org.springframework.expression.spel.ast
Class PropertyOrFieldReference

java.lang.Object
  org.springframework.expression.spel.ast.SpelNodeImpl
      org.springframework.expression.spel.ast.PropertyOrFieldReference

All Implemented Interfaces:

SpelNode

public class PropertyOrFieldReference
extends SpelNodeImpl

Represents a simple property or field reference.

Since:

3.0

Author:

Andy Clement, Juergen Hoeller

Field Summary

private PropertyAccessor	cachedReadAccessor
private PropertyAccessor	cachedWriteAccessor
private java.lang.String	name
private boolean	nullSafe

Fields inherited from class org.springframework.expression.spel.ast.SpelNodeImpl

children, pos

Constructor Summary

PropertyOrFieldReference(boolean nullSafe, java.lang.String propertyOrFieldName, int pos)

Method Summary

java.lang.String	getName()
private java.util.List<PropertyAccessor>	getPropertyAccessorsToTry(java.lang.Class<?> targetType, ExpressionState state) Determines the set of property resolvers that should be used to try and access a property on the specified target type.
TypedValue	getValueInternal(ExpressionState state)
boolean	isNullSafe()
boolean	isWritable(ExpressionState state) Determine if this expression node will support a setValue() call.
boolean	isWritableProperty(java.lang.String name, ExpressionState state)
private TypedValue	readProperty(ExpressionState state, java.lang.String name) Attempt to read the named property from the current context object.
void	setValue(ExpressionState state, java.lang.Object newValue) Evaluate the expression to a node and then set the new value on that node.
java.lang.String	toStringAST()
private void	writeProperty(ExpressionState state, java.lang.String name, java.lang.Object newValue)

Methods inherited from class org.springframework.expression.spel.ast.SpelNodeImpl

getChild, getChildCount, getEndPosition, getObjectClass, getPreviousChild, getStartPosition, getTypedValue, getValue, getValue, nextChildIs

Methods inherited from class java.lang.Object

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

Field Detail

nullSafe

private final boolean nullSafe

name

private final java.lang.String name

cachedReadAccessor

private volatile PropertyAccessor cachedReadAccessor

cachedWriteAccessor

private volatile PropertyAccessor cachedWriteAccessor

Constructor Detail

PropertyOrFieldReference

public PropertyOrFieldReference(boolean nullSafe,
                                java.lang.String propertyOrFieldName,
                                int pos)

Method Detail

isNullSafe

public boolean isNullSafe()

getName

public java.lang.String getName()

getValueInternal

public TypedValue getValueInternal(ExpressionState state)
                            throws EvaluationException

Specified by:

getValueInternal in class SpelNodeImpl

Throws:

EvaluationException

setValue

public void setValue(ExpressionState state,
                     java.lang.Object newValue)
              throws SpelEvaluationException

Description copied from interface: SpelNode

Evaluate the expression to a node and then set the new value on that node. For example, if the expression evaluates to a property reference then the property will be set to the new value.

Specified by:

setValue in interface SpelNode

Overrides:

setValue in class SpelNodeImpl

Parameters:

state - the current expression state (includes the context)

newValue - the new value

Throws:

SpelEvaluationException

isWritable

public boolean isWritable(ExpressionState state)
                   throws SpelEvaluationException

Description copied from interface: SpelNode

Determine if this expression node will support a setValue() call.

Specified by:

isWritable in interface SpelNode

Overrides:

isWritable in class SpelNodeImpl

Parameters:

state - the current expression state (includes the context)

Returns:

true if the expression node will allow setValue()

Throws:

SpelEvaluationException

toStringAST

public java.lang.String toStringAST()

Specified by:

toStringAST in interface SpelNode

Specified by:

toStringAST in class SpelNodeImpl

Returns:

the string form of this AST node

readProperty

private TypedValue readProperty(ExpressionState state,
                                java.lang.String name)
                         throws EvaluationException

Attempt to read the named property from the current context object.

Parameters:

state - the evaluation state

name - the name of the property

Returns:

the value of the property

Throws:

SpelEvaluationException - if any problem accessing the property or it cannot be found

EvaluationException

writeProperty

private void writeProperty(ExpressionState state,
                           java.lang.String name,
                           java.lang.Object newValue)
                    throws SpelEvaluationException

Throws:

SpelEvaluationException

isWritableProperty

public boolean isWritableProperty(java.lang.String name,
                                  ExpressionState state)
                           throws SpelEvaluationException

Throws:

SpelEvaluationException

getPropertyAccessorsToTry

private java.util.List<PropertyAccessor> getPropertyAccessorsToTry(java.lang.Class<?> targetType,
                                                                   ExpressionState state)

Determines the set of property resolvers that should be used to try and access a property on the specified target type. The resolvers are considered to be in an ordered list, however in the returned list any that are exact matches for the input target type (as opposed to 'general' resolvers that could work for any type) are placed at the start of the list. In addition, there are specific resolvers that exactly name the class in question and resolvers that name a specific class but it is a supertype of the class we have. These are put at the end of the specific resolvers set and will be tried after exactly matching accessors but before generic accessors.

Parameters:

targetType - the type upon which property access is being attempted

Returns:

a list of resolvers that should be tried in order to access the property