Package org.geotools.filter

Class FunctionExpressionImpl

Object
ExpressionAbstract
DefaultExpression
FunctionExpressionImpl
All Implemented Interfaces:
Expression, Function, FunctionExpression, Factory
Direct Known Subclasses:
AndFunction, AreaFunction, ArrayFunction, AsMultiGeometryFunctionExpression, AtFunction, AttributeCountFunction, BandsFunction, ClassifyFunction, Collection_AverageFunction, Collection_BoundsFunction, Collection_CountFunction, Collection_MaxFunction, Collection_MedianFunction, Collection_MinFunction, Collection_SumFunction, Collection_UniqueFunction, CollectionIdFunction, CollectionLinkFunction, DateDifferenceFunction, EnvFunction, FallbackFunction, FilterFunction_abs, FilterFunction_abs_2, FilterFunction_abs_3, FilterFunction_abs_4, FilterFunction_acos, FilterFunction_area, FilterFunction_asin, FilterFunction_atan, FilterFunction_atan2, FilterFunction_between, FilterFunction_boundary, FilterFunction_boundaryDimension, FilterFunction_buffer, FilterFunction_bufferWithSegments, FilterFunction_ceil, FilterFunction_centroid, FilterFunction_contains, FilterFunction_Convert, FilterFunction_convexHull, FilterFunction_cos, FilterFunction_crosses, FilterFunction_dateFormat, FilterFunction_dateParse, FilterFunction_difference, FilterFunction_dimension, FilterFunction_disjoint, FilterFunction_disjoint3D, FilterFunction_distance, FilterFunction_distance3D, FilterFunction_double2bool, FilterFunction_endAngle, FilterFunction_endPoint, FilterFunction_envelope, FilterFunction_equalsExact, FilterFunction_equalsExactTolerance, FilterFunction_equalTo, FilterFunction_exp, FilterFunction_exteriorRing, FilterFunction_floor, FilterFunction_geometryType, FilterFunction_geomFromWKT, FilterFunction_geomLength, FilterFunction_getGeometryN, FilterFunction_getX, FilterFunction_getY, FilterFunction_getZ, FilterFunction_greaterEqualThan, FilterFunction_greaterThan, FilterFunction_IEEEremainder, FilterFunction_if_then_else, FilterFunction_in10, FilterFunction_in2, FilterFunction_in3, FilterFunction_in4, FilterFunction_in5, FilterFunction_in6, FilterFunction_in7, FilterFunction_in8, FilterFunction_in9, FilterFunction_int2bbool, FilterFunction_int2ddouble, FilterFunction_interiorPoint, FilterFunction_interiorRingN, FilterFunction_intersection, FilterFunction_intersects, FilterFunction_intersects3D, FilterFunction_isClosed, FilterFunction_isCoverage, FilterFunction_isEmpty, FilterFunction_isLike, FilterFunction_isNull, FilterFunction_isometric, FilterFunction_isRing, FilterFunction_isSimple, FilterFunction_isValid, FilterFunction_isWithinDistance, FilterFunction_isWithinDistance3D, FilterFunction_lessEqualThan, FilterFunction_lessThan, FilterFunction_list, FilterFunction_listMultiply, FilterFunction_log, FilterFunction_max, FilterFunction_max_2, FilterFunction_max_3, FilterFunction_max_4, FilterFunction_min, FilterFunction_min_2, FilterFunction_min_3, FilterFunction_min_4, FilterFunction_minimumCircle, FilterFunction_minimumDiameter, FilterFunction_minimumRectangle, FilterFunction_not, FilterFunction_notEqualTo, FilterFunction_numberFormat, FilterFunction_numberFormat2, FilterFunction_numGeometries, FilterFunction_numInteriorRing, FilterFunction_numPoints, FilterFunction_octagonalEnvelope, FilterFunction_offset, FilterFunction_overlaps, FilterFunction_parseBoolean, FilterFunction_parseDouble, FilterFunction_parseInt, FilterFunction_parseLong, FilterFunction_pgNearest, FilterFunction_pointN, FilterFunction_pow, FilterFunction_property, FilterFunction_random, FilterFunction_relate, FilterFunction_relatePattern, FilterFunction_rint, FilterFunction_round, FilterFunction_round_2, FilterFunction_roundDouble, FilterFunction_sdonn, FilterFunction_setCRS, FilterFunction_sin, FilterFunction_sqrt, FilterFunction_startAngle, FilterFunction_startPoint, FilterFunction_strAbbreviate, FilterFunction_strCapitalize, FilterFunction_strConcat, FilterFunction_strDefaultIfBlank, FilterFunction_strEndsWith, FilterFunction_strEqualsIgnoreCase, FilterFunction_strIndexOf, FilterFunction_strLastIndexOf, FilterFunction_strLength, FilterFunction_strMatches, FilterFunction_strPosition, FilterFunction_strReplace, FilterFunction_strStartsWith, FilterFunction_strStripAccents, FilterFunction_strSubstring, FilterFunction_strSubstringStart, FilterFunction_strToLowerCase, FilterFunction_strToUpperCase, FilterFunction_strTrim, FilterFunction_strTrim2, FilterFunction_symDifference, FilterFunction_tan, FilterFunction_toDegrees, FilterFunction_toRadians, FilterFunction_touches, FilterFunction_toWKT, FilterFunction_union, FilterFunction_vertices, FilterFunction_within, GeometryFunction, GetFunction, HasFunction, IDFunction, IDFunctionExpression, InArrayFunction, InFunction, IntegerDivisionFunction, JsonArrayContainsFunction, JsonPointerFunction, JsonSelectAllFunction, JsonSelectFunction, LapplyFunction, LengthFunction, LinFunction, ListSizeFunction, LitemFunction, LiterateFunction, MapBoxAnchorFunction, MapBoxLengthFunction, MapGetFunction, NestedCollectionLinkFunction, NorthFix, NowFunction, OrFunction, PaletteFunction, PiFunction, PointOnLineFunction, PropertyExistsFunction, RescaleToPixelsFunction, SizeFunction, ToRgb, URLEncodeFunction, ZoomLevelFunction
public abstract class FunctionExpressionImpl extends DefaultExpression implements FunctionExpression
Abstract class for a function expression implementation

