Package adql.db

Class STCS


  • public final class STCS
    extends java.lang.Object

    This class helps dealing with the subset of STC-S expressions described by the section "6 Use of STC-S in TAP (informative)" of the TAP Recommendation 1.0 (27th March 2010). This subset is limited to the most common coordinate systems and regions.

    Note: No instance of this class can be created. Its usage is only limited to its static functions and classes.

    Coordinate system

    The function parseCoordSys(String) is able to parse a string containing only the STC-S expression of a coordinate system (or an empty string or null which would be interpreted as the default coordinate system - UNKNOWNFRAME UNKNOWNREFPOS SPHERICAL2). When successful, this parsing returns an object representation of the coordinate system: STCS.CoordSys.

    To serialize into STC-S a coordinate system, you have to create a STCS.CoordSys instance with the desired values and to call the function STCS.CoordSys.toSTCS(). The static function toSTCS(CoordSys) is just calling the STCS.CoordSys.toSTCS() on the given coordinate system.

    Geometrical region

    As for the coordinate system, there is a static function to parse the STC-S representation of a geometrical region: parseRegion(String). Here again, when the parsing is successful an object representation is returned: STCS.Region.

    This class lets also serializing into STC-S a region. The procedure is the same as with a coordinate system: create a STCS.Region and then call STCS.Region.toString().

    The class STCS.Region lets also dealing with the ADQLFunction implementing a region. It is then possible to create a STCS.Region object from a such ADQLFunction and to get the corresponding STC-S representation. The static function toSTCS(GeometryFunction) is a helpful function which do these both actions in once.

    Note: The conversion from ADQLFunction to STCS.Region or STC-S is possible only if the ADQLFunction contains constants as parameter. Thus, a such function using a column, a concatenation, a math operation or using another function can not be converted into STC-S using this class.

    Since:
    1.3
    Version:
    1.4 (04/2017)
    Author:
    Grégory Mantelet (ARI)
    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  STCS.CoordSys
      Object representation of an STC coordinate system.
      static class  STCS.Flavor
      List of all possible flavors in an STC expression.
      static class  STCS.Frame
      List of all possible frames in an STC expression.
      static class  STCS.RefPos
      List of all possible reference positions in an STC expression.
      static class  STCS.Region
      Object representation of an STC region.
      static class  STCS.RegionType
      List all possible region types allowed in an STC-S expression.
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static java.lang.String buildCoordSysRegExp​(java.lang.String[] allowedCoordSys)
      Build a big regular expression gathering all of the given coordinate system syntaxes.
      static STCS.CoordSys parseCoordSys​(java.lang.String stcs)
      Parse the given STC-S representation of a coordinate system.
      static STCS.Region parseRegion​(java.lang.String stcsRegion)
      Parse the given STC-S expression representing a geometrical region.
      static java.lang.String toSTCS​(STCS.CoordSys coordSys)
      Convert an object representation of a coordinate system into an STC-S expression.
      static java.lang.String toSTCS​(STCS.Region region)
      Convert into STC-S the given object representation of a geometrical region.
      static java.lang.String toSTCS​(GeometryFunction region)
      Convert into STC-S the given ADQL representation of a geometrical function.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Method Detail

      • parseCoordSys

        public static STCS.CoordSys parseCoordSys​(java.lang.String stcs)
                                           throws ParseException
        Parse the given STC-S representation of a coordinate system.
        Parameters:
        stcs - STC-S expression of a coordinate system. Note: a NULL or empty string will be interpreted as a default coordinate system.
        Returns:
        The object representation of the specified coordinate system.
        Throws:
        ParseException - If the given expression has a wrong STC-S syntax.
      • toSTCS

        public static java.lang.String toSTCS​(STCS.CoordSys coordSys)

        Convert an object representation of a coordinate system into an STC-S expression.

        Note: A NULL object will be interpreted as the default coordinate system and so an empty string will be returned. Otherwise, this function is equivalent to STCS.CoordSys.toSTCS() (in which default values for each coordinate system part is not displayed).

        Parameters:
        coordSys - The object representation of the coordinate system to convert into STC-S.
        Returns:
        The corresponding STC-S expression.
        See Also:
        STCS.CoordSys.toSTCS(), STCS.CoordSys.toFullSTCS()
      • buildCoordSysRegExp

        public static java.lang.String buildCoordSysRegExp​(java.lang.String[] allowedCoordSys)
                                                    throws ParseException

        Build a big regular expression gathering all of the given coordinate system syntaxes.

        Each item of the given list must respect a strict syntax. Each part of the coordinate system may be a single value, a list of values or a '*' (meaning all values are allowed). A list of values must have the following syntax: ({value1}|{value2}|...). An empty string is NOT here accepted.

        Example: (ICRS|FK4|FK5) * SPHERICAL2 is OK, but (ICRS|FK4|FK5) * is not valid because the flavor value is not defined.

        Since the default value of each part of a coordinate system should always be possible, this function ensure these default values are always possible in the returned regular expression. Thus, if some values except the default one are specified, the default value is automatically appended.

        Note: If the given array is NULL, all coordinate systems are allowed. But if the given array is empty, none except an empty string or the default value will be allowed.

        Parameters:
        allowedCoordSys - List of all coordinate systems that are allowed.
        Returns:
        The corresponding regular expression.
        Throws:
        ParseException - If the syntax of one of the given allowed coordinate system is wrong.
      • parseRegion

        public static STCS.Region parseRegion​(java.lang.String stcsRegion)
                                       throws ParseException
        Parse the given STC-S expression representing a geometrical region.
        Parameters:
        stcsRegion - STC-S expression of a region. Note: MUST be different from NULL.
        Returns:
        The object representation of the specified geometrical region.
        Throws:
        ParseException - If the given expression is NULL, empty string or if the STC-S syntax is wrong.
      • toSTCS

        public static java.lang.String toSTCS​(STCS.Region region)
        Convert into STC-S the given object representation of a geometrical region.
        Parameters:
        region - Region to convert into STC-S.
        Returns:
        The corresponding STC-S expression.