Package org.geotools.referencing

Class CRS

    • Method Detail

      • isCompatible

        public static boolean isCompatible​(CoordinateReferenceSystem sourceCrs,
                                   CoordinateReferenceSystem targetCrs,
                                   boolean allowDifferentDimension)
        Determines if one coordinate reference system is compatible with another, i.e. can be transformed to the other
        Parameters:
        sourceCrs - the source CRS
        targetCrs - the target CRS
        allowDifferentDimension - if true, returns false if CRS's have different dimensions regardless of the ability to transform.
        Returns:
        compatibility as boolean

      • getCoordinateOperationFactory

        public static CoordinateOperationFactory getCoordinateOperationFactory​(boolean lenient)
        Returns the coordinate operation factory used by findMathTransform convenience methods.
        Parameters:
        lenient - true if the coordinate operations should be created even when there is no information available for a datum shift.
        Since:
        2.4

      • getVersion

        public static Version getVersion​(String authority)
                          throws FactoryRegistryException
        Returns the version number of the specified authority database, or null if not available.
        Parameters:
        authority - The authority name (typically "EPSG").
        Returns:
        The version number of the authority database, or null if unknown.
        Throws:
        FactoryRegistryException - if no CRSAuthorityFactory implementation was found for the specified authority.
        Since:
        2.4

      • getSupportedCodes

        public static Set<String> getSupportedCodes​(String authority)
        Get the list of the codes that are supported by the given authority. For example getSupportedCodes("EPSG") may returns "EPSG:2000", "EPSG:2001", "EPSG:2002", etc. It may also returns "2000", "2001", "2002", etc. without the "EPSG:" prefix. Whatever the authority name is prefixed or not is factory implementation dependent.

        If there is more than one factory for the given authority, then this method merges the code set of all of them. If a factory fails to provide a set of supported code, then this particular factory is ignored. Please be aware of the following potential issues:

        • If there is more than one EPSG databases (for example an Access and a PostgreSQL ones), then this method will connect to all of them even if their content are identical.
        • If two factories format their codes differently (e.g. "4326" and "EPSG:4326"), then the returned set will contain a lot of synonymous codes.
        • For any code c in the returned set, there is no warranty that decode(c) will use the same authority factory than the one that formatted c.
        • This method doesn't report connection problems since it doesn't throw any exception. FactoryExceptions are logged as warnings and otherwise ignored.

        If a more determinist behavior is wanted, consider the code below instead. The following code exploit only one factory, the "preferred" one.

        CRSAuthorityFactory factory = FactoryFinder.getCRSAuthorityFactory(authority, null);
        Set<String> codes = factory.getAuthorityCodes(CoordinateReferenceSystem.class);
        String code = ...choose a code here...
        CoordinateReferenceSystem crs = factory.createCoordinateReferenceSystem(code);
        Parameters:
        authority - The authority name (for example "EPSG").
        Returns:
        The set of supported codes. May be empty, but never null.

      • getSupportedAuthorities

        public static Set<String> getSupportedAuthorities​(boolean returnAliases)
        Returns the set of the authority identifiers supported by registered authority factories. This method search only for CRS authority factories.
        Parameters:
        returnAliases - If true, the set will contain all identifiers for each authority. If false, only the first one
        Returns:
        The set of supported authorities. May be empty, but never null.
        Since:
        2.3.1

      • decode

        public static CoordinateReferenceSystem decode​(String code,
                                               boolean longitudeFirst)
                                        throws NoSuchAuthorityCodeException,
                                               FactoryException
        Return a Coordinate Reference System for the specified code, maybe forcing the axis order to (longitude, latitude). The code argument value is parsed as in " decode(code)". The longitudeFirst argument value controls the hints to be given to the factory finder as in the following pseudo-code: 

         if (longitudeFirst) {
     hints.put(Hints.FORCE_LONGITUDE_FIRST_AXIS_ORDER, Boolean.TRUE);
 } else {
     // Do not set the FORCE_LONGITUDE_FIRST_AXIS_ORDER hint to FALSE.
     // Left it unset, which means "use system default".
 }
        The following table compare this method longitudeFirst argument with the hint meaning:

        This method argument Hint value Meaning
        true TRUE All coordinate reference systems are forced to (longitude, latitude) axis order.
        false null Coordinate reference systems may or may not be forced to (longitude, latitude) axis order. The behavior depends on user setting, for example the value of the "org.geotools.referencing.forceXY" system property.
        FALSE Forcing (longitude, latitude) axis order is not allowed, no matter the value of the "org.geotools.referencing.forceXY" system property.
        Parameters:
        code - The Coordinate Reference System authority code.
        longitudeFirst - true if axis order should be forced to (longitude, latitude). Note that false means "use default", not "latitude first".
        Returns:
        The Coordinate Reference System for the provided code.
        Throws:
        NoSuchAuthorityCodeException - If the code could not be understood.
        FactoryException - if the CRS creation failed for an other reason.
        Since:
        2.3
        See Also:
        getSupportedCodes(java.lang.String), Hints.FORCE_LONGITUDE_FIRST_AXIS_ORDER

