net.sf.jabb.util.exp

Class CompareExpression

java.lang.Object

net.sf.jabb.util.exp.BooleanExpression

net.sf.jabb.util.exp.CompareExpression

All Implemented Interfaces:

CompareOperation

Direct Known Subclasses:

NumberCompareExpression

public abstract class CompareExpression
extends BooleanExpression
implements CompareOperation

用于得到比较结果

Author:

Zhengmao HU (James)

Field Summary

Fields

Modifier and Type	Field and Description
protected Object	leftOperand
protected int	operation
protected Object	rightOperand

Fields inherited from class net.sf.jabb.util.exp.BooleanExpression

children, FALSE, OPERAND, OPERATOR_AND, OPERATOR_NOT, OPERATOR_OR, operatorType, TRUE

Fields inherited from interface net.sf.jabb.util.exp.CompareOperation

EQ, GE, GT, LE, LT, NE

Constructor Summary

Constructors

Constructor and Description
CompareExpression(Object leftOperand, int operation, Object rightOperand)

Method Summary

Modifier and Type	Method and Description
void	addOperand(BooleanExpression... operands) 给表达式增加运算数
void	addOperand(BooleanExpression operand) 给表达式增加运算数
protected abstract boolean	compare(Object context) 子类应该实现这个方法，利用leftOperand, operation, rightOperand、以及context来 作具体的比较运算，返回确切的结果。
boolean	evaluate(Object context) 获得表达式的结果。子类可以重载这个方法。
String	toString() 转成字符串表示。子类可以重载这个方法。

Methods inherited from class net.sf.jabb.util.exp.BooleanExpression

addOperand, AND, AND, evaluate, HAS, NOT, OR, OR

Methods inherited from class java.lang.Object

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

Field Detail

leftOperand

protected Object leftOperand

rightOperand

protected Object rightOperand

operation

protected int operation

Constructor Detail

CompareExpression

public CompareExpression(Object leftOperand,
                         int operation,
                         Object rightOperand)

Method Detail

addOperand

public void addOperand(BooleanExpression operand)

Description copied from class: BooleanExpression

给表达式增加运算数

Overrides:

addOperand in class BooleanExpression

addOperand

public void addOperand(BooleanExpression... operands)

Description copied from class: BooleanExpression

给表达式增加运算数

Overrides:

addOperand in class BooleanExpression

evaluate

public boolean evaluate(Object context)

Description copied from class: BooleanExpression

获得表达式的结果。子类可以重载这个方法。

Overrides:

evaluate in class BooleanExpression

Returns:

result

compare

protected abstract boolean compare(Object context)

子类应该实现这个方法，利用leftOperand, operation, rightOperand、以及context来 作具体的比较运算，返回确切的结果。

Returns:

the result

toString

public String toString()

Description copied from class: BooleanExpression

转成字符串表示。子类可以重载这个方法。

Overrides:

toString in class BooleanExpression