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, SimpleEvaluationContext#forReadOnlyDataBinding() enables read access to properties via DataBindingPropertyAccessor; same for SimpleEvaluationContext#forReadWriteDataBinding() when write access is needed as well. Alternatively, configure custom accessors via SimpleEvaluationContext#forPropertyAccessors, 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 org.springframework.expression.Expression with both an EvaluationContext and a root object as arguments: org.springframework.expression.Expression#getValue(EvaluationContext, Object).

In addition to support for setting and looking up variables as defined in the EvaluationContext API, SimpleEvaluationContext also provides support for registering and looking up functions as variables. Since functions share a common namespace with the variables in this evaluation context, care must be taken to ensure that function names and variable names do not overlap.

For more power and flexibility, in particular for internal configuration scenarios, consider using StandardEvaluationContext instead.

Nested and Inner Type Summary

Modifier and Type	Class and Description
public static class	SimpleEvaluationContext.Builder Builder for `SimpleEvaluationContext`.

Modifier and Type	Field and Description
private final List<MethodResolver>	methodResolvers
private final OperatorOverloader	operatorOverloader
private final List<PropertyAccessor>	propertyAccessors
private final TypedValue	rootObject
private final TypeComparator	typeComparator
private final TypeConverter	typeConverter
private static final TypeLocator	typeNotFoundTypeLocator
private final Map<String, Object>	variables

Access	Constructor and Description
private	SimpleEvaluationContext(List<PropertyAccessor> accessors, List<MethodResolver> resolvers, TypeConverter converter, TypedValue rootObject)

Method Summary

Modifier and Type	Method and Description
public TypedValue	assignVariable(String the name of the variable to assign name, Supplier<TypedValue> the supplier of the value to be assigned to the variable valueSupplier) Overrides default org.springframework.expression.EvaluationContext.assignVariable. `SimpleEvaluationContext` does not support variable assignment within expressions.
public static SimpleEvaluationContext.Builder	forPropertyAccessors(PropertyAccessor... the accessor delegates to use 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.
public static SimpleEvaluationContext.Builder	forReadOnlyDataBinding() Create a `SimpleEvaluationContext` for read-only access to public properties via `DataBindingPropertyAccessor`.
public static SimpleEvaluationContext.Builder	forReadWriteDataBinding() Create a `SimpleEvaluationContext` for read-write access to public properties via `DataBindingPropertyAccessor`.
public BeanResolver	Returns: always `null` getBeanResolver() Implements org.springframework.expression.EvaluationContext.getBeanResolver. `SimpleEvaluationContext` does not support the use of bean references.
public List<ConstructorResolver>	getConstructorResolvers() Implements org.springframework.expression.EvaluationContext.getConstructorResolvers. Return an empty list, always, since this context does not support the use of type references.
public List<MethodResolver>	getMethodResolvers() Implements org.springframework.expression.EvaluationContext.getMethodResolvers. Return the specified `MethodResolver` delegates, if any.
public OperatorOverloader	getOperatorOverloader() Implements org.springframework.expression.EvaluationContext.getOperatorOverloader. Return an instance of `StandardOperatorOverloader`.
public List<PropertyAccessor>	getPropertyAccessors() Implements org.springframework.expression.EvaluationContext.getPropertyAccessors. Return the specified `PropertyAccessor` delegates, if any.
public TypedValue	getRootObject() Implements org.springframework.expression.EvaluationContext.getRootObject. Return the specified root object, if any.
public TypeComparator	getTypeComparator() Implements org.springframework.expression.EvaluationContext.getTypeComparator. Return an instance of `StandardTypeComparator`.
public TypeConverter	getTypeConverter() Implements org.springframework.expression.EvaluationContext.getTypeConverter. The configured `TypeConverter`.
public TypeLocator	Returns: `TypeLocator` implementation that raises a `SpelEvaluationException` with `SpelMessage#TYPE_NOT_FOUND` getTypeLocator() Implements org.springframework.expression.EvaluationContext.getTypeLocator. `SimpleEvaluationContext` does not support use of type references.
public Object	Returns: the value of the variable or function, or `null` if not found lookupVariable(String the name of the variable or function to look up name) Implements org.springframework.expression.EvaluationContext.lookupVariable. Look up a named variable or function within this evaluation context.
public void	setVariable(String the name of the variable or function to set name, Object the value to be placed in the variable or function value) Implements org.springframework.expression.EvaluationContext.setVariable. Set a named variable or function in this evaluation context to the specified value.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