      • getHorizontalCRS

        public static SingleCRS getHorizontalCRS​(CoordinateReferenceSystem crs)
        Returns the first horizontal coordinate reference system found in the given CRS, or null if there is none. A horizontal CRS is usually a two-dimensional geographic or projected CRS.
        Parameters:
        crs - The coordinate reference system, or null.
        Returns:
        The horizontal CRS, or null if none.
        Since:
        2.4

      • getProjectedCRS

        public static ProjectedCRS getProjectedCRS​(CoordinateReferenceSystem crs)
        Returns the first projected coordinate reference system found in a the given CRS, or null if there is none.
        Parameters:
        crs - The coordinate reference system, or null.
        Returns:
        The projected CRS, or null if none.
        Since:
        2.4

      • getVerticalCRS

        public static VerticalCRS getVerticalCRS​(CoordinateReferenceSystem crs)
        Returns the first vertical coordinate reference system found in a the given CRS, or null if there is none.
        Parameters:
        crs - The coordinate reference system, or null.
        Returns:
        The vertical CRS, or null if none.
        Since:
        2.4

      • getTemporalCRS

        public static TemporalCRS getTemporalCRS​(CoordinateReferenceSystem crs)
        Returns the first temporal coordinate reference system found in the given CRS, or null if there is none.
        Parameters:
        crs - The coordinate reference system, or null.
        Returns:
        The temporal CRS, or null if none.
        Since:
        2.4

      • getEllipsoid

        public static Ellipsoid getEllipsoid​(CoordinateReferenceSystem crs)
        Returns the first ellipsoid found in a coordinate reference system, or null if there is none.
        Parameters:
        crs - The coordinate reference system, or null.
        Returns:
        The ellipsoid, or null if none.
        Since:
        2.4

      • equalsIgnoreMetadata

        public static boolean equalsIgnoreMetadata​(Object object1,
                                           Object object2)
        Compares the specified objects for equality. If both objects are Geotools implementations of class AbstractIdentifiedObject, then this method will ignore the metadata during the comparison.
        Parameters:
        object1 - The first object to compare (may be null).
        object2 - The second object to compare (may be null).
        Returns:
        true if both objects are equals.
        Since:
        2.2

      • toSRS

        public static String toSRS​(CoordinateReferenceSystem crs)
        Returns the Spatial Reference System identifier, or null if none. OGC Web Services have the concept of a Spatial Reference System identifier used to communicate CRS information between systems.

        Spatial Reference System (ie SRS) values:

        • EPSG:4326 - this is the usual format understood to mean forceXY order prior to WMS 1.3.0. Note that the axis order is not necessarly (longitude, latitude), but this is the common behavior we observe in practice.
        • AUTO:43200 -
        • CRS:84 - similar to DefaultGeographicCRS.WGS84 (formally defined by CRSAuthorityFactory)
        • ogc:uri:..... - understood to match the EPSG database axis order.
        • Well Known Text (WKT)
        Parameters:
        crs - The coordinate reference system, or null.
        Returns:
        SRS represented as a string for communication between systems, or null.
        Since:
        2.5

      • toSRS

        public static String toSRS​(CoordinateReferenceSystem crs,
                           boolean codeOnly)
        Returns the Spatial Reference System identifier, or null if none.

        Some older web services are unable to deal with the full ogc:uri syntax, set simple to true for force a very simple representation that is just based on the code portion.

        Parameters:
        codeOnly - Set to true to force generation of a simple srsName using only the code portion
        Returns:
        srsName

      • lookupIdentifier

        public static String lookupIdentifier​(Citation authority,
                                      CoordinateReferenceSystem crs,
                                      boolean fullScan)
                               throws FactoryException
        Looks up an identifier of the specified authority for the given coordinate reference system). This method is similar to lookupIdentifier(object, fullScan) except that the search is performed only among the factories of the given authority.

