Class IckleQueryOperators

  • public class IckleQueryOperators
    extends Object
    This class provides knowledge on how to build Ickle query where clauses for specified ModelCriteriaBuilder.Operator.

    For example,

    for operator ModelCriteriaBuilder.Operator.EQ we concatenate left operand and right operand with equal sign: fieldName = :parameterName

    however, for operator ModelCriteriaBuilder.Operator.EXISTS we add following:

    fieldName IS NOT NULL AND fieldName IS NOT EMPTY". For right side operands we use named parameters to avoid injection attacks. Mapping between named parameter and corresponding value is then saved into Map<String, Object> that is passed to each IckleQueryOperators.ExpressionCombinator.

    • Constructor Detail

      • IckleQueryOperators

        public IckleQueryOperators()
    • Method Detail

      • findAvailableNamedParam

        public static String findAvailableNamedParam​(Set<String> existingNames,
                                                     String namePrefix)
        Maps namePrefix to next available parameter name. For example, if namePrefix == "id" and existingNames set already contains id0 and id1 it returns id2. Any character that is not an alphanumeric will be stripped, so that it works for prefixes like "" as well. This method is used for computing available names for name query parameters. Instead of creating generic named parameters that would be hard to debug and read by humans, it creates readable named parameters from the prefix.
        existingNames - set of parameter names that are already used in this Ickle query
        namePrefix - name of the parameter
        next available parameter name
      • combineExpressions

        public static String combineExpressions​(ModelCriteriaBuilder.Operator op,
                                                String modelFieldName,
                                                Object[] values,
                                                Map<String,​Object> parameters)
        Provides a string containing where clause for given operator, field name and values
        op - operator
        modelFieldName - field name
        values - values
        parameters - mapping between named parameters and their values
        where clause