLDialect

    • getEstimatedExtentFunction

      protected String getEstimatedExtentFunction()
      Returns "ST_EstimatedExtent" if PostGIS version is >= 2.1.0, otherwise "ST_Estimated_Extent"
      Returns:
      EstimatedExtent function name

    • splitFilter

      public Filter[] splitFilter(Filter filter, SimpleFeatureType schema)
      Description copied from class: SQLDialect
      Splits the filter into two parts, an encodable one, and a non encodable one. The default implementation uses the filter capabilities to split the filter, subclasses can implement their own logic if need be.
      Overrides:
      splitFilter in class SQLDialect

    • getDesiredTablesType

      public String[] getDesiredTablesType()
      Overrides:
      getDesiredTablesType in class SQLDialect
      Returns:
      Table types filtered from jdbc DatabaseMetaData

    • canGroupOnGeometry

      public boolean canGroupOnGeometry()
      Description copied from class: SQLDialect
      Returns true if this database can "group by" on a Geometry column. Defaults to false, specific implementations with this capability should override
      Overrides:
      canGroupOnGeometry in class SQLDialect