        If the CRS does not have an identifier which corresponds to the EPSG authority, then:

        • if fullScan is true, then this method scans the factories in search for an object equals, ignoring metadata, to the given object. If one is found, its identifier is returned.
        • Otherwise (if fullScan is false or if no identifier was found in the previous step), this method returns null.
        Parameters:
        authority - The authority for the code to search.
        crs - The coordinate reference system instance, or null.
        Returns:
        The CRS identifier, or null if none was found.
        Throws:
        FactoryException - if an error occured while searching for the identifier.
        Since:
        2.5

      • lookupEpsgCode

        public static Integer lookupEpsgCode​(CoordinateReferenceSystem crs,
                                     boolean fullScan)
                              throws FactoryException
        Looks up an EPSG code for the given coordinate reference system). This is a convenience method for lookupIdentifier(Citations.EPSG, crs, fullScan) except that code is parsed as an integer.
        Parameters:
        crs - The coordinate reference system instance, or null.
        Returns:
        The CRS identifier, or null if none was found.
        Throws:
        FactoryException - if an error occured while searching for the identifier.
        Since:
        2.5

      • findMathTransform

        public static MathTransform findMathTransform​(CoordinateReferenceSystem sourceCRS,
                                              CoordinateReferenceSystem targetCRS,
                                              String transformCode)
                                       throws FactoryException
        Grab a transform between two Coordinate Reference Systems with the required transformation being used.

        Sample use:

        MathTransform transform = CRS.findMathTransform( CRS.decode("EPSG:21036"), CRS.decode("EPSG:32736"), "EPSG:1285" );
        Parameters:
        sourceCRS - The source CRS.
        targetCRS - The target CRS.
        transformCode - - the transform operation desired.
        Returns:
        The math transform from sourceCRS to targetCRS using the transformCode if it is found, otherwise the first transform found will be returned.
        Throws:
        FactoryException - If no math transform can be created for the specified source and target CRS.

      • findMathTransform

        public static MathTransform findMathTransform​(CoordinateReferenceSystem sourceCRS,
                                              CoordinateReferenceSystem targetCRS,
                                              boolean lenient)
                                       throws FactoryException
        Grab a transform between two Coordinate Reference Systems. This method is similar to findMathTransform(sourceCRS, targetCRS), except that it can optionally tolerate lenient datum shift. If the lenient argument is true, then this method will not throw a "Bursa-Wolf parameters required" exception during datum shifts if the Bursa-Wolf paramaters are not specified. Instead it will assume a no datum shift.
        Parameters:
        sourceCRS - The source CRS.
        targetCRS - The target CRS.
        lenient - true if the math transform should be created even when there is no information available for a datum shift. The default value is false.
        Returns:
        The math transform from sourceCRS to targetCRS.
        Throws:
        FactoryException - If no math transform can be created for the specified source and target CRS.
        See Also:
        Hints.LENIENT_DATUM_SHIFT

      • transform

        public static GeneralBounds transform​(Bounds envelope,
                                      CoordinateReferenceSystem targetCRS)
                               throws TransformException
        Transforms the given envelope to the specified CRS. If the given envelope is null, or the envelope CRS is null, or the given target CRS is null, or the transform is identity, then the envelope is returned unchanged. Otherwise a new transformed envelope is returned.

        Don't use this method if there is many envelopes to transform. This method is provided as a convenience when there is only one envelope to transform between CRS that can't be known in advance. If there is many of them or if the CRS are restricted to known values, get the coordinate operation or math transform once for ever and invoke one of the methods below instead (unless if performance is not a concern).

        Parameters:
        envelope - The envelope to transform (may be null).
        targetCRS - The target CRS (may be null).
        Returns:
        A new transformed envelope, or directly envelope if no transformation was required.
        Throws:
        TransformException - If a transformation was required and failed.
        Since:
        2.5

      • transform

        public static GeneralBounds transform​(MathTransform transform,
                                      Bounds envelope)
                               throws TransformException
        Transforms an envelope using the given math transform. The transformation is only approximative. Note that the returned envelope may not have the same number of dimensions than the original envelope.

        Note that this method can not handle the case where the envelope contains the North or South pole, or when it cross the ±180° longitude, because math transforms do not carry suffisient informations. For a more robust envelope transformation, use transform(CoordinateOperation, Bounds) instead.

        Parameters:
        transform - The transform to use.
        envelope - Envelope to transform, or null. This envelope will not be modified.
        Returns:
        The transformed envelope, or null if envelope was null.
        Throws:
        TransformException - if a transform failed.
        Since:
        2.4
        See Also:
        transform(CoordinateOperation, Bounds)

      • transform

        public static GeneralBounds transform​(CoordinateOperation operation,
                                      Bounds envelope)
                               throws TransformException
        Transforms an envelope using the given coordinate operation. The transformation is only approximative. It may be bigger than the smallest possible bounding box, but should not be smaller. Note that the returned envelope may not have the same number of dimensions than the original envelope.

        This method can handle the case where the envelope contains the North or South pole, or when it cross the ±180° longitude.

