org.springframework.expression
Interface EvaluationContext

All Known Implementing Classes:
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 the EvaluationContext, StandardEvaluationContext that can be extended, rather than having to implement everything.

Since:
3.0
Author:
Andy Clement, Juergen Hoeller

Method Summary
 List<ConstructorResolver> getConstructorResolvers()
           
 List<MethodResolver> getMethodResolvers()
           
 OperatorOverloader getOperatorOverloader()
           
 List<PropertyAccessor> getPropertyAccessors()
           
 TypedValue getRootObject()
           
 TypeComparator getTypeComparator()
           
 TypeConverter getTypeConverter()
           
 TypeLocator getTypeLocator()
           
 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()
Returns:
the default root context object against which unqualified properties/methods/etc should be resolved. This can be overridden when evaluating an expression.

getConstructorResolvers

List<ConstructorResolver> getConstructorResolvers()
Returns:
a list of resolvers that will be asked in turn to locate a constructor

getMethodResolvers

List<MethodResolver> getMethodResolvers()
Returns:
a list of resolvers that will be asked in turn to locate a method

getPropertyAccessors

List<PropertyAccessor> getPropertyAccessors()
Returns:
a list of accessors that will be asked in turn to read/write a property

getTypeLocator

TypeLocator getTypeLocator()
Returns:
a type locator that can be used to find types, either by short or fully qualified name.

getTypeConverter

TypeConverter getTypeConverter()
Returns:
a type converter that can convert (or coerce) a value from one type to another.

getTypeComparator

TypeComparator getTypeComparator()
Returns:
a type comparator for comparing pairs of objects for equality.

getOperatorOverloader

OperatorOverloader getOperatorOverloader()
Returns:
an operator overloader that may support mathematical operations between more than the standard set of types

setVariable

void setVariable(String name,
                 Object value)
Set a named variable within this evaluation context to a specified value.

Parameters:
name - variable to set
value - value to be placed in the variable

lookupVariable

Object lookupVariable(String name)
Look up a named variable within this evaluation context.

Parameters:
name - variable to lookup
Returns:
the value of the variable