GeoPkgDialect (Geotools modules 21.0 API)

Object
- SQLDialect
- - PreparedStatementSQLDialect
  - - GeoPkgDialect

```
public class GeoPkgDialect
extends PreparedStatementSQLDialect
```
The GeoPackage SQL Dialect.

Author:

Justin Deoliveira, Niels Charlier

Field Summary

Fields
Modifier and Type Field and Description

protected GeoPkgGeomWriter.Configuration geomWriterConfig
- Fields inherited from class SQLDialect
  BASE_DBMS_CAPABILITIES, dataStore, LOGGER

Fields
Modifier and Type	Field and Description
`protected GeoPkgGeomWriter.Configuration`	`geomWriterConfig`

Constructor Summary

Constructors
Constructor and Description

GeoPkgDialect(JDBCDataStore dataStore)

GeoPkgDialect(JDBCDataStore dataStore, GeoPkgGeomWriter.Configuration writerConfig)

Constructors
Constructor and Description
`GeoPkgDialect(JDBCDataStore dataStore)`
`GeoPkgDialect(JDBCDataStore dataStore, GeoPkgGeomWriter.Configuration writerConfig)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`addSupportedHints(Set<Hints.Key> hints)` Add hints to the JDBC Feature Source.
`void`	`applyLimitOffset(StringBuffer sql, int limit, int offset)` Alters the query provided so that limit and offset are natively dealt with.
`protected <T> T`	`convert(Object value, Class<T> binding)`
`CoordinateReferenceSystem`	`createCRS(int srid, Connection cx)` Turns the specified srid into a `CoordinateReferenceSystem`, or returns `null` if not possible.
`PreparedFilterToSQL`	`createPreparedFilterToSQL()`
`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, Hints hints)` 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, Hints hints)` Decodes a geometry value from the result of a query.
`void`	`encodeColumnType(String sqlTypeName, StringBuffer sql)` Encodes the type of a column in an SQL CREATE TABLE statement.
`void`	`encodeGeometryEnvelope(String tableName, String geometryColumn, StringBuffer sql)` Encodes the spatial extent function of a geometry column in a SELECT statement.
`void`	`encodePrimaryKey(String column, StringBuffer sql)` Encodes the primary key definition in a CREATE TABLE statement.
`int`	`getGeometryDimension(String schemaName, String tableName, String columnName, Connection cx)` Returns the dimension of the coordinates in the geometry.
`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 columns, Connection cx)` Determines the class mapping for a particular column of a table.
`String`	`getPkColumnValue(ResultSet rs, PrimaryKeyColumn pkey, int columnIdx)` Reads a primary key column value.
`protected PrimaryKey`	`getPrimaryKey(String typeName)`
`boolean`	`includeTable(String schemaName, String tableName, Connection cx)` Determines if the specified table should be included in those published by the datastore.
`void`	`initializeConnection(Connection cx)` Initializes a newly created database connection.
`boolean`	`isLimitOffsetSupported()` Returns true if this dialect can encode both Query.getStartIndex() and Query.getMaxFeatures() into native SQL.
`boolean`	`lookupGeneratedValuesPostInsert()` Controls whether keys are looked up post or pre insert.
`void`	`postCreateAttribute(AttributeDescriptor att, String tableName, String schemaName, Connection cx)` Callback which executes after an attribute descriptor has been built from a table column.
`void`	`postCreateTable(String schemaName, SimpleFeatureType featureType, Connection cx)` Callback to execute any additional sql statements post a create table statement.
`void`	`postDropTable(String schemaName, SimpleFeatureType featureType, Connection cx)` Callback which executes after a table has been dropped.
`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. * Subclasses should extend (not override) this method to provide additional mappings, or to override mappings provided by this implementation.
`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`	`setGeometryValue(Geometry g, int dimension, int srid, Class binding, PreparedStatement ps, int column)` Sets the geometry value into the prepared statement.
`void`	`setValue(Object value, Class binding, PreparedStatement ps, int column, Connection cx)` Sets a value in a prepared statement, for "basic types" (non-geometry).
`Filter[]`	`splitFilter(Filter filter, SimpleFeatureType schema)` Splits the filter into two parts, an encodable one, and a non encodable one.

