org.springframework.expression.spel.ast
Class Indexer

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

All Implemented Interfaces:

SpelNode

public class Indexer
extends SpelNodeImpl

An Indexer can index into some proceeding structure to access a particular piece of it. Supported structures are: strings/collections (lists/sets)/arrays

Since:

3.0

Author:

Andy Clement

Field Summary

private PropertyAccessor	cachedReadAccessor
private java.lang.String	cachedReadName
private java.lang.Class<?>	cachedReadTargetType
private PropertyAccessor	cachedWriteAccessor
private java.lang.String	cachedWriteName
private java.lang.Class<?>	cachedWriteTargetType

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

children, pos

Constructor Summary

Indexer(int pos, SpelNodeImpl expr)

Method Summary

private java.lang.Object	accessArrayElement(java.lang.Object ctx, int idx)
private void	checkAccess(int arrayLength, int index)
TypedValue	getValueInternal(ExpressionState state)
private boolean	growCollection(ExpressionState state, TypeDescriptor targetType, int index, java.util.Collection collection) Attempt to grow the specified collection so that the specified index is valid.
boolean	isWritable(ExpressionState expressionState) Determine if this expression node will support a setValue() call.
private void	setArrayElement(ExpressionState state, java.lang.Object ctx, int idx, java.lang.Object newValue, java.lang.Class clazz)
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()

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

cachedReadName

private java.lang.String cachedReadName

cachedReadTargetType

private java.lang.Class<?> cachedReadTargetType

cachedReadAccessor

private PropertyAccessor cachedReadAccessor

cachedWriteName

private java.lang.String cachedWriteName

cachedWriteTargetType

private java.lang.Class<?> cachedWriteTargetType

cachedWriteAccessor

private PropertyAccessor cachedWriteAccessor

Constructor Detail

Indexer

public Indexer(int pos,
               SpelNodeImpl expr)

Method Detail

getValueInternal

public TypedValue getValueInternal(ExpressionState state)
                            throws EvaluationException

Specified by:

getValueInternal in class SpelNodeImpl

Throws:

EvaluationException

isWritable

public boolean isWritable(ExpressionState expressionState)
                   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:

expressionState - the current expression state (includes the context)

Returns:

true if the expression node will allow setValue()

Throws:

SpelEvaluationException

setValue

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

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:

EvaluationException - if any problem occurs evaluating the expression or setting the new value

growCollection

private boolean growCollection(ExpressionState state,
                               TypeDescriptor targetType,
                               int index,
                               java.util.Collection collection)

Attempt to grow the specified collection so that the specified index is valid.

Parameters:

state - the expression state

elementType - the type of the elements in the collection

index - the index into the collection that needs to be valid

collection - the collection to grow with elements

Returns:

true if collection growing succeeded, otherwise false

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

setArrayElement

private void setArrayElement(ExpressionState state,
                             java.lang.Object ctx,
                             int idx,
                             java.lang.Object newValue,
                             java.lang.Class clazz)
                      throws EvaluationException

Throws:

EvaluationException

accessArrayElement

private java.lang.Object accessArrayElement(java.lang.Object ctx,
                                            int idx)
                                     throws SpelEvaluationException

Throws:

SpelEvaluationException

checkAccess

private void checkAccess(int arrayLength,
                         int index)
                  throws SpelEvaluationException

Throws:

SpelEvaluationException