Package javax.el

Class ExpressionFactory

java.lang.Object

javax.el.ExpressionFactory

public abstract class ExpressionFactory
extends java.lang.Object

Since:

2.1

Constructor Summary

Constructors

Constructor	Description
ExpressionFactory()

Method Summary

Modifier and Type	Method	Description
abstract java.lang.Object	coerceToType(java.lang.Object obj, java.lang.Class<?> expectedType)	Coerce the supplied object to the requested type.
abstract MethodExpression	createMethodExpression(ELContext context, java.lang.String expression, java.lang.Class<?> expectedReturnType, java.lang.Class<?>[] expectedParamTypes)	Create a new method expression instance.
abstract ValueExpression	createValueExpression(java.lang.Object instance, java.lang.Class<?> expectedType)
abstract ValueExpression	createValueExpression(ELContext context, java.lang.String expression, java.lang.Class<?> expectedType)	Create a new value expression.
static ExpressionFactory	newInstance()	Create a new ExpressionFactory.
static ExpressionFactory	newInstance(java.util.Properties properties)	Create a new ExpressionFactory passing in the provided Properties.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpressionFactory

public ExpressionFactory()

Method Detail

newInstance

public static ExpressionFactory newInstance()

Create a new ExpressionFactory. The class to use is determined by the following search order:

1. services API (META-INF/services/javax.el.ExpressionFactory)
2. $JRE_HOME/lib/el.properties - key javax.el.ExpressionFactory
3. javax.el.ExpressionFactory
4. Platform default implementation - org.apache.el.ExpressionFactoryImpl

Returns:

the new ExpressionFactory

newInstance

public static ExpressionFactory newInstance(java.util.Properties properties)

Create a new ExpressionFactory passing in the provided Properties. Search order is the same as newInstance().

Parameters:

properties - the properties to be passed to the new instance (may be null)

Returns:

the new ExpressionFactory

createValueExpression

public abstract ValueExpression createValueExpression(ELContext context,
                                                      java.lang.String expression,
                                                      java.lang.Class<?> expectedType)

Create a new value expression.

Parameters:

context - The EL context for this evaluation

expression - The String representation of the value expression

expectedType - The expected type of the result of evaluating the expression

Returns:

A new value expression formed from the input parameters

Throws:

java.lang.NullPointerException - If the expected type is null

ELException - If there are syntax errors in the provided expression

createValueExpression

public abstract ValueExpression createValueExpression(java.lang.Object instance,
                                                      java.lang.Class<?> expectedType)

createMethodExpression

public abstract MethodExpression createMethodExpression(ELContext context,
                                                        java.lang.String expression,
                                                        java.lang.Class<?> expectedReturnType,
                                                        java.lang.Class<?>[] expectedParamTypes)

Create a new method expression instance.

Parameters:

context - The EL context for this evaluation

expression - The String representation of the method expression

expectedReturnType - The expected type of the result of invoking the method

expectedParamTypes - The expected types of the input parameters

Returns:

A new method expression formed from the input parameters.

Throws:

java.lang.NullPointerException - If the expected parameters types are null

ELException - If there are syntax errors in the provided expression

coerceToType

public abstract java.lang.Object coerceToType(java.lang.Object obj,
                                              java.lang.Class<?> expectedType)

Coerce the supplied object to the requested type.

Parameters:

obj - The object to be coerced

expectedType - The type to which the object should be coerced

Returns:

An instance of the requested type.

Throws:

ELException - If the conversion fails