Methods inherited from class PreparedStatementSQLDialect
convertArrayElement, convertToArray, getArrayComponentTypeName, onDelete, onInsert, onSelect, onUpdate, prepareFunctionArgument, prepareGeometryValue, prepareGeometryValue, setArrayValue

Methods inherited from class SQLDialect
createIndex, dropIndex, encodeAggregateFunction, encodeAggregateFunctionPostfix, encodeAggregateFunctionPrefix, encodeColumnAlias, encodeColumnName, encodeColumnName, encodeCreateTable, encodeGeometryColumn, encodeGeometryColumn, encodeGeometryColumn, encodeGeometryColumnGeneralized, encodeGeometryColumnGeneralized, encodeGeometryColumnSimplified, encodeGeometryColumnSimplified, encodeJoin, encodeNextSequenceValue, encodePostColumnCreateTable, encodePostCreateTable, encodePostSelect, encodeSchemaName, encodeTableAlias, encodeTableName, getDefaultVarcharSize, getDesiredTablesType, getIndexes, getLastAutoGeneratedValue, getNameEscape, getNextAutoGeneratedValue, getNextSequenceValue, getOptimizedBounds, getSequenceForColumn, handleSelectHints, handleUserDefinedType, isAggregatedSortSupported, isAutoCommitQuery, isGroupBySupported, ne, postCreateFeatureType, preDropTable, registerAggregateFunctions, registerFunctions, registerSqlTypeToClassMappings, supportsSchemaForIndex

