com.sun.el.lang

Class EvaluationContext

java.lang.Object

javax.el.ELContext

com.sun.el.lang.EvaluationContext

public final class EvaluationContext
extends ELContext

The context for EL expression evaluation. This wrapper ELContext captures the function mapper and the variable mapper at the point when the epxression is parsed, and only for those functions and variable used in the expression.

Constructor Summary

Constructors

Constructor and Description
EvaluationContext(ELContext elContext, FunctionMapper fnMapper, VariableMapper varMapper)

Method Summary

Methods

Modifier and Type	Method and Description
void	addEvaluationListener(EvaluationListener listener) Registers an evaluation listener to the ELContext.
Object	convertToType(Object obj, Class<?> targetType) Converts an object to a specific type.
void	enterLambdaScope(Map<String,Object> args) Installs a Lambda argument map, in preparation for the evaluation of a Lambda expression.
void	exitLambdaScope() Exits the Lambda expression evaluation.
Object	getContext(Class key) Returns the context object associated with the given key.
ELContext	getELContext()
ELResolver	getELResolver() Retrieves the ELResolver associated with this context.
List<EvaluationListener>	getEvaluationListeners() Returns the list of registered evaluation listeners.
FunctionMapper	getFunctionMapper() Retrieves the FunctionMapper associated with this ELContext.
ImportHandler	getImportHandler() Retrieves the ImportHandler associated with this ELContext.
Object	getLambdaArgument(String arg) Retrieves the Lambda argument associated with a formal parameter.
VariableMapper	getVariableMapper() Retrieves the VariableMapper associated with this ELContext.
boolean	isLambdaArgument(String arg) Inquires if the name is a LambdaArgument
boolean	isPropertyResolved() Returns whether an ELResolver has successfully resolved a given (base, property) pair.
void	notifyAfterEvaluation(String expr) Notifies the listeners after an EL expression is evaluated
void	notifyBeforeEvaluation(String expr) Notifies the listeners before an EL expression is evaluated
void	notifyPropertyResolved(Object base, Object property) Notifies the listeners when the (base, property) pair is resolved
void	putContext(Class key, Object contextObject) Associates a context object with this ELContext.
void	setPropertyResolved(boolean resolved) Called to indicate that a ELResolver has successfully resolved a given (base, property) pair.
void	setPropertyResolved(Object base, Object property) Called to indicate that a ELResolver has successfully resolved a given (base, property) pair and to notify the EvaluationListeners.

Methods inherited from class javax.el.ELContext

getLocale, setLocale

Methods inherited from class java.lang.Object

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

Constructor Detail

EvaluationContext

public EvaluationContext(ELContext elContext,
                 FunctionMapper fnMapper,
                 VariableMapper varMapper)

Method Detail

getELContext

public ELContext getELContext()

getFunctionMapper

public FunctionMapper getFunctionMapper()

Description copied from class: ELContext

Retrieves the FunctionMapper associated with this ELContext.

Specified by:

getFunctionMapper in class ELContext

Returns:

The function mapper to be consulted for the resolution of EL functions.

getVariableMapper

public VariableMapper getVariableMapper()

Description copied from class: ELContext

Retrieves the VariableMapper associated with this ELContext.

Specified by:

getVariableMapper in class ELContext

Returns:

The variable mapper to be consulted for the resolution of EL variables.

getContext

public Object getContext(Class key)

Description copied from class: ELContext

Returns the context object associated with the given key.

The ELContext maintains a collection of context objects relevant to the evaluation of an expression. These context objects are used by ELResolvers. This method is used to retrieve the context with the given key from the collection.

By convention, the object returned will be of the type specified by the key. However, this is not required and the key is used strictly as a unique identifier.

Overrides:

getContext in class ELContext

Parameters:

key - The unique identifier that was used to associate the context object with this ELContext.

Returns:

The context object associated with the given key, or null if no such context was found.

getELResolver

public ELResolver getELResolver()

Description copied from class: ELContext

Retrieves the ELResolver associated with this context.

The ELContext maintains a reference to the ELResolver that will be consulted to resolve variables and properties during an expression evaluation. This method retrieves the reference to the resolver.

Once an ELContext is constructed, the reference to the ELResolver associated with the context cannot be changed.

Specified by:

getELResolver in class ELContext

Returns:

The resolver to be consulted for variable and property resolution during expression evaluation.

isPropertyResolved

public boolean isPropertyResolved()

Description copied from class: ELContext

Returns whether an ELResolver has successfully resolved a given (base, property) pair.

The CompositeELResolver checks this property to determine whether it should consider or skip other component resolvers.

Overrides:

isPropertyResolved in class ELContext

Returns:

true if the property has been resolved, or false if not.

See Also:

CompositeELResolver

putContext

public void putContext(Class key,
              Object contextObject)

Description copied from class: ELContext

Associates a context object with this ELContext.

