org.josql.expressions
Class BooleanExpression

java.lang.Object
  org.josql.expressions.Expression
      org.josql.expressions.ValueExpression
          org.josql.expressions.BooleanExpression

public class BooleanExpression
extends ValueExpression

This class represents a "boolean" expression, either true or false.

Constructor Summary

BooleanExpression()

Method Summary

Object	evaluate(Object o, Query q) Get the value of this boolean.
Class	getExpectedReturnType(Query q) Get the expected return type.
Object	getValue(Object o, Query q) Get the value of this boolean.
boolean	hasFixedResult(Query q) Always returns true since it represents a constant.
void	init(Query q) Init this expression.
boolean	isTrue(Object o, Query q) Returns whether this expression is true or false.
void	setValue(Boolean b)
String	toString() Returns a string version of this expression.

Methods inherited from class org.josql.expressions.Expression

isBracketed, setBracketed

Methods inherited from class java.lang.Object

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

Constructor Detail

BooleanExpression

public BooleanExpression()

Method Detail

hasFixedResult

public boolean hasFixedResult(Query q)

Always returns true since it represents a constant.

Specified by:

hasFixedResult in class Expression

Parameters:

q - The Query object.

Returns:

true always.

toString

public String toString()

Returns a string version of this expression. Basically returns: true | false.

Specified by:

toString in class Expression

Returns:

A string version of this expression.

getExpectedReturnType

public Class getExpectedReturnType(Query q)

Get the expected return type.

Specified by:

getExpectedReturnType in class Expression

Parameters:

q - The Query object.

Returns:

Always returns: java.lang.Boolean.TYPE.

init

public void init(Query q)

Init this expression. Actually does nothing since it is a constant.

Specified by:

init in class Expression

Parameters:

q - The Query object.

setValue

public void setValue(Boolean b)

isTrue

public boolean isTrue(Object o,
                      Query q)

Returns whether this expression is true or false.

Specified by:

isTrue in class Expression

Parameters:

o - The current object, not used in this method.

q - The Query object, not used in this method.

Returns:

The value of this expression.

getValue

public Object getValue(Object o,
                       Query q)

Get the value of this boolean.

Overrides:

getValue in class ValueExpression

Parameters:

o - The current object, not used in this method.

q - The Query object, not used in this method.

Returns:

The value of this expression.

evaluate

public Object evaluate(Object o,
                       Query q)

Get the value of this boolean.

Specified by:

evaluate in class ValueExpression

Parameters:

o - The current object, not used in this method.

q - The Query object, not used in this method.

Returns:

The value of this expression.