By default this implementation returns the provided fallback value. To implement a function please override the evaluate(Object) method.

Author:
James Macgill, PSU

  • Field Details

    • name

      protected String name
      function name *

    • params

      protected List<Expression> params
      function params *

    • fallback

      protected Literal fallback

    • functionName

      protected FunctionName functionName
      FunctionName provided by subclass; or lazely created

  • Constructor Details

    • FunctionExpressionImpl

      protected FunctionExpressionImpl(FunctionName functionName)
      Preferred constructor to ensure name and functionName match.

      Recommended use: 

       import static org.geotools.filter.capability.FunctionNameImpl.*;
 public class AreaFunction extends FunctionExpressionImpl {

   public static FunctionName NAME = new FunctionNameImpl("Area",
        parameter("area",Double.class),
        parameter("geometry",Geometry.class));

 public AreaFunction() {
     super(NAME);
 }
      Parameters:
      functionName - FunctionName describing subclass

    • FunctionExpressionImpl

      protected FunctionExpressionImpl(String name)

    • FunctionExpressionImpl

      protected FunctionExpressionImpl(Name name)

    • FunctionExpressionImpl

      protected FunctionExpressionImpl(String name, Literal fallback)
      Creates a new instance of FunctionExpression

    • FunctionExpressionImpl

      protected FunctionExpressionImpl(Name name, Literal fallback)
      Creates a new instance of FunctionExpression

  • Method Details

    • getName

      public String getName()
      Gets the name of this function.
      Specified by:
      getName in interface Function
      Returns:
      the name of the function.

    • getFunctionName

      public FunctionName getFunctionName()
      Description copied from interface: Function
      Access to the FunctionName description as used in a FilterCapabilities document.
      Specified by:
      getFunctionName in interface Function
      Returns:
      FunctionName description, if available.

    • getFallbackValue

      public Literal getFallbackValue()
      Description copied from interface: Function
      The value of the fallbackValue attribute is used as a default value, if the SE implementation does not support the function. If the implementation supports the function, then the result value is determined by executing the function.
      Specified by:
      getFallbackValue in interface Function
      Returns:
      Optional literal to use if an implementation for this function is not available.

    • setFallbackValue

      public void setFallbackValue(Literal fallback)
      Description copied from interface: FunctionExpression
      Fallback value to use in the event the function is unavailable in the requested environment.

      The fallback value is not provided as one of the arguments, as it is an advanced option used in style layer descriptor documents to facilitate interoperability. It allows a user to specify an SQL function, and provide a value to use when the documented is used with a WFS that does not support the provided function.

      Specified by:
      setFallbackValue in interface FunctionExpression

    • getParameters

      public List<Expression> getParameters()
      Returns the function parameters.
      Specified by:
      getParameters in interface Function

    • setParameters

      public void setParameters(List<Expression> params)
      Sets the function parameters.
      Specified by:
      setParameters in interface FunctionExpression

    • accept

      public Object accept(ExpressionVisitor visitor, Object extraData)
      Description copied from interface: Expression
      Accepts a visitor. Subclasses must implement with a method whose content is the following: 
      return visitor.visit(this, extraData);
      Specified by:
      accept in interface Expression
      See Also:

    • getImplementationHints

      public Map<RenderingHints.Key,?> getImplementationHints()
      Returns the implementation hints. The default implementation returns an empty map.
      Specified by:
      getImplementationHints in interface Factory
      Returns:
      The map of hints, or an {@linkplain java.util.Collections.emptyMap() empty map} if none.

    • functionName

      protected static FunctionName functionName(String name, String ret, String... args)
      Convenience method for creating a function name.
      See Also:

    • toString

      public String toString()
      Creates a String representation of this Function with the function name and the arguments. The String created should be good for most subclasses
      Overrides:
      toString in class Object

    • getExpression

      protected Expression getExpression(int index)
      Utility method for subclasses to ask for an argument at a given index

    • evaluate

      public Object evaluate(Object object)
      Description copied from class: ExpressionAbstract
      Subclass should override, default implementation returns null.
      Specified by:
      evaluate in interface Expression
      Overrides:
      evaluate in class ExpressionAbstract
      Returns:
      default implementation returns null

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object