methodResolvers	back to summary
private final List<MethodResolver> methodResolvers

operatorOverloader	back to summary
private final OperatorOverloader operatorOverloader

propertyAccessors	back to summary
private final List<PropertyAccessor> propertyAccessors

rootObject	back to summary
private final TypedValue rootObject

typeComparator	back to summary
private final TypeComparator typeComparator

typeConverter	back to summary
private final TypeConverter typeConverter

typeNotFoundTypeLocator	back to summary
private static final TypeLocator typeNotFoundTypeLocator

variables	back to summary
private final Map<String, Object> variables

Constructor Detail

SimpleEvaluationContext	back to summary
private SimpleEvaluationContext(List<PropertyAccessor> accessors, List<MethodResolver> resolvers, TypeConverter converter, TypedValue rootObject)

Method Detail

assignVariable back to summary

assignVariable	back to summary
public TypedValue assignVariable(String name, Supplier<TypedValue> valueSupplier) Overrides default org.springframework.expression.EvaluationContext.assignVariable. `SimpleEvaluationContext` does not support variable assignment within expressions. Parameters name:String Doc from org.springframework.expression.EvaluationContext.assignVariable. the name of the variable to assign valueSupplier:Supplier<TypedValue> Doc from org.springframework.expression.EvaluationContext.assignVariable. the supplier of the value to be assigned to the variable Returns:TypedValue Doc from org.springframework.expression.EvaluationContext.assignVariable. a `TypedValue` wrapping the assigned value Annotations @Override Exceptions SpelEvaluationException: with `SpelMessage#VARIABLE_ASSIGNMENT_NOT_SUPPORTED` Since 5.2.24

public TypedValue assignVariable(String name, Supplier<TypedValue> valueSupplier)

Overrides default org.springframework.expression.EvaluationContext.assignVariable.

SimpleEvaluationContext does not support variable assignment within expressions.

Parameters

name:String

Doc from org.springframework.expression.EvaluationContext.assignVariable.

the name of the variable to assign

valueSupplier:Supplier<TypedValue>

Doc from org.springframework.expression.EvaluationContext.assignVariable.

the supplier of the value to be assigned to the variable

Returns:TypedValue

Doc from org.springframework.expression.EvaluationContext.assignVariable.

a TypedValue wrapping the assigned value

Annotations

@Override

Exceptions

SpelEvaluationException:: with SpelMessage#VARIABLE_ASSIGNMENT_NOT_SUPPORTED

Since

5.2.24

forPropertyAccessors back to summary

forPropertyAccessors	back to summary
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. Parameters accessors:PropertyAccessor[] the accessor delegates to use See Also `DataBindingPropertyAccessor#forReadOnlyAccess()`, `DataBindingPropertyAccessor#forReadWriteAccess()`

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.

Parameters

accessors:PropertyAccessor[]: the accessor delegates to use

forReadOnlyDataBinding back to summary

forReadOnlyDataBinding	back to summary
public static SimpleEvaluationContext.Builder forReadOnlyDataBinding() Create a `SimpleEvaluationContext` for read-only access to public properties via `DataBindingPropertyAccessor`. See Also `DataBindingPropertyAccessor#forReadOnlyAccess()`, `forPropertyAccessors`

public static SimpleEvaluationContext.Builder forReadOnlyDataBinding()

Create a SimpleEvaluationContext for read-only access to public properties via DataBindingPropertyAccessor.

See Also: DataBindingPropertyAccessor#forReadOnlyAccess(), forPropertyAccessors

forReadWriteDataBinding back to summary

forReadWriteDataBinding	back to summary
public static SimpleEvaluationContext.Builder forReadWriteDataBinding() Create a `SimpleEvaluationContext` for read-write access to public properties via `DataBindingPropertyAccessor`. See Also `DataBindingPropertyAccessor#forReadWriteAccess()`, `forPropertyAccessors`

public static SimpleEvaluationContext.Builder forReadWriteDataBinding()

Create a SimpleEvaluationContext for read-write access to public properties via DataBindingPropertyAccessor.

