ariba.util.fieldvalue
Class Expression

java.lang.Object
  ariba.util.fieldvalue.Expression

Direct Known Subclasses:

AribaExprEvaluator.Expression

public abstract class Expression
extends Object

Abstract representation of an expression in an unspecified expression language.

Constructor Summary

Expression()

Method Summary

Object	evaluate(Object object) Calls evaluate(Object,FieldValue) with a null FieldValue.
abstract Object	evaluate(Object object, FieldValue fieldValueProtocol) Evaluates this against object using the supplied fieldValueProtocol to object field values from object during the evaluation.
abstract Collection	getFieldPaths() Returns the collection of fields paths referenced in this expression.
abstract String	toString() Returns the String representation of this.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Expression

public Expression()

Method Detail

evaluate

public abstract Object evaluate(Object object,
                                FieldValue fieldValueProtocol)
                         throws ExpressionEvaluatorException

Evaluates this against object using the supplied fieldValueProtocol to object field values from object during the evaluation. (Expressions may refer to fields of the objects against which they are evaluated.)

Parameters:

object - the object against which to evaluate this; may be null but in this case cannot have any fields dereferenced against it

fieldValueProtocol - the protocol to use to obtain field values from object during the evaulation; may be null in which case the default field value protocol for the class of object is used (see FieldValue.get(Object))

Throws:

ExpressionEvaluatorException

getFieldPaths

public abstract Collection getFieldPaths()

Returns the collection of fields paths referenced in this expression.

evaluate

public final Object evaluate(Object object)
                      throws ExpressionEvaluatorException

Calls evaluate(Object,FieldValue) with a null FieldValue.

Throws:

ExpressionEvaluatorException

toString

public abstract String toString()

Returns the String representation of this. The returned string should be the String that was used when this was ExpressionEvaluator.compile(java.lang.String) (ideally) or at least the string should be equivalent in the sense that it would result in the creation of an identically behaving expression.

Overrides:

toString in class Object