org.springframework.expression

Interface EvaluationContext

All Known Implementing Classes:

MethodBasedEvaluationContext, SimpleEvaluationContext, StandardEvaluationContext

public interface EvaluationContext

Expressions are executed in an evaluation context. It is in this context that references are resolved when encountered during expression evaluation.

There is a default implementation of this EvaluationContext interface: StandardEvaluationContext which can be extended, rather than having to implement everything manually.

Since:

3.0

Author:

Andy Clement, Juergen Hoeller

Method Summary

Modifier and Type	Method and Description
BeanResolver	getBeanResolver() Return a bean resolver that can look up beans by name.
List<ConstructorResolver>	getConstructorResolvers() Return a list of resolvers that will be asked in turn to locate a constructor.
List<MethodResolver>	getMethodResolvers() Return a list of resolvers that will be asked in turn to locate a method.
OperatorOverloader	getOperatorOverloader() Return an operator overloader that may support mathematical operations between more than the standard set of types.
List<PropertyAccessor>	getPropertyAccessors() Return a list of accessors that will be asked in turn to read/write a property.
TypedValue	getRootObject() Return the default root context object against which unqualified properties/methods/etc should be resolved.
TypeComparator	getTypeComparator() Return a type comparator for comparing pairs of objects for equality.
TypeConverter	getTypeConverter() Return a type converter that can convert (or coerce) a value from one type to another.
TypeLocator	getTypeLocator() Return a type locator that can be used to find types, either by short or fully qualified name.
Object	lookupVariable(String name) Look up a named variable within this evaluation context.
void	setVariable(String name, Object value) Set a named variable within this evaluation context to a specified value.

Method Detail

getRootObject

TypedValue getRootObject()

Return the default root context object against which unqualified properties/methods/etc should be resolved. This can be overridden when evaluating an expression.

getPropertyAccessors

List<PropertyAccessor> getPropertyAccessors()

Return a list of accessors that will be asked in turn to read/write a property.

getConstructorResolvers

List<ConstructorResolver> getConstructorResolvers()

Return a list of resolvers that will be asked in turn to locate a constructor.

getMethodResolvers

List<MethodResolver> getMethodResolvers()

Return a list of resolvers that will be asked in turn to locate a method.

getBeanResolver

@Nullable
BeanResolver getBeanResolver()

Return a bean resolver that can look up beans by name.

getTypeLocator

TypeLocator getTypeLocator()

Return a type locator that can be used to find types, either by short or fully qualified name.

getTypeConverter

TypeConverter getTypeConverter()

Return a type converter that can convert (or coerce) a value from one type to another.

getTypeComparator

TypeComparator getTypeComparator()

Return a type comparator for comparing pairs of objects for equality.

getOperatorOverloader

OperatorOverloader getOperatorOverloader()

Return an operator overloader that may support mathematical operations between more than the standard set of types.

setVariable

void setVariable(String name,
                 @Nullable
                 Object value)

Set a named variable within this evaluation context to a specified value.

Parameters:

name - the name of the variable to set

value - the value to be placed in the variable

lookupVariable

@Nullable
Object lookupVariable(String name)

Look up a named variable within this evaluation context.

Parameters:

name - variable to lookup

Returns:

the value of the variable, or null if not found