javax.el

Class ELManager

java.lang.Object

javax.el.ELManager

public class ELManager
extends Object

Manages EL parsing and evaluation environment. The ELManager maintains an instance of ExpressionFactory and StandardELContext, for parsing and evaluating EL expressions.

Since:

EL 3.0

Constructor Summary

Constructors

Constructor and Description
ELManager()

Method Summary

Methods

Modifier and Type	Method and Description
void	addBeanNameResolver(BeanNameResolver bnr) Register a BeanNameResolver.
void	addELResolver(ELResolver elr) Add an user defined ELResolver to the list of ELResolvers.
void	addEvaluationListener(EvaluationListener listener) Register an evaluation listener.
Object	defineBean(String name, Object bean) Define a bean in the local bean repository
StandardELContext	getELContext() Return the ELContext used for parsing and evaluating EL expressions.
static ExpressionFactory	getExpressionFactory() Return the ExpressionFactory instance used for EL evaluations.
void	importClass(String className) Import a class.
void	importPackage(String packageName) Import a package.
void	importStatic(String staticMemberName) Import a static field or method.
void	mapFunction(String prefix, String function, Method meth) Maps a static method to an EL function.
ELContext	setELContext(ELContext context) Set the ELContext used for parsing and evaluating EL expressions.
void	setVariable(String variable, ValueExpression expression) Assign a ValueExpression to an EL variable, replacing any previous assignment to the same variable.

Methods inherited from class java.lang.Object

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

Constructor Detail

ELManager

public ELManager()

Method Detail

getExpressionFactory

public static ExpressionFactory getExpressionFactory()

Return the ExpressionFactory instance used for EL evaluations.

Returns:

The ExpressionFactory

getELContext

public StandardELContext getELContext()

Return the ELContext used for parsing and evaluating EL expressions. If there is currently no ELContext, a default instance of StandardELContext is returned.

Returns:

The ELContext used for parsing and evaluating EL expressions..

setELContext

public ELContext setELContext(ELContext context)

Set the ELContext used for parsing and evaluating EL expressions. The supplied ELContext will not be modified, except for the context object map.

Parameters:

context - The new ELContext.

Returns:

The previous ELContext, null if none.

addBeanNameResolver

public void addBeanNameResolver(BeanNameResolver bnr)

Register a BeanNameResolver. Construct a BeanNameELResolver with the BeanNameResolver and add it to the list of ELResolvers. Once registered, the BeanNameResolver cannot be removed.

Parameters:

bnr - The BeanNameResolver to be registered.

addELResolver

public void addELResolver(ELResolver elr)

Add an user defined ELResolver to the list of ELResolvers. Can be called multiple times. The new ELResolver is placed ahead of the default ELResolvers. The list of the ELResolvers added this way are ordered chronologically.

Parameters:

elr - The ELResolver to be added to the list of ELResolvers in ELContext.

See Also:

StandardELContext.addELResolver(javax.el.ELResolver)

mapFunction

public void mapFunction(String prefix,
               String function,
               Method meth)

Maps a static method to an EL function.

Parameters:

prefix - The namespace of the functions, can be "".

function - The name of the function.

meth - The static method to be invoked when the function is used.

setVariable

public void setVariable(String variable,
               ValueExpression expression)

Assign a ValueExpression to an EL variable, replacing any previous assignment to the same variable. The assignment for the variable is removed if the expression is null.

Parameters:

variable - The variable name

expression - The ValueExpression to be assigned to the variable.

importStatic

public void importStatic(String staticMemberName)
                  throws ELException

Import a static field or method. The class of the static member must be loadable from the classloader, at class resolution time.

Parameters:

staticMemberName - The full class name of the class to be imported

Throws:

ELException - if the name is not a full class name.

importClass

public void importClass(String className)
                 throws ELException

Import a class. The imported class must be loadable from the classloader at the expression evaluation time.

Parameters:

className - The full class name of the class to be imported

Throws:

ELException - if the name is not a full class name.

importPackage

public void importPackage(String packageName)

Import a package. At the expression evaluation time, the imported package name will be used to construct the full class name, which will then be used to load the class. Inherently, this is less efficient than importing a class.

Parameters:

packageName - The package name to be imported

defineBean

public Object defineBean(String name,
                Object bean)

Define a bean in the local bean repository

Parameters:

name - The name of the bean

bean - The bean instance to be defined. If null, the definition of the bean is removed.

addEvaluationListener

public void addEvaluationListener(EvaluationListener listener)

Register an evaluation listener.

Parameters:

listener - The evaluation listener to be added.