程序包 cn.taketoday.expression.spel.support

类 StandardEvaluationContext

java.lang.Object

cn.taketoday.expression.spel.support.StandardEvaluationContext

所有已实现的接口:

EvaluationContext

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. Note, however, that you may need to manually configure a StandardTypeLocator with a specific ClassLoader to ensure that the SpEL expression parser is able to reliably locate user types. See setTypeLocator(TypeLocator) for details.

In addition to support for setting and looking up variables as defined in the EvaluationContext API, StandardEvaluationContext also provides support for registering and looking up functions. The registerFunction(...) methods provide a convenient way to register a function as a Method or a MethodHandle; however, a function can also be registered via setVariable(String, Object) or setVariables(Map). Since functions share a namespace with the variables in this evaluation context, care must be taken to ensure that function names and variable names do not overlap.

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.

从以下版本开始:

4.0

作者:

Andy Clement, Juergen Hoeller, Sam Brannen, Harry Yang

另请参阅:

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

字段概要

字段

修饰符和类型	字段	说明
private BeanResolver	beanResolver
private List<ConstructorResolver>	constructorResolvers
private List<MethodResolver>	methodResolvers
private OperatorOverloader	operatorOverloader
private List<PropertyAccessor>	propertyAccessors
private ReflectiveMethodResolver	reflectiveMethodResolver
private TypedValue	rootObject
private TypeComparator	typeComparator
private TypeConverter	typeConverter
private TypeLocator	typeLocator
private final ConcurrentHashMap<String,Object>	variables

构造器概要

构造器

限定符	构造器	说明
	StandardEvaluationContext()	Create a StandardEvaluationContext with a null root object.
protected	StandardEvaluationContext(StandardEvaluationContext shared)	Create a StandardEvaluationContext with the given root object.
	StandardEvaluationContext(Object rootObject)	Create a StandardEvaluationContext with the given root object.
protected	StandardEvaluationContext(Object rootObject, StandardEvaluationContext shared)	Create a StandardEvaluationContext with the given root object.

方法概要

修饰符和类型	方法	说明
private static <T> void	addBeforeDefault(List<T> resolvers, T resolver)
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()	Get the configured TypeLocator that will be used to find types, either by short or fully-qualified name.
private List<ConstructorResolver>	initConstructorResolvers()
private List<MethodResolver>	initMethodResolvers()
private List<PropertyAccessor>	initPropertyAccessors()
Object	lookupVariable(String name)	Look up a named variable or function within this evaluation context.
void	registerFunction(String name, MethodHandle methodHandle)	Register the specified MethodHandle as a SpEL function.
void	registerFunction(String name, Method method)	Register the specified Method as a SpEL function.
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)	Set the TypeLocator to use to find types, either by short or fully-qualified name.
void	setVariable(String name, Object value)	Set a named variable in this evaluation context to a specified value.
void	setVariables(Map<String,Object> variables)	Set multiple named variables in this evaluation context to the specified values.

从类继承的方法 java.lang.Object

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

从接口继承的方法 cn.taketoday.expression.EvaluationContext

assignVariable

字段详细资料

rootObject

private TypedValue rootObject

propertyAccessors

@Nullable
private volatile List<PropertyAccessor> propertyAccessors

constructorResolvers

@Nullable
private volatile List<ConstructorResolver> constructorResolvers

methodResolvers

@Nullable
private volatile List<MethodResolver> methodResolvers

reflectiveMethodResolver

@Nullable
private volatile ReflectiveMethodResolver reflectiveMethodResolver

beanResolver

@Nullable
private BeanResolver beanResolver

typeLocator

@Nullable
private TypeLocator typeLocator

typeConverter

@Nullable
private TypeConverter typeConverter

typeComparator

private TypeComparator typeComparator

operatorOverloader

private OperatorOverloader operatorOverloader

variables

private final ConcurrentHashMap<String,Object> variables

构造器详细资料

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.

参数:

rootObject - the root object to use

另请参阅:

• setRootObject(java.lang.Object, cn.taketoday.core.TypeDescriptor)

StandardEvaluationContext

protected StandardEvaluationContext(StandardEvaluationContext shared)

Create a StandardEvaluationContext with the given root object.

StandardEvaluationContext

protected StandardEvaluationContext(@Nullable
 Object rootObject,
 StandardEvaluationContext shared)

Create a StandardEvaluationContext with the given root object.

