com.im.df.api.dml
Class DFTermsFactory

java.lang.Object
  com.im.df.api.dml.DFTermsFactory

public final class DFTermsFactory
extends Object

The factory class for creating DFTerms. This class has only limited methods which creates only expression of some specific patterns which are currently supported by DIF execution. So it's not possible to create DFTermExpression which DIF implementation is not able to execute.

It's very likely that this class will contain more create methods in the future.

Method Summary

static DFTermExpression	createExprAndOr(DFOperator operator, List<DFTermExpression> childExpressions, Map<String,Object> options) Creates the AND or OR expression (e.g.
static DFTermExpression	createFieldOperatorValueExpr(DFOperator operator, DFField field, Map<String,Object> options, Object... values) Create the basic "Field operator Value(s)" expression.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

createFieldOperatorValueExpr

public static DFTermExpression createFieldOperatorValueExpr(DFOperator operator,
                                                            DFField field,
                                                            Map<String,Object> options,
                                                            Object... values)

Create the basic "Field operator Value(s)" expression. The number of values depends on the type of operator you use. Some operators are unary (accepts only one operand which is the field... e.g. NULL operator), some other are binary (less than,...) and some accepts many operands (e.g. IN LIST).

Parameters:

operator - The operator

field - The field (will be used as the first operand)

options - Options of the expression, can be null (empty Map is created then)

values - Constant values - the number should match with the operator arity.

Returns:

The new expression term based on the given arguments. Never returns null.

createExprAndOr

public static DFTermExpression createExprAndOr(DFOperator operator,
                                               List<DFTermExpression> childExpressions,
                                               Map<String,Object> options)

Creates the AND or OR expression (e.g. (id = 5) OR (atomcount = 10))

Parameters:

operator - Operator for this expression. Only allowed values are Operators.AND and Operators.OR. You can use Operators.isAndOr(DFOperator) method to test your operator. If other operator is specified this method throws IllegalArgumentException.

childExpressions - One or more child expressions. Currently accepts only DFTermExpressions.

options - Options of the expression

Returns:

The new AND/OR expression term based on the given arguments. Never returns null.