org.springframework.expression.spel

Class ExpressionState

java.lang.Object

org.springframework.expression.spel.ExpressionState

public class ExpressionState
extends java.lang.Object

An ExpressionState is for maintaining per-expression-evaluation state, any changes to it are not seen by other expressions but it gives a place to hold local variables and for component expressions in a compound expression to communicate state. This is in contrast to the EvaluationContext, which is shared amongst expression evaluations, and any changes to it will be seen by other expressions or any code that chooses to ask questions of the context.

It also acts as a place for to define common utility routines that the various AST nodes might need.

Since:

3.0

Author:

Andy Clement

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	ExpressionState.VariableScope A new scope is entered when a function is called and it is used to hold the parameters to the function call.

Field Summary

Fields

Modifier and Type	Field and Description
private SpelParserConfiguration	configuration
private java.util.Stack<TypedValue>	contextObjects
private EvaluationContext	relatedContext
private TypedValue	rootObject
private java.util.Stack<TypedValue>	scopeRootObjects
private java.util.Stack<ExpressionState.VariableScope>	variableScopes

Constructor Summary

Constructors

Constructor and Description
ExpressionState(EvaluationContext context)
ExpressionState(EvaluationContext context, SpelParserConfiguration configuration)
ExpressionState(EvaluationContext context, TypedValue rootObject)
ExpressionState(EvaluationContext context, TypedValue rootObject, SpelParserConfiguration configuration)

Method Summary

Modifier and Type	Method and Description
java.lang.Object	convertValue(java.lang.Object value, TypeDescriptor targetTypeDescriptor)
java.lang.Object	convertValue(TypedValue value, TypeDescriptor targetTypeDescriptor)
private void	ensureVariableScopesInitialized()
void	enterScope()
void	enterScope(java.util.Map<java.lang.String,java.lang.Object> argMap)
void	enterScope(java.lang.String name, java.lang.Object value)
void	exitScope()
java.lang.Class<?>	findType(java.lang.String type)
TypedValue	getActiveContextObject() The active context object is what unqualified references to properties/etc are resolved against.
SpelParserConfiguration	getConfiguration()
EvaluationContext	getEvaluationContext()
java.util.List<PropertyAccessor>	getPropertyAccessors()
TypedValue	getRootContextObject()
TypedValue	getScopeRootContextObject()
TypeComparator	getTypeComparator()
TypeConverter	getTypeConverter()
java.lang.Object	lookupLocalVariable(java.lang.String name)
TypedValue	lookupVariable(java.lang.String name)
TypedValue	operate(Operation op, java.lang.Object left, java.lang.Object right)
void	popActiveContextObject()
void	pushActiveContextObject(TypedValue obj)
void	setLocalVariable(java.lang.String name, java.lang.Object value)
void	setVariable(java.lang.String name, java.lang.Object value)

Methods inherited from class java.lang.Object

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

Field Detail

relatedContext

private final EvaluationContext relatedContext

rootObject

private final TypedValue rootObject

scopeRootObjects

private java.util.Stack<TypedValue> scopeRootObjects

configuration

private final SpelParserConfiguration configuration

variableScopes

private java.util.Stack<ExpressionState.VariableScope> variableScopes

contextObjects

private java.util.Stack<TypedValue> contextObjects

Constructor Detail

ExpressionState

public ExpressionState(EvaluationContext context)

ExpressionState

public ExpressionState(EvaluationContext context,
                       SpelParserConfiguration configuration)

ExpressionState

public ExpressionState(EvaluationContext context,
                       TypedValue rootObject)

ExpressionState

public ExpressionState(EvaluationContext context,
                       TypedValue rootObject,
                       SpelParserConfiguration configuration)

Method Detail

ensureVariableScopesInitialized

private void ensureVariableScopesInitialized()

getActiveContextObject

public TypedValue getActiveContextObject()

The active context object is what unqualified references to properties/etc are resolved against.

pushActiveContextObject

public void pushActiveContextObject(TypedValue obj)

popActiveContextObject

public void popActiveContextObject()

getRootContextObject

public TypedValue getRootContextObject()

getScopeRootContextObject

public TypedValue getScopeRootContextObject()

setVariable

public void setVariable(java.lang.String name,
                        java.lang.Object value)

lookupVariable

public TypedValue lookupVariable(java.lang.String name)

getTypeComparator

public TypeComparator getTypeComparator()

findType

public java.lang.Class<?> findType(java.lang.String type)
                            throws EvaluationException

Throws:

EvaluationException

convertValue

public java.lang.Object convertValue(java.lang.Object value,
                                     TypeDescriptor targetTypeDescriptor)
                              throws EvaluationException

Throws:

EvaluationException

getTypeConverter

public TypeConverter getTypeConverter()

convertValue

public java.lang.Object convertValue(TypedValue value,
                                     TypeDescriptor targetTypeDescriptor)
                              throws EvaluationException

Throws:

EvaluationException

enterScope

public void enterScope(java.util.Map<java.lang.String,java.lang.Object> argMap)

enterScope

public void enterScope()

enterScope

public void enterScope(java.lang.String name,
                       java.lang.Object value)

exitScope

public void exitScope()

setLocalVariable

public void setLocalVariable(java.lang.String name,
                             java.lang.Object value)

lookupLocalVariable

public java.lang.Object lookupLocalVariable(java.lang.String name)

operate

public TypedValue operate(Operation op,
                          java.lang.Object left,
                          java.lang.Object right)
                   throws EvaluationException

Throws:

EvaluationException

getPropertyAccessors

public java.util.List<PropertyAccessor> getPropertyAccessors()

getEvaluationContext

public EvaluationContext getEvaluationContext()

getConfiguration

public SpelParserConfiguration getConfiguration()