Class IsNullImpl

All Implemented Interfaces:
Filter, MultiValuedFilter, PropertyIsNull, FilterType

public class IsNullImpl extends CompareFilterImpl implements PropertyIsNull
  • Constructor Details

    • IsNullImpl

      public IsNullImpl(Expression expression)
  • Method Details

    • evaluate

      public boolean evaluate(Object feature)
      Description copied from interface: Filter
      Give an object, this method determines if the test(s) represented by this filter object are passed.

      This ability is used to allow Queries against both Features and and non spatial data (such as Record) and to express constraints on permissable data values.

      Specified by:
      evaluate in interface Filter
      Returns:
      true if the test(s) are passed for the provided object
    • accept

      public Object accept(FilterVisitor visitor, Object extraData)
      Description copied from class: CompareFilterImpl
      Used by FilterVisitors to perform some action on this filter instance. Typicaly used by Filter decoders, but may also be used by any thing which needs infomration from filter structure. Implementations should always call: visitor.visit(this); It is importatant that this is not left to a parent class unless the parents API is identical.
      Specified by:
      accept in interface Filter
      Specified by:
      accept in class CompareFilterImpl
      Parameters:
      visitor - The visitor which requires access to this filter, the method must call visitor.visit(this);
    • getExpression

      public Expression getExpression()
      Description copied from interface: PropertyIsNull
      Returns the expression whose value will be checked for null.
      Specified by:
      getExpression in interface PropertyIsNull
    • setExpression

      public void setExpression(Expression expression)