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - geomWriterConfig
```
protected GeoPkgGeomWriter.Configuration geomWriterConfig
```
- Constructor Detail
  - GeoPkgDialect
```
public GeoPkgDialect(JDBCDataStore dataStore,
                     GeoPkgGeomWriter.Configuration writerConfig)
```
  - GeoPkgDialect
```
public GeoPkgDialect(JDBCDataStore dataStore)
```
- Method Detail
  - 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
  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 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 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 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 See Also: #decodeGeometryValue(GeometryDescriptor, ResultSet, String, GeometryFactory)}. setGeometryValue public void setGeometryValue(Geometry g, int dimension, int srid, Class binding, PreparedStatement ps, int column) throws SQLException Description copied from class: PreparedStatementSQLDialect Sets the geometry value into the prepared statement. Specified by: setGeometryValue in class PreparedStatementSQLDialect Parameters: g - The geometry srid - the geometry native srid (should be forced into the encoded geometry) binding - the geometry type ps - the prepared statement column - the column index where the geometry is to be set Throws: SQLException 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 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 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 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 getMapping public Class<?> getMapping(ResultSet columns, 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: columns - The column metadata Returns: The class mapped to the to column, or null. Throws: SQLException postCreateTable public void postCreateTable(String schemaName, SimpleFeatureType featureType, Connection cx) throws SQLException, IOException Description copied from class: SQLDialect Callback to execute any additional sql statements post a create table statement. This method should be implemented by subclasses that need to do some post processing on the database after a table has been created. Examples might include: Creating a sequence for a primary key Registering geometry column metadata Creating a spatial index A common case is creating an auto incrementing sequence for the primary key of a table. It should be noted that all tables created through the datastore use the column "fid" as the primary key. A direct connection to the database is provided (cx). This connection must not be closed, however any statements or result sets instantiated from the connection must be closed. 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 IOException 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 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 createCRS public CoordinateReferenceSystem createCRS(int srid, Connection cx) throws SQLException Description copied from class: SQLDialect Turns the specified srid into a CoordinateReferenceSystem, or returns null if not possible. The implementation might just use CRS.decode("EPSG:" + srid), but most spatial databases will have their own SRS database that can be queried as well. As a rule of thumb you should override this method if your spatial database uses codes that are not part of the EPSG standard database, of if for some reason you deem it preferable to use your database definition instead of an official EPSG one. Most overrides will try out to decode the official EPSG code first, and fall back on the custom database definition otherwise Overrides: createCRS in class SQLDialect Returns: 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 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 createPreparedFilterToSQL public PreparedFilterToSQL createPreparedFilterToSQL() Overrides: createPreparedFilterToSQL in class PreparedStatementSQLDialect setValue public void setValue(Object value, Class binding, PreparedStatement ps, int column, Connection cx) throws SQLException Description copied from class: PreparedStatementSQLDialect Sets a value in a prepared statement, for "basic types" (non-geometry). Subclasses should override this method if they need to do something custom or they wish to support non-standard types. Overrides: setValue in class PreparedStatementSQLDialect Parameters: value - the value. binding - The class of the value. ps - The prepared statement. column - The column the value maps to. cx - The database connection. Throws: SQLException encodeColumnType public void encodeColumnType(String sqlTypeName, StringBuffer sql) Description copied from class: SQLDialect Encodes the type of a column in an SQL CREATE TABLE statement. The default implementation simply outputs the sqlTypeName argument as is. Subclasses may override this method. Such cases might include: A type definition requires some parameter, ex: size of a varchar The provided attribute (att) contains some additional restrictions that can be encoded in the type, ex: field length Overrides: encodeColumnType in class SQLDialect postCreateAttribute public void postCreateAttribute(AttributeDescriptor att, String tableName, String schemaName, Connection cx) throws SQLException Description copied from class: SQLDialect Callback which executes after an attribute descriptor has been built from a table column. The result set columnMetadata should not be modified in any way (including scrolling) , it should only be read from. This base implementation does nothing, subclasses should override as need be. Overrides: postCreateAttribute in class SQLDialect Parameters: att - The built attribute descriptor. tableName - The name of the table containing the column schemaName - The name of the database scheam containing the table containing the column cx - The database connection. Throws: SQLException 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 Returns: getPrimaryKey protected PrimaryKey getPrimaryKey(String typeName) throws IOException Overrides: getPrimaryKey in class SQLDialect Throws: IOException convert protected <T> T convert(Object value, Class<T> binding) Overrides: convert in class PreparedStatementSQLDialect getPkColumnValue public String getPkColumnValue(ResultSet rs, PrimaryKeyColumn pkey, int columnIdx) throws SQLException Description copied from class: SQLDialect Reads a primary key column value. By default uses ResultSet.getString(int), subclasses can use a more efficient way should they wish to Overrides: getPkColumnValue in class SQLDialect 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

Class GeoPkgDialect

Field Summary

Fields inherited from class SQLDialect

Constructor Summary

Method Summary

Methods inherited from class PreparedStatementSQLDialect

Methods inherited from class SQLDialect

Methods inherited from class Object

Field Detail

geomWriterConfig

Constructor Detail

GeoPkgDialect

GeoPkgDialect

Method Detail

initializeConnection

includeTable

encodePrimaryKey

encodeGeometryEnvelope

decodeGeometryEnvelope

decodeGeometryValue

decodeGeometryValue

setGeometryValue

getGeometryTypeName

registerSqlTypeNameToClassMappings

registerClassToSqlMappings

registerSqlTypeToSqlTypeNameOverrides

getMapping

postCreateTable

postDropTable

getGeometrySRID

getGeometryDimension

createCRS

lookupGeneratedValuesPostInsert

getLastAutoGeneratedValue

isLimitOffsetSupported

applyLimitOffset

createPreparedFilterToSQL

setValue

encodeColumnType

postCreateAttribute

splitFilter

getPrimaryKey

convert

getPkColumnValue

addSupportedHints