See Also: DataBindingPropertyAccessor#forReadWriteAccess(), forPropertyAccessors

getBeanResolver back to summary

getBeanResolver	back to summary
public BeanResolver getBeanResolver() Implements org.springframework.expression.EvaluationContext.getBeanResolver. `SimpleEvaluationContext` does not support the use of bean references. Returns:BeanResolver always `null` Annotations @Override @Nullable

public BeanResolver getBeanResolver()

Implements org.springframework.expression.EvaluationContext.getBeanResolver.

SimpleEvaluationContext does not support the use of bean references.

Returns:BeanResolver

always null

Annotations

@Override
@Nullable

getConstructorResolvers	back to summary
public List<ConstructorResolver> getConstructorResolvers() Implements org.springframework.expression.EvaluationContext.getConstructorResolvers. Return an empty list, always, since this context does not support the use of type references. Annotations @Override

getConstructorResolvers

back to summary

public List<ConstructorResolver> getConstructorResolvers()

Implements org.springframework.expression.EvaluationContext.getConstructorResolvers.

Return an empty list, always, since this context does not support the use of type references.

Annotations

@Override

getMethodResolvers back to summary

getMethodResolvers	back to summary
public List<MethodResolver> getMethodResolvers() Implements org.springframework.expression.EvaluationContext.getMethodResolvers. Return the specified `MethodResolver` delegates, if any. Annotations @Override See Also `Builder#withMethodResolvers`

public List<MethodResolver> getMethodResolvers()

Implements org.springframework.expression.EvaluationContext.getMethodResolvers.

Return the specified MethodResolver delegates, if any.

Annotations

@Override

See Also

Builder#withMethodResolvers

getOperatorOverloader back to summary

getOperatorOverloader	back to summary
public OperatorOverloader getOperatorOverloader() Implements org.springframework.expression.EvaluationContext.getOperatorOverloader. Return an instance of `StandardOperatorOverloader`. Annotations @Override

public OperatorOverloader getOperatorOverloader()

Implements org.springframework.expression.EvaluationContext.getOperatorOverloader.

Return an instance of StandardOperatorOverloader.

Annotations

@Override

getPropertyAccessors back to summary

getPropertyAccessors	back to summary
public List<PropertyAccessor> getPropertyAccessors() Implements org.springframework.expression.EvaluationContext.getPropertyAccessors. Return the specified `PropertyAccessor` delegates, if any. Annotations @Override See Also `forPropertyAccessors`

public List<PropertyAccessor> getPropertyAccessors()

Implements org.springframework.expression.EvaluationContext.getPropertyAccessors.

Return the specified PropertyAccessor delegates, if any.

Annotations

@Override

See Also

forPropertyAccessors

getRootObject	back to summary
public TypedValue getRootObject() Implements org.springframework.expression.EvaluationContext.getRootObject. Return the specified root object, if any. Annotations @Override

getRootObject

back to summary

public TypedValue getRootObject()

Implements org.springframework.expression.EvaluationContext.getRootObject.

Return the specified root object, if any.

Annotations

@Override

getTypeComparator back to summary

getTypeComparator	back to summary
public TypeComparator getTypeComparator() Implements org.springframework.expression.EvaluationContext.getTypeComparator. Return an instance of `StandardTypeComparator`. Annotations @Override

public TypeComparator getTypeComparator()

Implements org.springframework.expression.EvaluationContext.getTypeComparator.

Return an instance of StandardTypeComparator.

Annotations

@Override

getTypeConverter back to summary

getTypeConverter	back to summary
public TypeConverter getTypeConverter() Implements org.springframework.expression.EvaluationContext.getTypeConverter. The configured `TypeConverter`. By default this is `StandardTypeConverter`. Annotations @Override See Also `Builder#withTypeConverter`, `Builder#withConversionService`

public TypeConverter getTypeConverter()

Implements org.springframework.expression.EvaluationContext.getTypeConverter.

The configured TypeConverter.

By default this is StandardTypeConverter.

