COM.TIBCO.hawk.config.rbengine.rulebase

Class Operator

java.lang.Object

COM.TIBCO.hawk.config.rbengine.rulebase.Operator

All Implemented Interfaces:

java.io.Serializable

public class Operator
extends java.lang.Object
implements java.io.Serializable

This class is used to build all operators for use as test expressions in Test objects.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	CNAME

Constructor Summary

Constructors

Constructor and Description
Operator(java.lang.String name, java.lang.Object[] operandList) Constructs an operator object.

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o) Tests two Operator objects for equality
java.lang.Object	evaluate() Evaluates the operator and returns the results.
java.lang.String	getDisplayName() Retrieves the operator display name
java.lang.String	getName() Retrieves the operator name
java.lang.Object[]	getOperands() Retrieves the operands
static OperatorDescriptor[]	getOperatorDescriptors() Describes all available operators.
java.lang.String	getType() Retrieves the return type of the operator.
void	setRuleDataContext(RuleDataContext rdc) Sets the RuleDataContext.
java.lang.String	toString() Returns the string representation of this Operator

Methods inherited from class java.lang.Object

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

Field Detail

CNAME

public static java.lang.String CNAME

Constructor Detail

Operator

public Operator(java.lang.String name,
                java.lang.Object[] operandList)

Constructs an operator object.

The supplied operands are checked against the corresponding operator descriptor for validity. This insures that the correct number and types of operands are used.

If an Operator object is supplied as one of the operands, its advertised type is used in the type checking. If its advertised type is java.lang.Object, then it is accepted here and type checking of the result is performed at runtime.

Parameters:

name - The name of the operator being constructed. Cannot be null.

operandList - The operands of the operator. May be null or empty array to indicate no operads.

Throws:

java.lang.IllegalArgumentException - if the named operator is not supported

java.lang.IllegalArgumentException - if the operands in operandList do not match the descriptor of the named operator

java.lang.IllegalArgumentException - if the name is null

java.lang.IllegalArgumentException - if the operandList array contains null elements

Method Detail

getOperatorDescriptors

public static OperatorDescriptor[] getOperatorDescriptors()
                                                   throws OperatorException

Describes all available operators.

Use this static method to identify all available operators and their required operands before constructing an instance of this class.

Throws:

OperatorException

getName

public java.lang.String getName()

Retrieves the operator name

getDisplayName

public java.lang.String getDisplayName()

Retrieves the operator display name

getOperands

public java.lang.Object[] getOperands()

Retrieves the operands

getType

public java.lang.String getType()

Retrieves the return type of the operator.

Returns:

the class name of the type returned by the evaluate() method

evaluate

public java.lang.Object evaluate()
                          throws OperatorException

Evaluates the operator and returns the results. If evaluation occurs successfully, the result is gauranteed to be of the type advertised by the getType() method.

Throws:

OperatorException - if a problem is encountered durring evaluation

setRuleDataContext

public void setRuleDataContext(RuleDataContext rdc)

Sets the RuleDataContext. This method is intended for use by the rules engine which evaluates this operator. The RuleDataContext allows the operators to access the rule engine's data.

When invoked on an instance of this class, this method will be recursively applied to any oprands that also happen to be instances of this class.

equals

public boolean equals(java.lang.Object o)

Tests two Operator objects for equality

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Returns the string representation of this Operator

Overrides:

toString in class java.lang.Object