org.mule.api.expression
Interface ExpressionManager

All Known Implementing Classes:

DefaultExpressionManager

public interface ExpressionManager

Provides universal access for evaluating expressions embedded in Mule configurations, such as Xml, Java, scripting and annotations.

Users can register or unregister ExpressionEvaluator through this interface.

Field Summary

static String	DEFAULT_EXPRESSION_POSTFIX
static String	DEFAULT_EXPRESSION_PREFIX

Method Summary

void	clearEnrichers() Clears all registered enrichers from the manager.
void	clearEvaluators() Clears all registered evaluators from the manager.
void	enrich(String expression, MuleEvent message, Object object)
void	enrich(String expression, MuleMessage message, Object object) Deprecated.
void	enrich(String expression, String enricher, MuleMessage message, Object object) Enriches the current message
Object	evaluate(String expression, MuleEvent event)
Object	evaluate(String expression, MuleEvent event, boolean failIfNull)
Object	evaluate(String expression, MuleMessage message) Deprecated.
Object	evaluate(String expression, MuleMessage message, boolean failIfNull) Deprecated.
Object	evaluate(String expression, String evaluator, MuleMessage message, boolean failIfNull) Evaluates the given expression.
boolean	evaluateBoolean(String expression, MuleEvent event)
boolean	evaluateBoolean(String expression, MuleEvent event, boolean nullReturnsTrue, boolean nonBooleanReturnsTrue)
boolean	evaluateBoolean(String expression, MuleMessage message) Deprecated.
boolean	evaluateBoolean(String expression, MuleMessage message, boolean nullReturnsTrue, boolean nonBooleanReturnsTrue) Deprecated.
boolean	evaluateBoolean(String expression, String evaluator, MuleMessage message) Evaluates the given expression resolving the result of the evaluation to a boolean.
boolean	evaluateBoolean(String expression, String evaluator, MuleMessage message, boolean nullReturnsTrue, boolean nonBooleanReturnsTrue) Evaluates the given expression resolving the result of the evaluation to a boolean.
boolean	isEnricherRegistered(String name) Checks whether an enricher is registered with the manager
boolean	isEvaluatorRegistered(String name) Checks whether an evaluator is registered with the manager
boolean	isExpression(String string) Determines if the string is an expression.
boolean	isValidExpression(String expression) Determines if the expression is valid or not.
String	parse(String expression, MuleEvent event)
String	parse(String expression, MuleEvent event, boolean failIfNull)
String	parse(String expression, MuleMessage message) Deprecated.
String	parse(String expression, MuleMessage message, boolean failIfNull) Deprecated.
void	registerEnricher(ExpressionEnricher enricher)
void	registerEvaluator(ExpressionEvaluator evaluator)
ExpressionEnricher	unregisterEnricher(String name) Removes the enricher with the given name
ExpressionEvaluator	unregisterEvaluator(String name) Removes the evaluator with the given name
void	validateExpression(String expression) Determines if the expression is valid or not.

Field Detail

DEFAULT_EXPRESSION_PREFIX

static final String DEFAULT_EXPRESSION_PREFIX

See Also:

Constant Field Values

DEFAULT_EXPRESSION_POSTFIX

static final String DEFAULT_EXPRESSION_POSTFIX

See Also:

Constant Field Values

Method Detail

registerEvaluator

void registerEvaluator(ExpressionEvaluator evaluator)

isEvaluatorRegistered

boolean isEvaluatorRegistered(String name)

Checks whether an evaluator is registered with the manager

Parameters:

name - the name of the expression evaluator

Returns:

true if the evaluator is registered with the manager, false otherwise

unregisterEvaluator

ExpressionEvaluator unregisterEvaluator(String name)

Removes the evaluator with the given name

Parameters:

name - the name of the evaluator to remove

Returns:

the evaluator that was removed. This will be null if the evaluator was not registered

registerEnricher

void registerEnricher(ExpressionEnricher enricher)

isEnricherRegistered

boolean isEnricherRegistered(String name)

Checks whether an enricher is registered with the manager

Parameters:

name - the name of the expression enricher

Returns:

true if the enricher is registered with the manager, false otherwise

unregisterEnricher

ExpressionEnricher unregisterEnricher(String name)

Removes the enricher with the given name

Parameters:

name - the name of the enricher to remove

Returns:

the enricher that was removed. This will be null if the enricher was not registered

evaluate

@Deprecated
Object evaluate(String expression,
                           MuleMessage message)
                throws ExpressionRuntimeException

Deprecated.