Annotations

@Override

getTypeLocator back to summary

getTypeLocator	back to summary
public TypeLocator getTypeLocator() Implements org.springframework.expression.EvaluationContext.getTypeLocator. `SimpleEvaluationContext` does not support use of type references. Returns:TypeLocator `TypeLocator` implementation that raises a `SpelEvaluationException` with `SpelMessage#TYPE_NOT_FOUND` Annotations @Override

public TypeLocator getTypeLocator()

Implements org.springframework.expression.EvaluationContext.getTypeLocator.

SimpleEvaluationContext does not support use of type references.

Returns:TypeLocator

TypeLocator implementation that raises a SpelEvaluationException with SpelMessage#TYPE_NOT_FOUND

Annotations

@Override

lookupVariable back to summary

lookupVariable	back to summary
public Object lookupVariable(String name) Implements org.springframework.expression.EvaluationContext.lookupVariable. 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. Parameters name:String the name of the variable or function to look up Returns:Object the value of the variable or function, or `null` if not found Annotations @Override @Nullable

public Object lookupVariable(String name)

Implements org.springframework.expression.EvaluationContext.lookupVariable.

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.

Parameters

name:String: the name of the variable or function to look up

Returns:Object

the value of the variable or function, or null if not found

Annotations

@Override
@Nullable

setVariable back to summary

setVariable	back to summary
public void setVariable(String name, Object value) Implements org.springframework.expression.EvaluationContext.setVariable. Set a named variable or function in this evaluation context to the specified value. A function can be registered as a `java.lang.reflect.Method` or a `java.lang.invoke.MethodHandle`. Note that variables and functions share a common namespace in this evaluation context. See the class-level documentation for details. Parameters name:String the name of the variable or function to set value:Object the value to be placed in the variable or function Annotations @Override See Also `lookupVariable(String)`

public void setVariable(String name, Object value)

Implements org.springframework.expression.EvaluationContext.setVariable.

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

A function can be registered as a java.lang.reflect.Method or a java.lang.invoke.MethodHandle.

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

Parameters

name:String: the name of the variable or function to set
value:Object: the value to be placed in the variable or function

Annotations

@Override

See Also

lookupVariable(String)

org.springframework.expression.spel.support back to summary

public final Class SimpleEvaluationContext.Builder

Class Inheritance

extends Object

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

Builder for SimpleEvaluationContext.

Field Summary

Modifier and Type	Field and Description
private final List<PropertyAccessor>	accessors
private List<MethodResolver>	resolvers
private TypedValue	rootObject
private TypeConverter	typeConverter

Constructor Summary

Access	Constructor and Description
private	Builder(PropertyAccessor... accessors)

Method Summary

Modifier and Type	Method and Description
public SimpleEvaluationContext	build()
public SimpleEvaluationContext.Builder	withConversionService(ConversionService conversionService) Register a custom `ConversionService`.
public SimpleEvaluationContext.Builder	withInstanceMethods() Register a `DataBindingMethodResolver` for instance method invocation purposes (i.e. not supporting static methods) in addition to the specified property accessors, typically in combination with a `DataBindingPropertyAccessor`.
public SimpleEvaluationContext.Builder	withMethodResolvers(MethodResolver... the resolver delegates to use resolvers) Register the specified `MethodResolver` delegates for a combination of property access and method resolution.
public SimpleEvaluationContext.Builder	withRootObject(Object rootObject) Specify a default root object to resolve against.
public SimpleEvaluationContext.Builder	withTypeConverter(TypeConverter converter) Register a custom `TypeConverter`.
public SimpleEvaluationContext.Builder	withTypedRootObject(Object rootObject, TypeDescriptor typeDescriptor) Specify a typed root object to resolve against.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

accessors	back to summary
private final List<PropertyAccessor> accessors

resolvers	back to summary
private List<MethodResolver> resolvers

rootObject	back to summary
private TypedValue rootObject Annotations @Nullable

typeConverter	back to summary
private TypeConverter typeConverter Annotations @Nullable

Constructor Detail

Builder	back to summary
private Builder(PropertyAccessor... accessors)

Method Detail

build	back to summary
public SimpleEvaluationContext build()

withConversionService back to summary

withConversionService	back to summary
public SimpleEvaluationContext.Builder withConversionService(ConversionService conversionService) Register a custom `ConversionService`. By default a `StandardTypeConverter` backed by a `org.springframework.core.convert.support.DefaultConversionService` is used. See Also `withTypeConverter`, `StandardTypeConverter#StandardTypeConverter(ConversionService)`

public SimpleEvaluationContext.Builder withConversionService(ConversionService conversionService)

By default a StandardTypeConverter backed by a org.springframework.core.convert.support.DefaultConversionService is used.

