org.springframework.cache.interceptor

Class CacheEvaluationContext

java.lang.Object

org.springframework.expression.spel.support.StandardEvaluationContext

org.springframework.context.expression.MethodBasedEvaluationContext

org.springframework.cache.interceptor.CacheEvaluationContext

All Implemented Interfaces:

EvaluationContext

class CacheEvaluationContext
extends MethodBasedEvaluationContext

Cache specific evaluation context that adds a method parameters as SpEL variables, in a lazy manner. The lazy nature eliminates unneeded parsing of classes byte code for parameter discovery.

Also define a set of "unavailable variables" (i.e. variables that should lead to an exception right the way when they are accessed). This can be useful to verify a condition does not match even when not all potential variables are present.

To limit the creation of objects, an ugly constructor is used (rather then a dedicated 'closure'-like class for deferred execution).

Since:

3.1

Author:

Costin Leau, Stephane Nicoll

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.List<java.lang.String>	unavailableVariables

Constructor Summary

Constructors

Constructor and Description
CacheEvaluationContext(java.lang.Object rootObject, java.lang.reflect.Method method, java.lang.Object[] args, ParameterNameDiscoverer paramDiscoverer)

Method Summary

Modifier and Type	Method and Description
void	addUnavailableVariable(java.lang.String name) Add the specified variable name as unavailable for that context.
java.lang.Object	lookupVariable(java.lang.String name) Load the param information only when needed.

Methods inherited from class org.springframework.context.expression.MethodBasedEvaluationContext

lazyLoadArguments

Methods inherited from class org.springframework.expression.spel.support.StandardEvaluationContext

addConstructorResolver, addMethodResolver, addPropertyAccessor, getBeanResolver, getConstructorResolvers, getMethodResolvers, getOperatorOverloader, getPropertyAccessors, getRootObject, getTypeComparator, getTypeConverter, getTypeLocator, registerFunction, registerMethodFilter, removeConstructorResolver, removeMethodResolver, removePropertyAccessor, setBeanResolver, setConstructorResolvers, setMethodResolvers, setOperatorOverloader, setPropertyAccessors, setRootObject, setRootObject, setTypeComparator, setTypeConverter, setTypeLocator, setVariable, setVariables

Methods inherited from class java.lang.Object

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

Field Detail

unavailableVariables

private final java.util.List<java.lang.String> unavailableVariables

Constructor Detail

CacheEvaluationContext

CacheEvaluationContext(java.lang.Object rootObject,
                       java.lang.reflect.Method method,
                       java.lang.Object[] args,
                       ParameterNameDiscoverer paramDiscoverer)

Method Detail

addUnavailableVariable

public void addUnavailableVariable(java.lang.String name)

Add the specified variable name as unavailable for that context. Any expression trying to access this variable should lead to an exception.

This permits the validation of expressions that could potentially a variable even when such variable isn't available yet. Any expression trying to use that variable should therefore fail to evaluate.

lookupVariable

public java.lang.Object lookupVariable(java.lang.String name)

Load the param information only when needed.

Specified by:

lookupVariable in interface EvaluationContext

Overrides:

lookupVariable in class MethodBasedEvaluationContext

Parameters:

name - variable to lookup

Returns:

the value of the variable