Evaluates the given expression. The expression should be a single expression definition with or without enclosing braces. i.e. "context:serviceName" and "#[context:serviceName]" are both valid. For situations where one or more expressions need to be parsed within a single text, the parse(String,org.mule.api.MuleMessage,boolean) method should be used since it will iterate through all expressions in a string.

Parameters:

expression - a single expression i.e. xpath://foo

message - The current message being processed

Returns:

the result of the evaluation

Throws:

ExpressionRuntimeException - if the expression is invalid, or a null is found for the expression and 'failIfNull is set to true.

evaluate

Object evaluate(String expression,
                MuleEvent event)
                throws ExpressionRuntimeException

Throws:

ExpressionRuntimeException

evaluate

@Deprecated
Object evaluate(String expression,
                           MuleMessage message,
                           boolean failIfNull)
                throws ExpressionRuntimeException

Deprecated.

Evaluates the given expression. The expression should be a single expression definition with or without enclosing braces. i.e. "context:serviceName" and "#[context:serviceName]" are both valid. For situations where one or more expressions need to be parsed within a single text, the parse(String,org.mule.api.MuleMessage,boolean) method should be used since it will iterate through all expressions in a string.

Parameters:

expression - a single expression i.e. xpath://foo

message - The current message being processed

failIfNull - determines if an exception should be thrown if expression could not be evaluated or returns null. @return the result of the evaluation

Returns:

the parsered expression string

Throws:

ExpressionRuntimeException - if the expression is invalid, or a null is found for the expression and 'failIfNull is set to true.

evaluate

Object evaluate(String expression,
                MuleEvent event,
                boolean failIfNull)
                throws ExpressionRuntimeException

Throws:

ExpressionRuntimeException

evaluate

Object evaluate(String expression,
                String evaluator,
                MuleMessage message,
                boolean failIfNull)
                throws ExpressionRuntimeException

Evaluates the given expression. The expression should be a single expression definition with or without enclosing braces. i.e. "context:serviceName" and "#[context:serviceName]" are both valid. For situations where one or more expressions need to be parsed within a single text, the parse(String,org.mule.api.MuleMessage,boolean) method should be used since it will iterate through all expressions in a string.

Parameters:

expression - one or more expressions ebedded in a literal string i.e. "Value is #[xpath://foo] other value is #[header:foo]."

evaluator - the evaluator to use when executing the expression

message - The current message being processed

failIfNull - determines if an exception should be thrown if expression could not be evaluated or returns null. @return the result of the evaluation

Returns:

the parsered expression string

Throws:

ExpressionRuntimeException - if the expression is invalid, or a null is found for the expression and 'failIfNull is set to true.

evaluateBoolean

boolean evaluateBoolean(String expression,
                        String evaluator,
                        MuleMessage message)
                        throws ExpressionRuntimeException

Evaluates the given expression resolving the result of the evaluation to a boolean. The expression should be a single expression definition with or without enclosing braces. i.e. "context:serviceName" and "#[context:serviceName]" are both valid.

Parameters:

expression - a single expression i.e. header:foo=bar

evaluator - the evaluator to use when executing the expression

message - The current message being processed

Throws:

ExpressionRuntimeException

evaluateBoolean

@Deprecated
boolean evaluateBoolean(String expression,
                                   MuleMessage message)
                        throws ExpressionRuntimeException

Deprecated.

Evaluates the given expression resolving the result of the evaluation to a boolean. The expression should be a single expression definition with or without enclosing braces. i.e. "context:serviceName" and "#[context:serviceName]" are both valid.

Parameters:

expression - a single expression i.e. header:foo=bar

message - The current message being processed

Throws:

ExpressionRuntimeException

evaluateBoolean

boolean evaluateBoolean(String expression,
                        MuleEvent event)
                        throws ExpressionRuntimeException

Throws:

ExpressionRuntimeException

evaluateBoolean

boolean evaluateBoolean(String expression,
                        String evaluator,
                        MuleMessage message,
                        boolean nullReturnsTrue,
                        boolean nonBooleanReturnsTrue)
                        throws ExpressionRuntimeException

Evaluates the given expression resolving the result of the evaluation to a boolean. The expression should be a single expression definition with or without enclosing braces. i.e. "context:serviceName" and "#[context:serviceName]" are both valid.

Parameters:

expression - a single expression i.e. header:foo=bar

evaluator - the evaluator to use when executing the expression

message - The current message being processed

nullReturnsTrue - determines if true should be returned if the result of the evaluation is null

nonBooleanReturnsTrue - determines if true should returned if the result is not null but isn't recognised as a boolean

Throws:

ExpressionRuntimeException

evaluateBoolean

@Deprecated
boolean evaluateBoolean(String expression,
                                   MuleMessage message,
                                   boolean nullReturnsTrue,
                                   boolean nonBooleanReturnsTrue)
                        throws ExpressionRuntimeException

Deprecated.