See Also: withTypeConverter, StandardTypeConverter#StandardTypeConverter(ConversionService)

withInstanceMethods back to summary

withInstanceMethods	back to summary
public SimpleEvaluationContext.Builder withInstanceMethods() Register a `DataBindingMethodResolver` for instance method invocation purposes (i.e. not supporting static methods) in addition to the specified property accessors, typically in combination with a `DataBindingPropertyAccessor`. See Also `withMethodResolvers`, `SimpleEvaluationContext#forReadOnlyDataBinding()`, `SimpleEvaluationContext#forReadWriteDataBinding()`

public SimpleEvaluationContext.Builder withInstanceMethods()

Register a DataBindingMethodResolver for instance method invocation purposes (i.e. not supporting static methods) in addition to the specified property accessors, typically in combination with a DataBindingPropertyAccessor.

See Also: withMethodResolvers, SimpleEvaluationContext#forReadOnlyDataBinding(), SimpleEvaluationContext#forReadWriteDataBinding()

withMethodResolvers back to summary

withMethodResolvers	back to summary
public SimpleEvaluationContext.Builder withMethodResolvers(MethodResolver... resolvers) Register the specified `MethodResolver` delegates for a combination of property access and method resolution. Parameters resolvers:MethodResolver[] the resolver delegates to use See Also `withInstanceMethods()`, `SimpleEvaluationContext#forPropertyAccessors`

public SimpleEvaluationContext.Builder withMethodResolvers(MethodResolver... resolvers)

Parameters

resolvers:MethodResolver[]: the resolver delegates to use

withRootObject back to summary

withRootObject	back to summary
public SimpleEvaluationContext.Builder withRootObject(Object rootObject) Specify a default root object to resolve against. Default is none, expecting an object argument at evaluation time. See Also `org.springframework.expression.Expression#getValue(EvaluationContext)`, `org.springframework.expression.Expression#getValue(EvaluationContext, Object)`

public SimpleEvaluationContext.Builder withRootObject(Object rootObject)

Specify a default root object to resolve against.

Default is none, expecting an object argument at evaluation time.

See Also: org.springframework.expression.Expression#getValue(EvaluationContext), org.springframework.expression.Expression#getValue(EvaluationContext, Object)

withTypeConverter back to summary

withTypeConverter	back to summary
public SimpleEvaluationContext.Builder withTypeConverter(TypeConverter converter) Register a custom `TypeConverter`. By default a `StandardTypeConverter` backed by a `org.springframework.core.convert.support.DefaultConversionService` is used. See Also `withConversionService`, `StandardTypeConverter#StandardTypeConverter()`

public SimpleEvaluationContext.Builder withTypeConverter(TypeConverter converter)

By default a StandardTypeConverter backed by a org.springframework.core.convert.support.DefaultConversionService is used.

See Also: withConversionService, StandardTypeConverter#StandardTypeConverter()

withTypedRootObject back to summary

withTypedRootObject	back to summary
public SimpleEvaluationContext.Builder withTypedRootObject(Object rootObject, TypeDescriptor typeDescriptor) Specify a typed root object to resolve against. Default is none, expecting an object argument at evaluation time. See Also `org.springframework.expression.Expression#getValue(EvaluationContext)`, `org.springframework.expression.Expression#getValue(EvaluationContext, Object)`

public SimpleEvaluationContext.Builder withTypedRootObject(Object rootObject, TypeDescriptor typeDescriptor)

Specify a typed root object to resolve against.

Default is none, expecting an object argument at evaluation time.

See Also: org.springframework.expression.Expression#getValue(EvaluationContext), org.springframework.expression.Expression#getValue(EvaluationContext, Object)