org.hawkular.apm.api.internal.actions

Class ExpressionHandler

java.lang.Object

org.hawkular.apm.api.internal.actions.ExpressionHandler

Direct Known Subclasses:

DataExpressionHandler, LiteralExpressionHandler

public abstract class ExpressionHandler
extends Object

This abstract class provides the base implementation for expression handlers.

Author:

gbrown

Constructor Summary

Constructors

Constructor and Description
ExpressionHandler(Expression expression)

Method Summary

Modifier and Type	Method and Description
abstract String	evaluate(Trace trace, Node node, Direction direction, Map<String,?> headers, Object[] values) This method evaluates the supplied information against this expression.
Expression	getExpression()
abstract List<ConfigMessage>	init(Processor processor, ProcessorAction action, boolean predicate) This method initialises the expression handler.
boolean	isUsesContent() This method indicates whether the expression uses content.
boolean	isUsesHeaders() This method indicates whether the expression uses headers.
void	setExpression(Expression expression)
abstract boolean	test(Trace trace, Node node, Direction direction, Map<String,?> headers, Object[] values) This method evaluates the supplied information against this expression representing a predicate.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpressionHandler

public ExpressionHandler(Expression expression)

Method Detail

getExpression

public Expression getExpression()

Returns:

the expression

setExpression

public void setExpression(Expression expression)

Parameters:

expression - the expression to set

isUsesHeaders

public boolean isUsesHeaders()

This method indicates whether the expression uses headers.

Returns:

Whether headers are used

isUsesContent

public boolean isUsesContent()

This method indicates whether the expression uses content.

Returns:

Whether content is used

init

public abstract List<ConfigMessage> init(Processor processor,
                                         ProcessorAction action,
                                         boolean predicate)

This method initialises the expression handler.

Parameters:

processor - The processor

action - The action

predicate - Whether the expression is a predicate

test

public abstract boolean test(Trace trace,
                             Node node,
                             Direction direction,
                             Map<String,?> headers,
                             Object[] values)

This method evaluates the supplied information against this expression representing a predicate.

Parameters:

trace - The trace

node - The node

direction - The direction

headers - The optional headers

values - The values

Returns:

The predicate result

evaluate

public abstract String evaluate(Trace trace,
                                Node node,
                                Direction direction,
                                Map<String,?> headers,
                                Object[] values)

This method evaluates the supplied information against this expression.

Parameters:

trace - The trace

node - The node

direction - The direction

headers - The optional headers

values - The values

Returns:

The evaluated result