Evaluates the given expression resolving the result of the evaluation to a boolean. The expression should be a single expression definition with or without enclosing braces. i.e. "context:serviceName" and "#[context:serviceName]" are both valid.

Parameters:

expression - a single expression i.e. header:foo=bar

message - The current message being processed

nullReturnsTrue - determines if true should be returned if the result of the evaluation is null

nonBooleanReturnsTrue - determines if true should returned if the result is not null but isn't recognised as a boolean

Throws:

ExpressionRuntimeException

evaluateBoolean

boolean evaluateBoolean(String expression,
                        MuleEvent event,
                        boolean nullReturnsTrue,
                        boolean nonBooleanReturnsTrue)
                        throws ExpressionRuntimeException

Throws:

ExpressionRuntimeException

enrich

@Deprecated
void enrich(String expression,
                       MuleMessage message,
                       Object object)

Deprecated.

Enriches the current message using

Parameters:

expression - a single expression i.e. header://foo that defines how the message shoud be enriched

message - The current message being processed that will be enriched

object - The object that will be used to enrich the message

enrich

void enrich(String expression,
            MuleEvent message,
            Object object)

enrich

void enrich(String expression,
            String enricher,
            MuleMessage message,
            Object object)

Enriches the current message

Parameters:

expression - a single expression i.e. header://foo that defines how the message shoud be enriched

enricher - the enricher to use when executing the expression

message - The current message being processed that will be enriched

object - The object that will be used to enrich the message

parse

@Deprecated
String parse(String expression,
                        MuleMessage message)
             throws ExpressionRuntimeException

Deprecated.

Evaluates expressions in a given string. This method will iterate through each expression and evaluate it. If a user needs to evaluate a single expression they can use evaluate(String,org.mule.api.MuleMessage,boolean).

Parameters:

expression - one or more expressions ebedded in a literal string i.e. "Value is #[xpath://foo] other value is #[header:foo]."

message - The current message being processed

Returns:

the result of the evaluation

Throws:

ExpressionRuntimeException - if the expression is invalid, or a null is found for the expression and 'failIfNull is set to true.

parse

String parse(String expression,
             MuleEvent event)
             throws ExpressionRuntimeException

Throws:

ExpressionRuntimeException

parse

@Deprecated
String parse(String expression,
                        MuleMessage message,
                        boolean failIfNull)
             throws ExpressionRuntimeException

Deprecated.

Evaluates expressions in a given string. This method will iterate through each expression and evaluate it. If a user needs to evaluate a single expression they can use evaluate(String,org.mule.api.MuleMessage,boolean).

Parameters:

expression - one or more expressions ebedded in a literal string i.e. "Value is #[xpath://foo] other value is #[header:foo]."

message - The current message being processed

failIfNull - determines if an exception should be thrown if expression could not be evaluated or returns null. @return the result of the evaluation

Returns:

the parsered expression string

Throws:

ExpressionRuntimeException - if the expression is invalid, or a null is found for the expression and 'failIfNull is set to true.

parse

String parse(String expression,
             MuleEvent event,
             boolean failIfNull)
             throws ExpressionRuntimeException

Throws:

ExpressionRuntimeException

clearEvaluators

void clearEvaluators()

Clears all registered evaluators from the manager.

clearEnrichers

void clearEnrichers()

Clears all registered enrichers from the manager.

isValidExpression

boolean isValidExpression(String expression)

Determines if the expression is valid or not. This method will validate a single expression or expressions embedded in a string. The expression must either be a well formed expression evaluator i.e. #[bean:user] or must be a valid expression language expression.

Parameters:

expression - the expression to validate

Returns:

true if the expression evaluator is recognised

validateExpression

void validateExpression(String expression)
                        throws InvalidExpressionException

Determines if the expression is valid or not. This method will validate a single expression or expressions embedded in a string. The expression must either be a well formed expression evaluator i.e. #[bean:user] or must be a valid expression language expression.

Parameters:

expression - the expression to validate

Throws:

InvalidExpressionException - if the expression is invalid, including information about the position and fault

Since:

3.0

isExpression

boolean isExpression(String string)

Determines if the string is an expression. This method will validate that the string contains either the expression prefix (malformed) or a full expression. This isn't full proof but catches most error cases

Parameters:

string - is this string an expression string

Returns:

true if the string contains an expression

Since:

3.0