org.springframework.expression.spel.support

Class StandardEvaluationContext

java.lang.Object

org.springframework.expression.spel.support.StandardEvaluationContext

All Implemented Interfaces:

EvaluationContext

Direct Known Subclasses:

MethodBasedEvaluationContext

public class StandardEvaluationContext
extends Object
implements EvaluationContext

A powerful and highly configurable EvaluationContext implementation. This context uses standard implementations of all applicable strategies, based on reflection to resolve properties, methods and fields.

For a simpler builder-style context variant for data-binding purposes, consider using SimpleEvaluationContext instead which allows for opting into several SpEL features as needed by specific evaluation cases.

Since:

3.0

Author:

Andy Clement, Juergen Hoeller, Sam Brannen

See Also:

SimpleEvaluationContext, ReflectivePropertyAccessor, ReflectiveConstructorResolver, ReflectiveMethodResolver, StandardTypeLocator, StandardTypeConverter, StandardTypeComparator, StandardOperatorOverloader

Constructor Summary

Constructors

Constructor and Description
StandardEvaluationContext() Create a StandardEvaluationContext with a null root object.
StandardEvaluationContext(Object rootObject) Create a StandardEvaluationContext with the given root object.

Method Summary

Modifier and Type	Method and Description
void	addConstructorResolver(ConstructorResolver resolver)
void	addMethodResolver(MethodResolver resolver)
void	addPropertyAccessor(PropertyAccessor accessor)
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	registerFunction(String name, Method method)
void	registerMethodFilter(Class<?> type, MethodFilter filter) Register a MethodFilter which will be called during method resolution for the specified type.
boolean	removeConstructorResolver(ConstructorResolver resolver)
boolean	removeMethodResolver(MethodResolver methodResolver)
boolean	removePropertyAccessor(PropertyAccessor accessor)
void	setBeanResolver(BeanResolver beanResolver)
void	setConstructorResolvers(List<ConstructorResolver> constructorResolvers)
void	setMethodResolvers(List<MethodResolver> methodResolvers)
void	setOperatorOverloader(OperatorOverloader operatorOverloader)
void	setPropertyAccessors(List<PropertyAccessor> propertyAccessors)
void	setRootObject(Object rootObject)
void	setRootObject(Object rootObject, TypeDescriptor typeDescriptor)
void	setTypeComparator(TypeComparator typeComparator)
void	setTypeConverter(TypeConverter typeConverter)
void	setTypeLocator(TypeLocator typeLocator)
void	setVariable(String name, Object value) Set a named variable in this evaluation context to a specified value.
void	setVariables(Map<String,Object> variables)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.expression.EvaluationContext

assignVariable, isAssignmentEnabled

Constructor Detail

StandardEvaluationContext

public StandardEvaluationContext()

Create a StandardEvaluationContext with a null root object.

StandardEvaluationContext

public StandardEvaluationContext(@Nullable
                                 Object rootObject)

Create a StandardEvaluationContext with the given root object.

Parameters:

rootObject - the root object to use

See Also:

setRootObject(java.lang.Object, org.springframework.core.convert.TypeDescriptor)

Method Detail

setRootObject

public void setRootObject(@Nullable
                          Object rootObject,
                          TypeDescriptor typeDescriptor)

setRootObject

public void setRootObject(@Nullable
                          Object rootObject)

getRootObject

public TypedValue getRootObject()

Description copied from interface: EvaluationContext

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

Specified by:

getRootObject in interface EvaluationContext

setPropertyAccessors

public void setPropertyAccessors(List<PropertyAccessor> propertyAccessors)

getPropertyAccessors

public List<PropertyAccessor> getPropertyAccessors()

Description copied from interface: EvaluationContext

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

Specified by:

getPropertyAccessors in interface EvaluationContext

addPropertyAccessor

public void addPropertyAccessor(PropertyAccessor accessor)

removePropertyAccessor

public boolean removePropertyAccessor(PropertyAccessor accessor)

setConstructorResolvers

public void setConstructorResolvers(List<ConstructorResolver> constructorResolvers)

getConstructorResolvers

public List<ConstructorResolver> getConstructorResolvers()

Description copied from interface: EvaluationContext

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

Specified by:

getConstructorResolvers in interface EvaluationContext

addConstructorResolver

public void addConstructorResolver(ConstructorResolver resolver)

removeConstructorResolver

public boolean removeConstructorResolver(ConstructorResolver resolver)

setMethodResolvers

public void setMethodResolvers(List<MethodResolver> methodResolvers)

getMethodResolvers

public List<MethodResolver> getMethodResolvers()

Description copied from interface: EvaluationContext

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

Specified by:

getMethodResolvers in interface EvaluationContext

addMethodResolver

public void addMethodResolver(MethodResolver resolver)

removeMethodResolver

public boolean removeMethodResolver(MethodResolver methodResolver)

setBeanResolver

public void setBeanResolver(BeanResolver beanResolver)

getBeanResolver

@Nullable
public BeanResolver getBeanResolver()

Description copied from interface: EvaluationContext

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

Specified by:

getBeanResolver in interface EvaluationContext

setTypeLocator

public void setTypeLocator(TypeLocator typeLocator)

getTypeLocator

public TypeLocator getTypeLocator()

Description copied from interface: EvaluationContext

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

Specified by:

getTypeLocator in interface EvaluationContext

setTypeConverter

public void setTypeConverter(TypeConverter typeConverter)

getTypeConverter

public TypeConverter getTypeConverter()

Description copied from interface: EvaluationContext

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

Specified by:

getTypeConverter in interface EvaluationContext

setTypeComparator

public void setTypeComparator(TypeComparator typeComparator)

getTypeComparator

public TypeComparator getTypeComparator()

Description copied from interface: EvaluationContext

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

Specified by:

getTypeComparator in interface EvaluationContext

setOperatorOverloader

public void setOperatorOverloader(OperatorOverloader operatorOverloader)

getOperatorOverloader

public OperatorOverloader getOperatorOverloader()

Description copied from interface: EvaluationContext

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

Specified by:

getOperatorOverloader in interface EvaluationContext

setVariable

public void setVariable(@Nullable
                        String name,
                        @Nullable
                        Object value)

Description copied from interface: EvaluationContext

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

In contrast to EvaluationContext.assignVariable(String, Supplier), this method should only be invoked programmatically when interacting directly with the EvaluationContext — for example, to provide initial configuration for the context.

Specified by:

setVariable in interface EvaluationContext

Parameters:

name - the name of the variable to set

value - the value to be placed in the variable

setVariables

public void setVariables(Map<String,Object> variables)

registerFunction

public void registerFunction(String name,
                             Method method)

lookupVariable

@Nullable
public Object lookupVariable(String name)

Description copied from interface: EvaluationContext

Look up a named variable within this evaluation context.

Specified by:

lookupVariable in interface EvaluationContext

Parameters:

name - the name of the variable to look up

Returns:

the value of the variable, or null if not found

registerMethodFilter

public void registerMethodFilter(Class<?> type,
                                 MethodFilter filter)
                          throws IllegalStateException

Register a MethodFilter which will be called during method resolution for the specified type.

The MethodFilter may remove methods and/or sort the methods which will then be used by SpEL as the candidates to look through for a match.

Parameters:

type - the type for which the filter should be called

filter - a MethodFilter, or null to unregister a filter for the type

Throws:

IllegalStateException - if the ReflectiveMethodResolver is not in use