SimpleEvaluationContext (spring-expression 5.0.15.BUILD-SNAPSHOT API)

java.lang.Object
- org.springframework.expression.spel.support.SimpleEvaluationContext

所有已实现的接口:

EvaluationContext
```
public class SimpleEvaluationContext
extends Object
implements EvaluationContext
```
A basic implementation of EvaluationContext that focuses on a subset of essential SpEL features and customization options, targeting simple condition evaluation and in particular data binding scenarios.
In many cases, the full extent of the SpEL language is not required and should be meaningfully restricted. Examples include but are not limited to data binding expressions, property-based filters, and others. To that effect, SimpleEvaluationContext is tailored to support only a subset of the SpEL language syntax, e.g. excluding references to Java types, constructors, and bean references.
When creating a SimpleEvaluationContext you need to choose the level of support that you need for property access in SpEL expressions:
- A custom PropertyAccessor (typically not reflection-based), potentially combined with a DataBindingPropertyAccessor
- Data binding properties for read-only access
- Data binding properties for read and write
Conveniently, forReadOnlyDataBinding() enables read access to properties via DataBindingPropertyAccessor; same for forReadWriteDataBinding() when write access is needed as well. Alternatively, configure custom accessors via forPropertyAccessors(org.springframework.expression.PropertyAccessor...), and potentially activate method resolution and/or a type converter through the builder.
Note that SimpleEvaluationContext is typically not configured with a default root object. Instead it is meant to be created once and used repeatedly through getValue calls on a pre-compiled Expression with both an EvaluationContext and a root object as arguments: Expression.getValue(EvaluationContext, Object).
For more power and flexibility, in particular for internal configuration scenarios, consider using StandardEvaluationContext instead.
从以下版本开始:

4.3.15

作者:

Rossen Stoyanchev, Juergen Hoeller

另请参阅:

forPropertyAccessors(org.springframework.expression.PropertyAccessor...), forReadOnlyDataBinding(), forReadWriteDataBinding(), StandardEvaluationContext, StandardTypeConverter, DataBindingPropertyAccessor

嵌套类概要

嵌套类
限定符和类型类和说明

static class SimpleEvaluationContext.Builder
Builder for SimpleEvaluationContext.

嵌套类
限定符和类型	类和说明
`static class`	`SimpleEvaluationContext.Builder` Builder for `SimpleEvaluationContext`.

方法概要

所有方法静态方法实例方法具体方法
限定符和类型	方法和说明
`static SimpleEvaluationContext.Builder`	`forPropertyAccessors(PropertyAccessor... accessors)` Create a `SimpleEvaluationContext` for the specified `PropertyAccessor` delegates: typically a custom `PropertyAccessor` specific to a use case (e.g. attribute resolution in a custom data structure), potentially combined with a `DataBindingPropertyAccessor` if property dereferences are needed as well.
`static SimpleEvaluationContext.Builder`	`forReadOnlyDataBinding()` Create a `SimpleEvaluationContext` for read-only access to public properties via `DataBindingPropertyAccessor`.
`static SimpleEvaluationContext.Builder`	`forReadWriteDataBinding()` Create a `SimpleEvaluationContext` for read-write access to public properties via `DataBindingPropertyAccessor`.
`BeanResolver`	`getBeanResolver()` `SimpleEvaluationContext` does not support the use of bean references.
`List<ConstructorResolver>`	`getConstructorResolvers()` Return an empty list, always, since this context does not support the use of type references.
`List<MethodResolver>`	`getMethodResolvers()` Return the specified `MethodResolver` delegates, if any.
`OperatorOverloader`	`getOperatorOverloader()` Return an instance of `StandardOperatorOverloader`.
`List<PropertyAccessor>`	`getPropertyAccessors()` Return the specified `PropertyAccessor` delegates, if any.
`TypedValue`	`getRootObject()` Return the specified root object, if any.
`TypeComparator`	`getTypeComparator()` Return an instance of `StandardTypeComparator`.
`TypeConverter`	`getTypeConverter()` The configured `TypeConverter`.
`TypeLocator`	`getTypeLocator()` `SimpleEvaluationContext` does not support use of type references.
`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.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 方法详细资料
  - getRootObject
```
public TypedValue getRootObject()
```
    Return the specified root object, if any.
    
    指定者:
    
    getRootObject 在接口中 EvaluationContext
  - getPropertyAccessors
```
public List<PropertyAccessor> getPropertyAccessors()
```
    Return the specified PropertyAccessor delegates, if any.
    