        Parameters:
        operation - The operation to use. Source and target dimension must be 2.
        envelope - Envelope to transform, or null. This envelope will not be modified.
        Returns:
        The transformed envelope, or null if envelope was null.
        Throws:
        TransformException - if a transform failed.
        Since:
        2.4
        See Also:
        transform(MathTransform, Bounds)

      • cleanupThreadLocals

        public static void cleanupThreadLocals()
        Cleans up the thread local set in this thread. They can prevent web applications from proper shutdown

      • getAxisOrder

        public static CRS.AxisOrder getAxisOrder​(CoordinateReferenceSystem crs,
                                         boolean useBaseGeoCRS)
        Determines the axis ordering of a specified crs object.

        The useBaseGeoCRS parameter is used to control behaviour for projected crs. When set to true the comparison will use the coordinate system for the underlying geographic crs object for the comparison. When set to false the comparison will use the coordinate system from projected crs itself.

        Parameters:
        crs - The coordinate reference system.
        useBaseGeoCRS - Controls whether the base geo crs is used for projected crs.
        Returns:
        One of CRS.AxisOrder.EAST_NORTH, {@link AxisOrder@NORTH_EAST}, or CRS.AxisOrder.INAPPLICABLE

      • main

        public static void main​(String... args)
        Prints to the standard output stream some information about coordinate reference systems specified by their authority codes. This method can be invoked from the command line in order to test the authority factory content for some specific CRS.

        By default, this method prints all enumerated objects as Well Known Text. However this method can prints different kind of information if an option such as -factories, -codes or -bursawolfs is provided.

        Usage: java org.geotools.referencing.CRS [options] [codes]
        Options:

        -authority=name
        Uses the specified authority factory, for example "EPSG". The authority name can be any of the authorities listed by the -factories option. If this option is not specified, then the default is all factories.

        -bursawolfs codes
        Lists the Bursa-Wolf parameters for the specified CRS ou datum objects. For some transformations, there is more than one set of Bursa-Wolf parameters available. The standard Well Known Text format prints only what look like the "main" one. This option display all Bursa-Wolf parameters in a table for a given object.

        -codes
        Lists all available authority codes. Use the -authority option if the list should be restricted to a single authority.

        -colors
        Enable syntax coloring on ANSI X3.64 compatible (aka ECMA-48 and ISO/IEC 6429) terminal. This option tries to highlight most of the elements relevant to the equalsIgnoreMetadata method, with the addition of Bursa-Wolf parameters.

        -encoding=charset
        Sets the console encoding for this application output. This value has no impact on data, but may improve the output quality. This is not needed on Linux terminal using UTF-8 encoding (tip: the terminus font gives good results).

        -dependencies
        Lists authority factory dependencies as a tree.

        -factories
        Lists all availables CRS authority factories.

        -forcexy
        Force "longitude first" axis order.

        -help
        Prints the list of options.

        -locale=name
        Formats texts in the specified locale.

        -operations sourceCRS targetCRS
        Prints all available coordinate operations between a pair of CRS. This option prints only the operations explicitly defined in a database like EPSG. There is sometime many such operations, and sometime none (in which case this option prints nothing - it doesn't try to find an operation by itself).

        -transform sourceCRS targetCRS
        Prints the preferred math transform between a pair of CRS. At the difference of the "-operations" option, this option pick up only one operation (usually the most accurate one), inferring it if none were explicitly specified in the database.

        Examples (assuming that "CRS" is a shortcut for "java org.geotools.referencing.CRS"):

        CRS EPSG:4181 EPSG:4326 CRS:84 AUTO:42001,30,0
        Prints the "Luxembourg 1930" CRS, the "WGS 84" CRS (from EPSG database), the ""WGS84" CRS (from the Web Map Service specification) and a UTM projection in WKT format.

        CRS -authority=EPSG 4181 4326
        Prints the "Luxembourg 1930" and "WGS 84" CRS, looking only in the EPSG database (so there is no need to prefix the codes with "EPSG").

        CRS -colors EPSG:7411
        Prints the "NTF (Paris) / Lambert zone II + NGF Lallemand" CRS with syntax coloring enabled.

        CRS -bursawolfs EPSG:4230
        Prints three set of Bursa-Wolf parameters for a CRS based on "European Datum 1950".

        CRS -authority=EPSG -operations 4230 4326
        Prints all operations declared in the EPSG database from "ED50" to "WGS 84" geographic CRS. Note that for this particular pair of CRS, there is close to 40 operations declared in the EPSG database. This method prints only the ones that Geotools can handle.

        CRS -transform EPSG:4230 EPSG:4326
        Prints the math transform that Geotools would use by default for coordinate transformation from "ED50" to "WGS 84".

        Parameters:
        args - Options and list of object codes to display.
        Since:
        2.4