参数:

rootObject - the root object to use

另请参阅:

• setRootObject(java.lang.Object, cn.taketoday.core.TypeDescriptor)

方法详细资料

setRootObject

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

setRootObject

public void setRootObject(@Nullable
 Object rootObject)

getRootObject

public TypedValue getRootObject()

从接口复制的说明: EvaluationContext

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

指定者:

getRootObject 在接口中 EvaluationContext

setPropertyAccessors

public void setPropertyAccessors(List<PropertyAccessor> propertyAccessors)

getPropertyAccessors

public List<PropertyAccessor> getPropertyAccessors()

从接口复制的说明: EvaluationContext

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

指定者:

getPropertyAccessors 在接口中 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()

从接口复制的说明: EvaluationContext

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

指定者:

getConstructorResolvers 在接口中 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()

从接口复制的说明: EvaluationContext

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

指定者:

getMethodResolvers 在接口中 EvaluationContext

addMethodResolver

public void addMethodResolver(MethodResolver resolver)

removeMethodResolver

public boolean removeMethodResolver(MethodResolver methodResolver)

setBeanResolver

public void setBeanResolver(BeanResolver beanResolver)

getBeanResolver

@Nullable
public BeanResolver getBeanResolver()

从接口复制的说明: EvaluationContext

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

指定者:

getBeanResolver 在接口中 EvaluationContext

setTypeLocator

public void setTypeLocator(TypeLocator typeLocator)

Set the TypeLocator to use to find types, either by short or fully-qualified name.

By default, a StandardTypeLocator will be used.

NOTE: Even if a StandardTypeLocator is sufficient, you may need to manually configure a StandardTypeLocator with a specific ClassLoader to ensure that the SpEL expression parser is able to reliably locate user types.

参数:

typeLocator - the TypeLocator to use

另请参阅:

• StandardTypeLocator(ClassLoader)
• getTypeLocator()

getTypeLocator

public TypeLocator getTypeLocator()

Get the configured TypeLocator that will be used to find types, either by short or fully-qualified name.

See setTypeLocator(TypeLocator) for further details.

指定者:

getTypeLocator 在接口中 EvaluationContext

另请参阅:

• setTypeLocator(TypeLocator)

setTypeConverter

public void setTypeConverter(TypeConverter typeConverter)

getTypeConverter

public TypeConverter getTypeConverter()

从接口复制的说明: EvaluationContext

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

指定者:

getTypeConverter 在接口中 EvaluationContext

setTypeComparator

public void setTypeComparator(TypeComparator typeComparator)

getTypeComparator

public TypeComparator getTypeComparator()

从接口复制的说明: EvaluationContext

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

指定者:

getTypeComparator 在接口中 EvaluationContext

setOperatorOverloader

public void setOperatorOverloader(OperatorOverloader operatorOverloader)

getOperatorOverloader

public OperatorOverloader getOperatorOverloader()

从接口复制的说明: EvaluationContext

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

指定者:

getOperatorOverloader 在接口中 EvaluationContext

setVariable

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

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

If the specified name is null, it will be ignored. If the specified value is null, the named variable will be removed from this evaluation context.

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

Note that variables and functions share a common namespace in this evaluation context. See the class-level documentation for details.

指定者:

setVariable 在接口中 EvaluationContext

参数:

name - the name of the variable to set

value - the value to be placed in the variable

另请参阅:

• setVariables(Map)
• registerFunction(String, Method)
• registerFunction(String, MethodHandle)
• lookupVariable(String)

setVariables

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

Set multiple named variables in this evaluation context to the specified values.

This is a convenience variant of setVariable(String, Object).

Note that variables and functions share a common namespace in this evaluation context. See the class-level documentation for details.

参数:

variables - the names and values of the variables to set

另请参阅:

• setVariable(String, Object)

registerFunction

public void registerFunction(String name,
 Method method)

Register the specified Method as a SpEL function.

Note that variables and functions share a common namespace in this evaluation context. See the class-level documentation for details.

参数:

name - the name of the function

method - the Method to register

另请参阅:

• registerFunction(String, MethodHandle)

registerFunction

public void registerFunction(String name,
 MethodHandle methodHandle)

Register the specified MethodHandle as a SpEL function.

Note that variables and functions share a common namespace in this evaluation context. See the class-level documentation for details.

参数:

name - the name of the function

methodHandle - the MethodHandle to register

另请参阅:

• registerFunction(String, Method)

lookupVariable

@Nullable
public Object lookupVariable(String name)

Look up a named variable or function within this evaluation context.

Note that variables and functions share a common namespace in this evaluation context. See the class-level documentation for details.

指定者:

lookupVariable 在接口中 EvaluationContext

参数:

name - the name of the variable or function to look up

返回:

the value of the variable or function, 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.

参数:

type - the type for which the filter should be called

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

抛出:

IllegalStateException - if the ReflectiveMethodResolver is not in use

initPropertyAccessors

private List<PropertyAccessor> initPropertyAccessors()

initConstructorResolvers

private List<ConstructorResolver> initConstructorResolvers()

initMethodResolvers

private List<MethodResolver> initMethodResolvers()

addBeforeDefault

private static <T> void addBeforeDefault(List<T> resolvers,
 T resolver)