Package org.apache.qpid.jms.selector.filter

Class ComparisonExpression

java.lang.Object

org.apache.qpid.jms.selector.filter.BinaryExpression

org.apache.qpid.jms.selector.filter.ComparisonExpression

All Implemented Interfaces:

BooleanExpression, Expression

public abstract class ComparisonExpression
extends BinaryExpression
implements BooleanExpression

A filter performing a comparison of two objects

Field Summary

Fields inherited from class org.apache.qpid.jms.selector.filter.BinaryExpression

left, right

Constructor Summary

Constructors

Constructor	Description
ComparisonExpression(Expression left, Expression right)

Method Summary

Modifier and Type	Method	Description
protected abstract boolean	asBoolean(int answer)
static void	checkEqualOperand(Expression expr)	Validates that the expression can be used in == or <> expressions.
static void	checkLessThanOperand(Expression expr)	Only Numeric expressions can be used in >, >=, < or <= expressions.
protected Boolean	compare(Comparable lv, Comparable rv)
static BooleanExpression	createBetween(Expression value, Expression left, Expression right)
static BooleanExpression	createEqual(Expression left, Expression right)
static BooleanExpression	createGreaterThan(Expression left, Expression right)
static BooleanExpression	createGreaterThanEqual(Expression left, Expression right)
static BooleanExpression	createInFilter(Expression left, List elements)
static BooleanExpression	createIsNotNull(Expression left)
static BooleanExpression	createIsNull(Expression left)
static BooleanExpression	createLessThan(Expression left, Expression right)
static BooleanExpression	createLessThanEqual(Expression left, Expression right)
static BooleanExpression	createLike(Expression left, String right, String escape)
static BooleanExpression	createNotBetween(Expression value, Expression left, Expression right)
static BooleanExpression	createNotEqual(Expression left, Expression right)
static BooleanExpression	createNotInFilter(Expression left, List elements)
static BooleanExpression	createNotLike(Expression left, String right, String escape)
Object	evaluate(Filterable message)
boolean	matches(Filterable message)

Methods inherited from class org.apache.qpid.jms.selector.filter.BinaryExpression

equals, getExpressionSymbol, getLeft, getRight, hashCode, setLeft, setRight, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ComparisonExpression

public ComparisonExpression(Expression left,
                            Expression right)

Method Detail

createBetween

public static BooleanExpression createBetween(Expression value,
                                              Expression left,
                                              Expression right)

createNotBetween

public static BooleanExpression createNotBetween(Expression value,
                                                 Expression left,
                                                 Expression right)

createLike

public static BooleanExpression createLike(Expression left,
                                           String right,
                                           String escape)

createNotLike

public static BooleanExpression createNotLike(Expression left,
                                              String right,
                                              String escape)

createInFilter

public static BooleanExpression createInFilter(Expression left,
                                               List elements)

createNotInFilter

public static BooleanExpression createNotInFilter(Expression left,
                                                  List elements)

createIsNull

public static BooleanExpression createIsNull(Expression left)

createIsNotNull

public static BooleanExpression createIsNotNull(Expression left)

createNotEqual

public static BooleanExpression createNotEqual(Expression left,
                                               Expression right)

createEqual

public static BooleanExpression createEqual(Expression left,
                                            Expression right)

createGreaterThan

public static BooleanExpression createGreaterThan(Expression left,
                                                  Expression right)

createGreaterThanEqual

public static BooleanExpression createGreaterThanEqual(Expression left,
                                                       Expression right)

createLessThan

public static BooleanExpression createLessThan(Expression left,
                                               Expression right)

createLessThanEqual

public static BooleanExpression createLessThanEqual(Expression left,
                                                    Expression right)

checkLessThanOperand

public static void checkLessThanOperand(Expression expr)

Only Numeric expressions can be used in >, >=, < or <= expressions.

Parameters:

expr - The expression to evaluate.

checkEqualOperand

public static void checkEqualOperand(Expression expr)

Validates that the expression can be used in == or <> expressions. Cannot not be NULL TRUE or FALSE literals.

Parameters:

expr - The expression to evaluate.

evaluate

public Object evaluate(Filterable message)
                throws FilterException

Specified by:

evaluate in interface Expression

Parameters:

message - The message that is being selected against.

Returns:

the value of this expression

Throws:

FilterException - if an error occurs during evaluation.

compare

protected Boolean compare(Comparable lv,
                          Comparable rv)

asBoolean

protected abstract boolean asBoolean(int answer)

matches

public boolean matches(Filterable message)
                throws FilterException

Specified by:

matches in interface BooleanExpression

Returns:

true if the expression evaluates to Boolean.TRUE.

Throws:

FilterException