    指定者:
    
    getPropertyAccessors 在接口中 EvaluationContext
    
    另请参阅:
    
    forPropertyAccessors(org.springframework.expression.PropertyAccessor...)
  - getConstructorResolvers
```
public List<ConstructorResolver> getConstructorResolvers()
```
    Return an empty list, always, since this context does not support the use of type references.
    
    指定者:
    
    getConstructorResolvers 在接口中 EvaluationContext
  - getMethodResolvers
```
public List<MethodResolver> getMethodResolvers()
```
    Return the specified MethodResolver delegates, if any.
    
    指定者:
    
    getMethodResolvers 在接口中 EvaluationContext
    
    另请参阅:
    
    SimpleEvaluationContext.Builder.withMethodResolvers(org.springframework.expression.MethodResolver...)
  - getBeanResolver
```
@Nullable
public BeanResolver getBeanResolver()
```
    SimpleEvaluationContext does not support the use of bean references.
    
    指定者:
    
    getBeanResolver 在接口中 EvaluationContext
    
    返回:
    
    always null
  - getTypeLocator
```
public TypeLocator getTypeLocator()
```
    SimpleEvaluationContext does not support use of type references.
    
    指定者:
    
    getTypeLocator 在接口中 EvaluationContext
    
    返回:
    
    TypeLocator implementation that raises a SpelEvaluationException with SpelMessage.TYPE_NOT_FOUND.
  - getTypeConverter
```
public TypeConverter getTypeConverter()
```
    The configured TypeConverter.
    By default this is StandardTypeConverter.
    
    指定者:
    
    getTypeConverter 在接口中 EvaluationContext
    
    另请参阅:
    
    SimpleEvaluationContext.Builder.withTypeConverter(org.springframework.expression.TypeConverter), SimpleEvaluationContext.Builder.withConversionService(org.springframework.core.convert.ConversionService)
  - getTypeComparator
```
public TypeComparator getTypeComparator()
```
    Return an instance of StandardTypeComparator.
    
    指定者:
    
    getTypeComparator 在接口中 EvaluationContext
  - getOperatorOverloader
```
public OperatorOverloader getOperatorOverloader()
```
    Return an instance of StandardOperatorOverloader.
    
    指定者:
    
    getOperatorOverloader 在接口中 EvaluationContext
  - setVariable
```
public void setVariable(String name,
                        @Nullable
                        Object value)
```
    从接口复制的说明: EvaluationContext
    
    Set a named variable within this evaluation context to a specified value.
    
    指定者:
    
    setVariable 在接口中 EvaluationContext
    
    参数:
    
    name - variable to set
    
    value - value to be placed in the variable
  - lookupVariable
```
@Nullable
public Object lookupVariable(String name)
```
    从接口复制的说明: EvaluationContext
    
    Look up a named variable within this evaluation context.
    
    指定者:
    
    lookupVariable 在接口中 EvaluationContext
    
    参数:
    
    name - variable to lookup
    
    返回:
    
    the value of the variable, or null if not found
  - forPropertyAccessors
```
public static SimpleEvaluationContext.Builder forPropertyAccessors(PropertyAccessor... accessors)
```
    Create a SimpleEvaluationContext for the specified PropertyAccessor delegates: typically a custom PropertyAccessor specific to a use case (e.g. attribute resolution in a custom data structure), potentially combined with a DataBindingPropertyAccessor if property dereferences are needed as well.
    
    参数:
    
    accessors - the accessor delegates to use
    
    另请参阅:
    
    DataBindingPropertyAccessor.forReadOnlyAccess(), DataBindingPropertyAccessor.forReadWriteAccess()
  - forReadOnlyDataBinding
```
public static SimpleEvaluationContext.Builder forReadOnlyDataBinding()
```
    Create a SimpleEvaluationContext for read-only access to public properties via DataBindingPropertyAccessor.
    
    另请参阅:
    
    DataBindingPropertyAccessor.forReadOnlyAccess(), forPropertyAccessors(org.springframework.expression.PropertyAccessor...)
  - forReadWriteDataBinding
```
public static SimpleEvaluationContext.Builder forReadWriteDataBinding()
```
    Create a SimpleEvaluationContext for read-write access to public properties via DataBindingPropertyAccessor.
    
    另请参阅:
    
    DataBindingPropertyAccessor.forReadWriteAccess(), forPropertyAccessors(org.springframework.expression.PropertyAccessor...)

类 SimpleEvaluationContext

嵌套类概要

方法概要

从类继承的方法 java.lang.Object

方法详细资料

getRootObject

getPropertyAccessors

getConstructorResolvers

getMethodResolvers

getBeanResolver

getTypeLocator

getTypeConverter

getTypeComparator

getOperatorOverloader

setVariable

lookupVariable

forPropertyAccessors

forReadOnlyDataBinding

forReadWriteDataBinding