Class EnvironmentAccessor

java.lang.Object

org.springframework.context.expression.EnvironmentAccessor

All Implemented Interfaces:

PropertyAccessor, TargetedAccessor

public class EnvironmentAccessor
extends Object
implements PropertyAccessor

Read-only SpEL PropertyAccessor that knows how to retrieve properties of a Spring Environment instance.

Since:

3.1

Author:

Chris Beams

Constructor Summary

Constructors

Constructor	Description
EnvironmentAccessor()

Method Summary

Modifier and Type	Method	Description
boolean	canRead(EvaluationContext context, @Nullable Object target, String name)	Called to determine if this property accessor is able to read a specified property on a specified target object.
boolean	canWrite(EvaluationContext context, @Nullable Object target, String name)	Read-only: returns false.
Class<?>[]	getSpecificTargetClasses()	Get the set of classes for which this accessor should be called.
TypedValue	read(EvaluationContext context, @Nullable Object target, String name)	Access the given target object by resolving the given property name against the given target environment.
void	write(EvaluationContext context, @Nullable Object target, String name, @Nullable Object newValue)	Called to write to a property on a specified target object.

Methods inherited from class Object

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

Constructor Details

EnvironmentAccessor

public EnvironmentAccessor()

Method Details

getSpecificTargetClasses

public Class<?>[] getSpecificTargetClasses()

Description copied from interface: TargetedAccessor

Get the set of classes for which this accessor should be called.

Returning null or an empty array indicates this is a generic accessor that can be called in an attempt to access an element on any type.

Specified by:

getSpecificTargetClasses in interface TargetedAccessor

Returns:

an array of classes that this accessor is suitable for (or null or an empty array if a generic accessor)

canRead

public boolean canRead(EvaluationContext context,
 @Nullable Object target,
 String name)
                throws AccessException

Description copied from interface: PropertyAccessor

Called to determine if this property accessor is able to read a specified property on a specified target object.

Specified by:

canRead in interface PropertyAccessor

Parameters:

context - the evaluation context in which the access is being attempted

target - the target object upon which the property is being accessed

name - the name of the property being accessed

Returns:

true if this property accessor is able to read the property

Throws:

AccessException - if there is any problem determining whether the property can be read

read

public TypedValue read(EvaluationContext context,
 @Nullable Object target,
 String name)
                throws AccessException

Access the given target object by resolving the given property name against the given target environment.

Specified by:

read in interface PropertyAccessor

Parameters:

context - the evaluation context in which the access is being attempted

target - the target object upon which the property is being accessed

name - the name of the property being accessed

Returns:

a TypedValue object wrapping the property value read and a type descriptor for it

Throws:

AccessException - if there is any problem reading the property value

canWrite

public boolean canWrite(EvaluationContext context,
 @Nullable Object target,
 String name)
                 throws AccessException

Read-only: returns false.

Specified by:

canWrite in interface PropertyAccessor

Parameters:

context - the evaluation context in which the access is being attempted

target - the target object upon which the property is being accessed

name - the name of the property being accessed

Returns:

true if this property accessor is able to write to the property

Throws:

AccessException - if there is any problem determining whether the property can be written to

write

public void write(EvaluationContext context,
 @Nullable Object target,
 String name,
 @Nullable Object newValue)
           throws AccessException

Description copied from interface: PropertyAccessor

Called to write to a property on a specified target object.

Should only succeed if PropertyAccessor.canWrite(EvaluationContext, Object, String) also returns true.

Specified by:

write in interface PropertyAccessor

Parameters:

context - the evaluation context in which the access is being attempted

target - the target object upon which the property is being accessed

name - the name of the property being accessed

newValue - the new value for the property

Throws:

AccessException - if there is any problem writing to the property value