org.apache.activemq.filter
Class BooleanFunctionCallExpr

java.lang.Object
  org.apache.activemq.filter.FunctionCallExpression
      org.apache.activemq.filter.BooleanFunctionCallExpr

All Implemented Interfaces:

BooleanExpression, Expression

public class BooleanFunctionCallExpr
extends FunctionCallExpression
implements BooleanExpression

Function call expression that evaluates to a boolean value. Selector parsing requires BooleanExpression objects for Boolean expressions, such as operands to AND, and as the final result of a selector. This provides that interface for function call expressions that resolve to Boolean values.

If a function can return different types at evaluation-time, the function implementation needs to decide whether it supports casting to Boolean at parse-time.

See Also:

FunctionCallExpression.createFunctionCall(java.lang.String, java.util.List)

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.activemq.filter.FunctionCallExpression

FunctionCallExpression.functionRegistration, FunctionCallExpression.invalidFunctionExpressionException

Field Summary

Fields inherited from class org.apache.activemq.filter.FunctionCallExpression

arguments, filterFunc, functionName, functionRegistry

Constructor Summary

BooleanFunctionCallExpr(String func_name, List<Expression> args)
Constructs a function call expression with the named filter function and arguments, which returns a boolean result.

Method Summary

boolean

matches(MessageEvaluationContext message_ctx) Evaluate the function call expression, in the given context, and return an indication of whether the expression "matches" (i.e. evaluates to true).

Methods inherited from class org.apache.activemq.filter.FunctionCallExpression

createFunctionCall, deregisterFunction, evaluate, getArgument, getNumArguments, registerFunction, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.activemq.filter.Expression

evaluate

Constructor Detail

BooleanFunctionCallExpr

public BooleanFunctionCallExpr(String func_name,
                               List<Expression> args)
                        throws FunctionCallExpression.invalidFunctionExpressionException

Constructs a function call expression with the named filter function and arguments, which returns a boolean result.

Parameters:

func_name - - Name of the filter function to be called when evaluated.

args - - List of argument expressions passed to the function.

Throws:

FunctionCallExpression.invalidFunctionExpressionException

Method Detail

matches

public boolean matches(MessageEvaluationContext message_ctx)
                throws javax.jms.JMSException

Evaluate the function call expression, in the given context, and return an indication of whether the expression "matches" (i.e. evaluates to true).

Specified by:

matches in interface BooleanExpression

Parameters:

message_ctx - - message context against which the expression will be evaluated.

Returns:

the boolean evaluation of the function call expression.

Throws:

javax.jms.JMSException