The ELContext maintains a collection of context objects relevant to the evaluation of an expression. These context objects are used by ELResolvers. This method is used to add a context object to that collection.

By convention, the contextObject will be of the type specified by the key. However, this is not required and the key is used strictly as a unique identifier.

Overrides:

putContext in class ELContext

Parameters:

key - The key used by an @{link ELResolver} to identify this context object.

contextObject - The context object to add to the collection.

setPropertyResolved

public void setPropertyResolved(boolean resolved)

Description copied from class: ELContext

Called to indicate that a ELResolver has successfully resolved a given (base, property) pair. Use ELContext.setPropertyResolved(Object, Object) if resolved is true and to notify EvaluationListeners.

The CompositeELResolver checks this property to determine whether it should consider or skip other component resolvers.

Overrides:

setPropertyResolved in class ELContext

Parameters:

resolved - true if the property has been resolved, or false if not.

See Also:

CompositeELResolver

setPropertyResolved

public void setPropertyResolved(Object base,
                       Object property)

Description copied from class: ELContext

Called to indicate that a ELResolver has successfully resolved a given (base, property) pair and to notify the EvaluationListeners.

The CompositeELResolver checks this property to determine whether it should consider or skip other component resolvers.

Overrides:

setPropertyResolved in class ELContext

Parameters:

base - The base object

property - The property object

See Also:

CompositeELResolver

addEvaluationListener

public void addEvaluationListener(EvaluationListener listener)

Description copied from class: ELContext

Registers an evaluation listener to the ELContext.

Overrides:

addEvaluationListener in class ELContext

Parameters:

listener - The listener to be added.

getEvaluationListeners

public List<EvaluationListener> getEvaluationListeners()

Description copied from class: ELContext

Returns the list of registered evaluation listeners.

Overrides:

getEvaluationListeners in class ELContext

Returns:

The list of registered evaluation listeners.

notifyBeforeEvaluation

public void notifyBeforeEvaluation(String expr)

Description copied from class: ELContext

Notifies the listeners before an EL expression is evaluated

Overrides:

notifyBeforeEvaluation in class ELContext

Parameters:

expr - The EL expression string to be evaluated

notifyAfterEvaluation

public void notifyAfterEvaluation(String expr)

Description copied from class: ELContext

Notifies the listeners after an EL expression is evaluated

Overrides:

notifyAfterEvaluation in class ELContext

Parameters:

expr - The EL expression string that has been evaluated

notifyPropertyResolved

public void notifyPropertyResolved(Object base,
                          Object property)

Description copied from class: ELContext

Notifies the listeners when the (base, property) pair is resolved

Overrides:

notifyPropertyResolved in class ELContext

Parameters:

base - The base object

property - The property Object

isLambdaArgument

public boolean isLambdaArgument(String arg)

Description copied from class: ELContext

Inquires if the name is a LambdaArgument

Overrides:

isLambdaArgument in class ELContext

Parameters:

arg - A possible Lambda formal parameter name

Returns:

true if arg is a LambdaArgument, false otherwise.

getLambdaArgument

public Object getLambdaArgument(String arg)

Description copied from class: ELContext

Retrieves the Lambda argument associated with a formal parameter. If the Lambda expression is nested within other Lambda expressions, the arguments for the current Lambda expression is first searched, and if not found, the arguments for the immediate nesting Lambda expression then searched, and so on.

Overrides:

getLambdaArgument in class ELContext

Parameters:

arg - The formal parameter for the Lambda argument

Returns:

The object associated with formal parameter. Null if no object has been associated with the parameter.

enterLambdaScope

public void enterLambdaScope(Map<String,Object> args)

Description copied from class: ELContext

Installs a Lambda argument map, in preparation for the evaluation of a Lambda expression. The arguments in the map will be in scope during the evaluation of the Lambda expression.

Overrides:

enterLambdaScope in class ELContext

Parameters:

args - The Lambda arguments map

exitLambdaScope

public void exitLambdaScope()

Description copied from class: ELContext

Exits the Lambda expression evaluation. The Lambda argument map that was previously installed is removed.

Overrides:

exitLambdaScope in class ELContext

convertToType

public Object convertToType(Object obj,
                   Class<?> targetType)

Description copied from class: ELContext

Converts an object to a specific type. If a custom converter in the ELResolver handles this conversion, it is used. Otherwise the standard coercions is applied.

An ELException is thrown if an error occurs during the conversion.

Overrides:

convertToType in class ELContext

Parameters:

obj - The object to convert.

targetType - The target type for the conversion.

getImportHandler

public ImportHandler getImportHandler()

Description copied from class: ELContext

Retrieves the ImportHandler associated with this ELContext.

Overrides:

getImportHandler in class ELContext

Returns:

The import handler to manage imports of classes and packages.